History Main / PlotAllergy

* ''Series/BillyTheExterminator'': Ricky is seriously allergic to stinging insects. He still does jobs involving stinging insects, but he is always accompanied by someone else (usually Billy).

** Another victim dies after the Alpha Bitch in the sorority she was pledging replaced the canister in her asthma inhaler with an experimental sexual enhancement drug, and the girl kept using more of it since her breathing kept getting worse and worse. That, combined with the heavy breathing the sex drug triggers, causes her to basically choke to death from a massive orgasm in public.

* In one ''Angela Nicely'' book (a spinoff of ''Literature/DirtyBertie''), Angela mistakes her teacher's red eyes, which are actually due to hay fever, as a sign she's been [[MistakenForBrooding crying]], and tries to cheer her up by [[StudentsPlayingMatchmaker hooking her up with Mr. Weakly]].

* On ''WesternAnimation/JoJosCircus'', [=JoJo=] has a plot allergy to merryberries, a type of berry [[FantasticFlora found only within the show's setting of Circus Town]]. In "Tickled Pink," [=JoJo=] eats some merryberries, which causes her nose to swell and honk and her skin to turn pink and tingly. Fortunately, she visits her friendly family doctor, Skeebo's mother Dr. Seltzer, who gives her an easy cure - to pat her tummy and rub her nose, then rub her tummy and give her nose a pat. The [[AnAesop moral]] of the story is "''So if you feel low / If you feel sad / If allergies make you feel real bad / For upset tummies or aching heads / Listen to your doctor and do what she says / If you wanna get better / Listen to your doctor and do what she says.''" Also "If you are allergic to a food, never eat it because it can make you really, really sick, and don't be afraid to tell someone if you have an allergy."

* ''WesternAnimation/KingOfTheHill'': Bobby suddenly develops an allergy to dog dander late in season 5, which when Hank refuses to put down or otherwise give up Ladybird results in them trying medication and then, when that doesn't seem to work, putting Ladybird in a custom doghouse - which Bobby ends up moving into instead when Ladybird doesn't like it. Lampshaded by the doctor who gives the diagnosis, who tells the Hills that "allergies come and go"; sure enough, Bobby's over the allergy by the halfway point, with the rest of the plot dealing with his refusal to move back out of the doghouse.
* In ''WesternAnimation/MiraculousLadybug'', Adrien/Chat Noir is allergic to feathers, which comes up in the episode where he and Ladybug have to fight a pigeon-themed akuma.
* ''WesternAnimation/MyLittlePonyAndFriends'':
** In "[[Recap/MyLittlePonyAndFriendsE19TheGlassPrincess4 The Glass Princess, Part 4]]", Gusty realizes that she is, of all things, allergic to pigs. Given that their main foe right now is a pig and that constant sneezing makes stealth a touch difficult, this proves to be somewhat of a problem.
** In "[[Recap/MyLittlePonyAndFriendsE33TheMagicCoins3 The Magic Coins, Part 3]]", Niblik is terribly allergic to roses, which very inconveniently for the heroes nixes any value their first treasure, a magic rose, might have for bargaining with him.
* ''WesternAnimation/MyLittlePonyFriendshipIsMagic'':
** In the "Ail-icorn" short, Twilight's powers [[MalfunctionMalady wonk out]] when she gets hay fever.

Can result in a SneezeOfDoom or CongestionSpeak.

* In ''Film/{{Babe}}'', Ferdinand the duck wants to steal the Hoggetts' alarm clock (ItMakesSenseInContext), but he's allergic to cats, so to avoid waking the Hoggetts' [[CatsAreMean mean cat Duchess]] with a SneezeOfDoom, he recruits Babe to sneak into the house and steal the alarm clock for him. HilarityEnsues.

* ''WesternAnimation/{{Baymax}}'': Mbita works a fish soup foodtruck. However, that changes when he develops an allergy toward fish. the premise of his episode is him learning to accept that he can no longer work with fish.
* ''WesternAnimation/TheBotsMaster'' Ziv Zulander and his sister almost fell victims to this trope.

** In "Ail-icorn", Twilight's powers [[MalfunctionMalady wonk out]] when she gets hay fever.

* ''WesternAnimation/TeenTitans'': Starfire's allergy to a metal used in a certain bomb (and lots of other stuff)

* ''WesternAnimation/WanderOverYonder'': In "The Flower", [[spoiler: Lord Dominator is about to crush a dying flower Wander and Sylvia have spent the whole episode trying to save, when it spews a cloud of pollen in her face. Turns out Dominator has hay fever and she starts sneezing uncontrollably, giving Wander and Sylvia time to grab the flower and escape.]]

* In ''WesternAnimation/TheTick'' episode "Bloomsday" Arthur uses his hayfever to track down the missing 400 year bloom.* ''WesternAnimation/ThunderAndTheHouseOfMagic'': Thunder, a magician's cat, uses [[ShadyRealEstateAgent Daniel's]] cat allergies against him in order to keep him out of the house and selling it behind the owner's back. Usually, just a tail across the face or even just simply sitting around inside the house is enough to get him out the door. However, the payout from selling the house [[{{Greed}} is high enough to motivate Daniel]] to keep coming back, and even Daniel [[GenreSavvy wisens up to the tactic over time]], usually by either [[TheNoseKnows using his nose to look for the cat]] or putting on a hazmat suit to venture in the house without risking a breakout, making this an example of both Movement Restriction and Detection Allergy.

* In ''WesternAnimation/TheBoxtrolls'', Archibald's severe lactose intolerance (he swells up from a tiny sliver of ''extra mild'' Cheddar) is part of what prevents him from joining the White Hats [[spoiler:and eventually leads to his KarmicDeath]].

* In ''WesternAnimation/PoundPuppiesAndTheLegendOfBigPaw'', the main villain Marvin [=McNasty=] happens to be allergic to cats. Cooler eventually takes advantage of this when [=McNasty=] orders his henchmen Lumpy and Bones to take away the Pound Purries Hairball and Charlemange by disguising himself as cat so he'd be taken out of [=McNasty=]'s house with the Pound Purries.

** There a case where some guys played a prank on another guy by lacing his soup with shellfish. He went into anaphylaxis and grabbed for his medication, but the guys had replaced it with an empty one. He died before help arrived.

** Late in season 8, it is revealed that Mac is deathly allergic to blueberries.

* In the ''WesternAnimation/PetAlien'' episode "Terror in my Nose", Tommy suddenly becomes allergic to Dinko to the point where simply getting close sends him into a sneezing fit. It turns out that this is because Dinko forgot to put on hair gel that day; the scent of the gel blocks Dinko's own scent and allows Tommy to be around him without his allergies acting up.

* ''Film/IronMan2'': Tony remembers that strawberries are important to Pepper Potts for some reason but can't remember what exactly the reason is, so he buys a pint from a roadside stand as a gift. When he presents them to her, she tells him with some exasperation that she's allergic to them.

* In ''Film/TheIncident2014'', two parallel allergies, one to fruit juice and one to bees, drive the intersecting time loops.* ''Film/LoveInTheVilla'': Charlie is deathly allergic to cats, which is unfortunate for him as the piazza is full of them. Julie lures them into his bedroom in an attempt to get him to leave the villa.

* ''WesternAnimation/{{Arthur}}'' has an episode in which Binky is revealed to be allergic to peanuts, for similar reasons as the above ''Daniel Tiger'' example. Binky's peanut allergy is occasionally mentioned in later installments.

* ''WesternAnimation/TheGhostAndMollyMcGee'': In "Innocent Until Proven Ghostly", Scratch is accused of eating a cake that Molly's dad made as an anniversary gift. Scratch insists he didn't touch the cake, even when the evidence points in his direct. Molly realizes why when she remembers the cake contains carob, and clears Scratch's name by revealing that he has a carob allergy (which isn't fatal, since he's a ghost, but still causes his body to temporarily swell until it fills the house).

* ''WesternAnimation/ThunderAndTheHouseOfMagic'': Thunder, a magician's cat, uses [[ShadyRealEstateAgent Daniel's]] cat allergies against him in order to keep him out of the house and selling it behind the owner's back. Usually, just a tail across the face or even just simply sitting around inside the house is enough to get him out the door. However, the payout from selling the house [[{{Greed}} is high enough to motivate Daniel]] to keep coming back, and even Daniel [[GenreSavvy wisens up to the tactic over time]], usually by either [[TheNoseKnows using his nose to look for the cat]] or putting on a hazmat suit to venture in the house without risking a breakout, making this an example of both Movement Restriction and Detection Allergy.

[[folder:Unsorted]]
* In ''[[WesternAnimation/DragonsRidersOfBerk Dragons: Race to the Edge]]'', Fishlegs starts sneezing a lot and becoming strangely itchy, especially when around his dragon Meatlug. He later discovers that Gobber had been using his own earwax on Meatlug's saddle, and that's what he was allergic to, causing Fishlegs to note that he's both "relieved and disturbed".
* ''WesternAnimation/{{Franklin}}'' had one in which Franklin kept sneezing. The characters tested a number of possible causes and finally concluded that he was allergic to his best friend, Bear, as he only sneezed when he was around Bear or handled things that Bear gave to him. The two stayed apart for a while, but Franklin eventually decided he didn't mind sneezing if he could play with his best friend. He then found that he didn't sneeze around Bear when Bear was covered in mud. Then, when he went to Bear's house, he got a bath and it was discovered that it was actually the new bubble bath that Bear was using that was causing the sneezing.
* In ''[[http://rugratonline.free.fr/rrfan40.html Kitten Companions]]'', [[WesternAnimation/{{Rugrats}} Chas Finster]] thinks he's allergic to cats when he actually has hay fever.
* On ''WesternAnimation/PegPlusCat'' in "The Allergy Problem," Peg fears that she might be allergic to Cat, but turns out to actually be allergic to four-leaf clovers. They make her sneeze. This one can be chalked up as ArtisticLicenseBiology, since four-leaf covers aren't chemically any different from regular clovers, they just have an extra leaf. If four-leaf clovers caused someone to sneeze, then surely regular ones would as well (though perhaps she is allergic to all clovers, sicne the four-leafed one was just the one that was under her hat).
* In ''WesternAnimation/{{Rugrats}}'', the babies believe Chuckie is allergic to Kimi since he begins to sneeze whenever she's near him or passes by him. Fearing that the adults would get rid of her if they find out, they try to keep him away from Kimi. It later turned out that Kimi had a bunch of dandelions in her diaper which she was planning to give to Chuckie as a gift.
* In the ''WesternAnimation/SpongeBobSquarepants'' episode "Unreal Estate," Squidward purposefully evokes this trope by filling [=SpongeBob's=] foghorn alarm clock with [[PepperSneeze pepper]] to make him sneeze nonstop and think he's allergic to his pineapple house, forcing him to move away.
* In ''WesternAnimation/TheSimpsons'', Bart finds out about Principal Skinner's allergy (peanuts) and uses it to manipulate him; later it turns out Bart has a similar allergy (shrimp) and violence ensues. This is not mentioned elsewhere, and Bart has had no problem eating at the Frying Dutchman seafood restaurant.
* The ''WesternAnimation/{{Arthur}}'' episode "Poor Muffy" has Muffy need to move in with Francine for a week due to an allergy to her carpets.
* In one episode of ''Dudley Do-Right'', Dudley reveals to Nell that he's allergic to marigolds. Snidely Whiplash finds out and creates a suit made of marigolds so Dudley can't arrest him.
* ''WesternAnimation/TheRealGhostbusters'': Subverted in "Something's Coming Around", where Peter appears sick, and a doctor claims that he's allergic to ghosts and has to resign from his job as a ghost hunter, but it turns out that the doctor is [[MadDoctor evil]] and caused the symptoms in Peter (and later, the rest of the Ghostbusters) using supernatural potato chips.

* In ''WesternAnimation/TheSimpsons'', when Homer gets a job with [[AffablyEvil Hank Scorpio]] and moves to Cypress Creek, Lisa is allergic to the pollen from the plants that grow there, and is one of the reasons why they had to [[StatusQuoIsGod move back to Springfield]].


* ''Black Widow''. BlackWidow Catharine Petersen marries men and murders them by giving them a substance to which they have a lethal allergy.
* ''WesternAnimation/TheBotsMaster'' Ziv Zulander and his sister almost fell victims to this trope.
* The ''WesternAnimation/{{Duckman}}'' episode "Days of Whining and Neurosis" features a [[PopGoesTheHuman grotesque murder]] by lactose intolerance.

* In ''WesternAnimation/CentralPark'', Molly takes a chance to kiss her crush Brendan, only for it to trigger his peanut allergy since she had just eaten Peanut Butter Parfait ice cream. His face swells up and he has to give himself an epipen injection before staggering off. The plot continues into the next episode, when Brendan doesn't text Molly back and a rumor spreads at her school about a girl who killed a boy from a different school because of a "peanut butter kiss". Molly worries that she either killed Brendan, or that he survived and won't forgive her (it turns out to be neither - Brendan accidentally left his phone with Molly, which Molly forgot).
* ''WesternAnimation/DuckTales1987'', "[[Recap/DuckTalesADuckTalesValentine A DuckTales Valentine]]": The kids convince Aphroducky that she's allergic to money so that Scrooge will be forced to choose between her and his fortune. Unfortunately, it doesn't have the desired effect.


* One ''WesternAnimation/GarfieldAndFriends'' episode, his owner Jon finally finds a girl...But it turns out that she is allergic to cats at the very end, and the [[StatusQuoIsGod status quo]] is restored.
* ''WesternAnimation/WallaceAndGromit'': Wallace's first potential love interest (Wendolene) is allergic to dairy, dooming the relationship since Wallace's TrademarkFavoriteFood is cheese and he can't bear to be without someone who doesn't also eat it.



* One ''WesternAnimation/DonaldDuck'' comic has Donald receive 1 million dollars from a stranger, but when he uses some of it to pay off a debt to [[ComicBook/DisneyDucksComicUniverse Scrooge McDuck]], Scrooge immediately starts sneezing; it turns out the money is counterfeit, and Scrooge is allergic to counterfeit money.
* In ''WesternAnimation/MiraculousLadybug'', Adrien/Chat Noir is allergic to feathers, which comes up in the episode where he and Ladybug have to fight a pigeon-themed akuma.

* In ''WesternAnimation/ScoobyDooMysteryIncorporated'', Daphne's allergies have been the key to major clues at least twice. In episode 2, the fake gator belts setting off her allergy to imitation animal products lets the kids crack the counterfeit gator ring, while in episode 4, her lack of a reaction to the Man-Crab despite a severe seafood allergy clues Velma in to the fact that the Man-Crab isn't really a crab.
* ''WesternAnimation/TheSecretOfNIMH'': Jeremy's cat allergy, warning them that the farmer's cat is near and distracting him when Dragon does arrive.
* In ''WesternAnimation/StormHawks'', Junko is allergic to Murk Raiders and Sky Sharks, both of which cause him to release Sneezes of Doom.
* ''WesternAnimation/TeenTitans'': Starfire's allergy to a metal used in a certain bomb (and lots of other stuff)
* In ''WesternAnimation/TheTick'' episode "Bloomsday" Arthur uses his hayfever to track down the missing 400 year bloom.[[/folder]]

* ''ComicBook/SonicTheHedgehogArchieComics'' use this with Pseudo Sonic. Sonic ends up being launched into a field of flowers which causes him to swell up like a balloon. Tails saves the day in both adaptations, but the comic has Bunnie Rabbot coming to Sonic's rescue before Robotnik can get rid of him.

[[/folder]]

* In ''Film/TheIncident2014'', two parallel allergies, one to fruit juice and one to bees, drive the intersecting time loops.

* Haruka from ''VisualNovel/LittleBusters'' loves making egg dishes - [[OneNoteChef in fact, they're the only thing she can cook at all]] - because she believes that [[spoiler:Kanata]] has an allergy to eggs, so Haruka wants to assert this as the one place she is truly the best.

* In ''[[https://archiveofourown.org/works/35402485/chapters/88242349?view_adult=true Sick]]'', [[Film/Ghostbusters1984 Egon]] thinks he is allergic to Ray's clothes or detergent, but actually [[UnknowinglyInLove he has a crush on him.]]

* ''Film/LoveInTheVilla'': Charlie is deathly allergic to cats, which is unfortunate for him as the piazza is full of them. Julie lures them into his bedroom in an attempt to get him to leave the villa.
* Both ''WesternAnimation/AdventuresOfSonicTheHedgehog'' and

* In ''Film/{{Babe}}'', Ferdinand the duck wants to steal the Hoggetts' alarm clock (ItMakesSenseInContext), but he's allergic to cats, so to avoid waking the Hoggetts' [[CatsAreMean mean cat Duchess]] with a SneezeOfDoom, he recruits Babe to sneak into the house and steal the alarm clock for him. HilarityEnsues.
* ''WesternAnimation/CloudyWithAChanceOfMeatballs'': Sam's peanut allergy prevents her from going down to the food-making machine with Flint through a pit surrounded by shards of peanut brittle. She lowers him down using a licorice rope, [[spoiler:but she gets stabbed by one of the shards and starts to swell up. Flint cuts the rope and goes to the machine alone, while Brent takes Sam back to get her antidote shot. When Sam first revealed her allergy to Flint, he ''claimed'' to have the same allergy, but was lying in order to try to make himself seem more attractive to her.]]

* The fourth episode of ''VideoGame/FarnhamFables'' is a DreamEpisode starring Theresa Doyle, who is severely allergic to peanuts. In her dream, she has to find the Rainbow Keys so she can create a bridge across a river of peanut butter.

* ''Webcomic/CryptsAndCantrips'': Turns out [[spoiler: The king]] is allergic to a posion that should have taken weeks or month to kill him, so instead he dies within hours.

* In the 1998 ''Film/{{Madeline}}'' film, Miss Clavel is allergic to dogs. Her own sneezing alerts her to the fact that the girls have broken the "no pets" rule and are hiding a dog in the school. Still, she lets them keep Genevieve as long as they keep her outside.
* In ''Film/TheOccupant'', Tomas is established to be extremely allergic to peanuts. [[spoiler:Javier injects peanut extract into a can of pepper spray and then engineers the situation for Javier to be sprayed, his death covered up as a bad reaction to the pepper spray]].

* In ''Webcomic/LasLindas'', during the 'party' arc, Miles' TheReasonYouSuckSpeech for his girlfriend/ex-girlfriend Taffy gets countered by one of these. When he complains that he'd never know if "one more bouquet of flowers" could get her to finally put out, she simply says "I'm allergic to flower pollen. You'd know that if you'd ever gotten me any." Ouch.
** Also, atypically enough, her flower allergy ''did'' come up earlier, in a non-romantic example of this trope - Digit tried to give her a bunch of flowers to say she was sorry about a previous mishap, only for the flower allergy to ruin her attempt.

* On ''ComicStrip/MaryWorth'' storyline had Mary acquire a cat, then discover her boyfriend Dr Jeff was allergic. She managed to get the cat rehomed with one of her neighbours.
* In ''Webcomic/PvP'', at one point, Skull the Troll briefly dates a girl who works in a nearby cafeteria. A while later, a mutual friend reminds him that he's been neglecting her, and he rushes off to see her with some flowers. Only, it turns out that she's allergic to them, and he's forgotten it. He knew that might happen, and ALSO brought chocolates. Which, as it turns out, she's ''also'' allergic to.
* ''Webcomic/QuestionableContent'':
** A bump on the road in Faye's relationship [[http://questionablecontent.net/view.php?comic=1123 here]] with Angus happens when she give him a coffee with milk and he ends up spending some time in the toilet in gastrointestinal distress.
** Shortly after Marten starts dating Dora, he surprises her with some roses. The inevitable result is anaphylactic shock, but contrary to the more common results of this trope, Dora actually feels sorry for Marten since he's had an attempt at romance blow up in his face...

* ''VisualNovel/{{Snatcher}}'' uses a Detection Allergy - the eponymous robots release a masking agent called SNOW-9 which is similar to pollen, causing people (including the protagonist) to sneeze when they're in the area.

* In ''Ultimate Hangout'', based on ''WesternAnimation/TheLoudHouse'', Clyde is allergic to geese and uses goose feathers to make himself sneeze and get his fathers' attention.

* Neither Cameron nor Foreman can eat a certain dessert in the ''Series/{{House}}'' fanfic "Inferno" because she's allergic to chocolate and he's allergic to pecans, and it contains both.

* In ''Eppie the Elephant Who was Allergic to Peanuts'', Eppie has to ask her friends not to sit next to her at school if they're having peanuts since she's allergic to them. Her friends are notably [[StockAnimalDiet surprised that an elephant could be allergic to peanuts]].

* In the ''Series/DennisTheMenace'' episode "Wilson's Allergy," Mr. Wilson starts sneezing whenever he's around Dennis, but in the end he turns out to be allergic to a hair tonic that Dennis has secretly been using.* In ''Series/DumbosCircus'', Dumbo is allergic to flowers. Since he's not a baby anymore in this series, but an almost full-grown elephant, his allergy results in frequent [[SneezeOfDoom Sneezes of Doom]] that blow things around or knock them down.

* ''Literature/MillyMolly'':
** One episode reveals that Miss Blythe the teacher is allergic to mice, which causes her to run around screaming and sneezing when Harry brings his pet mice to school.
** In "Cats Alive", the girls try to give a cat to a shopkeeper, but he says no on account of being, as he puts it, "allergic to pets".

* In the ''Literature/ElephantAndPiggie'' book ''Pigs Make Me Sneeze'', Gerald thinks he's allergic to Piggie, but really he just has a cold... which Piggie catches from him.

* In an old ''ComicBook/SupermansPalJimmyOlsen'' comic, Jimmy notices a funny ticking sound whenever he's around Superman, which he thinks is his heart. He concludes he has an allergy to the Man of Steel and must stay away until he can find a way out of it, or he risks death by heart attack. He eventually figures out that it was his signal watch, which malfunctioned and ticked whenever it was around gold.

* ''Series/StargateAtlantis'': Rodney [=McKay=] is mortally allergic to citrus. In "The Pegasus Project", before sending [=McKay=] off to help [[Series/StargateSG1 SG-1]] on a mission, Sheppard gives Mitchell a lemon in case [=McKay=] gets out of hand. Later, when [=McKay=] claims that the mission is impossible, the lemon makes a reappearance.
-->'''[=McKay=]:''' What stories? What have you heard?\\
'''Mitchell:''' Well, for starters, that you didn't know the meaning of the word "impossible"... and that under threat of impending death, you could work absolute miracles.\\
'''[=McKay=]:''' Yes, well it's all true, but I'm not under the threat of impending death, and I don't have a--\\
(''Mitchell pulls out the lemon and holds it up to Rodney's face'')\\
'''[=McKay=]:''' ...Well, I'll see what I can come up with, then.

* Both ''WesternAnimation/AdventuresOfSonicTheHedgehog'' and ''ComicBook/SonicTheHedgehogArchieComics'' use this with Pseudo Sonic. Sonic ends up being launched into a field of flowers which causes him to swell up like a balloon. Tails saves the day in both adaptations, but the comic has Bunnie Rabbot coming to Sonic's rescue before Robotnik can get rid of him.
* In ''[[https://www.fanfiction.net/s/7191052/1/Allergies Allergies]]'' Dudley and his gang are forced to leave the school library because a hiding Harry's desperate wish magic makes them allergic to it.

* In ''Fanfic/HigherFlier'', Dainty Dish is allergic to almost everything under the clouds, and her constant sneezing takes a huge toll on her stamina, making her a poor flyer at low altitudes. [[spoiler: At higher altitudes, away from her allergens, she's the fastest Pegasus in Equestria.]]
* ''Literature/LizardMusic'': One of the reasons Victor's staying at home the summer the story takes place instead of going to camp with his peers is because he found out he was allergic to most of the plants when he went to camp the previous year.

* In ''ComicBook/{{Runaways}}'', Gert doesn't want to fight a Nazi made of bees because she is allergic to them.

* In the ''Series/DonkeyHodie'' episode "Growing the Ungrowdenia'', we learn that Clyde can't be by flowers because he is allergic to them. This, among other problems, causes Donkey to try to ungrow the titular flower.
* In the ''Literature/BenjaminJanuary'' series, one book has a murderer poison his victim's dinner with something he was violently allergic to. Since there's no widespread awareness that food allergies even exist, much less that the victim had one, nobody thinks he could have been poisoned by something that everyone else ate.

* ''Literature/TheDaVinciCode'': [[spoiler: Leigh]] disposes of a butler who knew too much and was allergic to peanuts by putting peanut dust in his wine.
* The ''WesternAnimation/{{Duckman}}'' episode "Days of Whining and Neurosis" features a [[PopGoesTheHuman grotesque murder]] by lactose intolerance.
* In the last book of the ''Literature/EmpireOfTheAnts'' trilogy, the protagonist's uncle dies near the secret base because he turns out to be allergic to their sedative.
* ''Series/HouseMd'': In Season 5, House subconsciously attempts to kill [[spoiler:Chase]] with his strawberry allergy by hiring a stripper to the latter's bachelor party who uses strawberry body butter. House only realizes what he did when he learns of [[spoiler:Chase]]'s an anaphylactic shock and deems his hallucination of [[spoiler:Amber]] dangerous.
* In the ''Series/MidsomerMurders'' episode "Red in Tooth & Claw", someone places rabbit fur in the ducts of Cleo Langton's car. Turning on the A.C. system with the windows closed triggers her allergy to rabbits, and someone had removed the allergy medication from her purse, so she dies by respiratory failure.
* One episode of ''Series/MurdochMysteries'' has the victim of the week, who was allergic to peanuts, die when the rim of the cup they were drinking out of was coated with peanut oil. Another has the victim killed ''in jail'' by replacing the cook's vegetable oil with soya oil, which had no effect on the other prisoners.
* In ''Literature/OneOfUsIsLying'', Simon is killed with peanut oil, which he is allergic to, in his water.

* In ''Fanfic/WhereTalentGoesToDie'', the second victim is killed by ingesting peanuts, to which he is allergic. The second motive had made the students aware of one another's weaknesses, and after the students learn about his allergy, they must discover who knew about it before the murder and had the opportunity to poison him.
* In ''Anime/TheCatReturns'', the cats fill Haru's front garden with cattails. In the English dub she later tells the messenger that she's allergic to them. (Actually a slight change from the Japanese version, but given that Haru woke up sneezing the morning after they were planted it's hardly contradictory.).
** Though this definitely doesn't apply to the manga version of the same scene, as the cattails were planted elsewhere. It may be that Haru was just [[FreezeSneeze sneezing from the cold, as she'd been sleeping largely uncovered]].

* In ''Series/{{Cheers}}'' episode "[[Recap/CheersS3E10 Diane's Allergy]]", Diane develops a psychosomatic allergy, driven by her anxiety over moving into her boyfriend Frasier's apartment.

* Yuuto, the male lead of ''Manga/OmamoriHimari'', is allergic to cat hair. His bodyguard (and member of his UnwantedHarem) Himari is a cat demon.

* [[WesternAnimation/TheLoudHouse Lola Loud]] tries to invoke this in ''[[https://www.deviantart.com/jgodzilla1212/art/The-Loud-House-Fanfic-38-Rome-No-and-Juli-Nyet-905783633 Rome-No and Juli-Nyet]]'', since Lindsey is allergic to pickles and this led to her developing an irrational hatred for them, so she tries to dump her in pickle juice and frame her [[PuppyLove boyfriend]] Winston for it, so that [[LoveTriangle she will dump him and he can date Lola]].
* Lana's kryptonite necklace pendant in season 1 of ''Series/{{Smallville}}'' causes this trope in Clark.
* A teenager on ''Series/UntoldStoriesOfTheER'' nearly killed her peanut-allergic boyfriend - twice - by French-kissing him, because she assumed brushing her teeth was enough to eliminate any residue from the peanut-butter sandwich she'd had for lunch. The second time, the two of them had smooched in the ER to celebrate how his ''first'' brush with anaphylaxis had been brought under control.

* The Eighth Doctor does this in the [[AudioPlay/BigFinishDoctorWho Big Finish]] ''Series/DoctorWho'' episode "Caerdroia", where it turns out that the exact time portals they're looking for give him time sickness just by standing next to them. His two companions delight in dragging him around the field as a living detector device while he struggles to keep standing up.

* In the ''Literature/{{Goosebumps}}'' book ''I Am Your Evil Twin'', the main character uses his peanut allergy to distinguish himself from his evil clone--since they aren't sure how allergies work, he supposes that the clone might not have it. (After the climactic test, though, it turns out that the clone swapped out the test food for one that he wasn't allergic to, and then made himself throw up so everyone would think he was the real thing.)
* In the 1998 ''Film/{{Madeline}}'' film, Miss Clavel is allergic to dogs. Her own sneezing alerts her to the fact that the girls have broken the "no pets" rule and are hiding a dog in the school. Still, she lets them keep Genevieve as long as they keep her outside.

* In the ''Series/MurderSheWrote'' episode "[[Recap/MurderSheWroteS3E12CrossedUp Crossed Up]]", Jessica originally can't figure out which of the relatives put out the hit, because none of them have raspy voices. However, then the family appears on TV. [[spoiler: Gordon Rogers]] is holding [[spoiler: his wife's new]] Persian cat, to which they're allergic. The allergies roughen their voice, creating the raspiness Jessica heard.
* ''Series/{{NCIS}}'': [=McGee=] is allergic to a cologne of a suspect, later a body turns up that causes [=McGee=] to sneeze.
* Taken Up to Eleven by Ruby "Pufferfish" Peet in ''Literature/{{NERDS}}''. This child's allergies are so severe that they actually go off whenever she's exposed to things such as danger, threats, dishonesty, and betrayal. Making her a human danger detector.

* In ''WesternAnimation/TheTick'' episode "Bloomsday" Arthur uses his hayfever to track down the missing 400 year bloom.
* In the ''Literature/WarriorCats'' novella ''Pebbleshine's Kits'', Pebbleshine hides in a car, hoping it'll bring her back to where she lost her Clan, but is detected by the humans who own it when their child starts sneezing uncontrollably - turns out she's allergic to cats.
[[/folder]]

!!Examples: (separated into types)

[[folder:'''The movement restriction allergy''' \\
"I can't go there! I'm allergic to X!"]]

* Both ''WesternAnimation/AdventuresOfSonicTheHedgehog'' and ''ComicBook/SonicTheHedgehogArchieComics'' use this with Pseudo Sonic. Sonic ends up being launched into a field of flowers which causes him to swell up like a balloon. Tails saves the day in both adaptations, but the comic has Bunnie Rabbot coming to Sonic's rescue before Robotnik can get rid of him.
* In ''[[https://www.fanfiction.net/s/7191052/1/Allergies Allergies]]'' Dudley and his gang are forced to leave the school library because a hiding Harry's desperate wish magic makes them allergic to it.
* The ''WesternAnimation/{{Arthur}}'' episode "Poor Muffy" has Muffy need to move in with Francine for a week due to an allergy to her carpets.
* In ''Film/{{Babe}}'', Ferdinand the duck wants to steal the Hoggetts' alarm clock (ItMakesSenseInContext), but he's allergic to cats, so to avoid waking the Hoggetts' [[CatsAreMean mean cat Duchess]] with a SneezeOfDoom, he recruits Babe to sneak into the house and steal the alarm clock for him. HilarityEnsues.
* ''WesternAnimation/CloudyWithAChanceOfMeatballs'': Sam's peanut allergy prevents her from going down to the food-making machine with Flint through a pit surrounded by shards of peanut brittle. She lowers him down using a licorice rope, [[spoiler:but she gets stabbed by one of the shards and starts to swell up. Flint cuts the rope and goes to the machine alone, while Brent takes Sam back to get her antidote shot. When Sam first revealed her allergy to Flint, he ''claimed'' to have the same allergy, but was lying in order to try to make himself seem more attractive to her.]]
* In one episode of ''Dudley Do-Right'', Dudley reveals to Nell that he's allergic to marigolds. Snidely Whiplash finds out and creates a suit made of marigolds so Dudley can't arrest him.
* The fourth episode of ''VideoGame/FarnhamFables'' is a DreamEpisode starring Theresa Doyle, who is severely allergic to peanuts. In her dream, she has to find the Rainbow Keys so she can create a bridge across a river of peanut butter.
* In ''Fanfic/HigherFlier'', Dainty Dish is allergic to almost everything under the clouds, and her constant sneezing takes a huge toll on her stamina, making her a poor flyer at low altitudes. [[spoiler: At higher altitudes, away from her allergens, she's the fastest Pegasus in Equestria.]]
* ''Literature/LizardMusic'': One of the reasons Victor's staying at home the summer the story takes place instead of going to camp with his peers is because he found out he was allergic to most of the plants when he went to camp the previous year.
* ''WesternAnimation/TheRealGhostbusters'': Subverted in "Something's Coming Around", where Peter appears sick, and a doctor claims that he's allergic to ghosts and has to resign from his job as a ghost hunter, but it turns out that the doctor is [[MadDoctor evil]] and caused the symptoms in Peter (and later, the rest of the Ghostbusters) using supernatural potato chips.
* In ''ComicBook/{{Runaways}}'', Gert doesn't want to fight a Nazi made of bees because she is allergic to them.
* In ''WesternAnimation/TheSimpsons'', when Homer gets a job with [[AffablyEvil Hank Scorpio]] and moves to Cypress Creek, Lisa is allergic to the pollen from the plants that grow there, and is one of the reasons why they had to [[StatusQuoIsGod move back to Springfield]].
* In the ''Series/DonkeyHodie'' episode "Growing the Ungrowdenia'', we learn that Clyde can't be by flowers because he is allergic to them. This, among other problems, causes Donkey to try to ungrow the titular flower.

[[folder: '''The relationship hitch allergy''' \\
"My new girlfriend has a cat/sent me flowers, guess what I'm allergic to"]]

* In ''Anime/TheCatReturns'', the cats fill Haru's front garden with cattails. In the English dub she later tells the messenger that she's allergic to them. (Actually a slight change from the Japanese version, but given that Haru woke up sneezing the morning after they were planted it's hardly contradictory.).
** Though this definitely doesn't apply to the manga version of the same scene, as the cattails were planted elsewhere. It may be that Haru was just [[FreezeSneeze sneezing from the cold, as she'd been sleeping largely uncovered]].
* In ''WesternAnimation/CentralPark'', Molly takes a chance to kiss her crush Brendan, only for it to trigger his peanut allergy since she had just eaten Peanut Butter Parfait ice cream. His face swells up and he has to give himself an epipen injection before staggering off. The plot continues into the next episode, when Brendan doesn't text Molly back and a rumor spreads at her school about a girl who killed a boy from a different school because of a "peanut butter kiss". Molly worries that she either killed Brendan, or that he survived and won't forgive her (it turns out to be neither - Brendan accidentally left his phone with Molly, which Molly forgot).
* In ''Series/{{Cheers}}'' episode "[[Recap/CheersS3E10 Diane's Allergy]]", Diane develops a psychosomatic allergy, driven by her anxiety over moving into her boyfriend Frasier's apartment.
* ''WesternAnimation/DuckTales1987'', "[[Recap/DuckTalesADuckTalesValentine A DuckTales Valentine]]": The kids convince Aphroducky that she's allergic to money so that Scrooge will be forced to choose between her and his fortune. Unfortunately, it doesn't have the desired effect.
* In ''Webcomic/LasLindas'', during the 'party' arc, Miles' TheReasonYouSuckSpeech for his girlfriend/ex-girlfriend Taffy gets countered by one of these. When he complains that he'd never know if "one more bouquet of flowers" could get her to finally put out, she simply says "I'm allergic to flower pollen. You'd know that if you'd ever gotten me any." Ouch.
** Also, atypically enough, her flower allergy ''did'' come up earlier, in a non-romantic example of this trope - Digit tried to give her a bunch of flowers to say she was sorry about a previous mishap, only for the flower allergy to ruin her attempt.
* One ''WesternAnimation/GarfieldAndFriends'' episode, his owner Jon finally finds a girl...But it turns out that she is allergic to cats at the very end, and the [[StatusQuoIsGod status quo]] is restored.
* On ''ComicStrip/MaryWorth'' storyline had Mary acquire a cat, then discover her boyfriend Dr Jeff was allergic. She managed to get the cat rehomed with one of her neighbours.
* Yuuto, the male lead of ''Manga/OmamoriHimari'', is allergic to cat hair. His bodyguard (and member of his UnwantedHarem) Himari is a cat demon.
* In ''Webcomic/PvP'', at one point, Skull the Troll briefly dates a girl who works in a nearby cafeteria. A while later, a mutual friend reminds him that he's been neglecting her, and he rushes off to see her with some flowers. Only, it turns out that she's allergic to them, and he's forgotten it. He knew that might happen, and ALSO brought chocolates. Which, as it turns out, she's ''also'' allergic to.
* ''Webcomic/QuestionableContent'':
** A bump on the road in Faye's relationship [[http://questionablecontent.net/view.php?comic=1123 here]] with Angus happens when she give him a coffee with milk and he ends up spending some time in the toilet in gastrointestinal distress.
** Shortly after Marten starts dating Dora, he surprises her with some roses. The inevitable result is anaphylactic shock, but contrary to the more common results of this trope, Dora actually feels sorry for Marten since he's had an attempt at romance blow up in his face...
* [[WesternAnimation/TheLoudHouse Lola Loud]] tries to invoke this in ''[[https://www.deviantart.com/jgodzilla1212/art/The-Loud-House-Fanfic-38-Rome-No-and-Juli-Nyet-905783633 Rome-No and Juli-Nyet]]'', since Lindsey is allergic to pickles and this led to her developing an irrational hatred for them, so she tries to dump her in pickle juice and frame her [[PuppyLove boyfriend]] Winston for it, so that [[LoveTriangle she will dump him and he can date Lola]].
* Lana's kryptonite necklace pendant in season 1 of ''Series/{{Smallville}}'' causes this trope in Clark.
* A teenager on ''Series/UntoldStoriesOfTheER'' nearly killed her peanut-allergic boyfriend - twice - by French-kissing him, because she assumed brushing her teeth was enough to eliminate any residue from the peanut-butter sandwich she'd had for lunch. The second time, the two of them had smooched in the ER to celebrate how his ''first'' brush with anaphylaxis had been brought under control.
* ''WesternAnimation/WallaceAndGromit'': Wallace's first potential love interest (Wendolene) is allergic to dairy, dooming the relationship since Wallace's TrademarkFavoriteFood is cheese and he can't bear to be without someone who doesn't also eat it.

[[folder: '''The false-alarm relationship hitch allergy''' \\
"I think I'm allergic to a person/animal, but really I'm allergic to something on or near them."]]

* In the ''Series/AdventuresInWonderland'' episode "Something to Sneeze At," the Mad Hatter starts sneezing whenever he's near the March Hare and they think they can never share a tea party again. But in the end they realize he's allergic to the flowers the Hare has been wearing in his lapel.
* In an early episode of ''Series/TheBradyBunch'', "Katchoo," Jan develops an allergy to [[ADogNamedCat Tiger]], the pet dog. They plan to give the dog away. But then Jan discovers that she's not allergic to Tiger, she's just allergic to Tiger's new flea powder. (Ironically this was the last episode to feature Tiger as a major character - it's not that somebody was allergic to him, it's that the original RealLife dog actor (also named Tiger) [[TheCharacterDiedWithHim was hit by a florist truck and died from his injuries before the filming for this particular episode was completed.]] One other episode talks about Tiger a lot but he's not actually on screen much - he's missing.)
* In an episode of ''WesternAnimation/CatDog'' "Sneezie Dog," Dog suddenly develops an allergy. They go to the doctor, who thinks that Dog may be allergic to Cat. Winslow decides to help Dog out, and takes the opportunity to torture Cat, as usual, up to shaving him bald and placing a brick wall between them. Eventually they find out Dog is actually allergic to ''Winslow'', and they shave him bald as payback.
* In the ''Series/DennisTheMenace'' episode "Wilson's Allergy," Mr. Wilson starts sneezing whenever he's around Dennis, but in the end he turns out to be allergic to a hair tonic that Dennis has secretly been using.
* In ''[[WesternAnimation/DragonsRidersOfBerk Dragons: Race to the Edge]]'', Fishlegs starts sneezing a lot and becoming strangely itchy, especially when around his dragon Meatlug. He later discovers that Gobber had been using his own earwax on Meatlug's saddle, and that's what he was allergic to, causing Fishlegs to note that he's both "relieved and disturbed".
* In the ''Literature/ElephantAndPiggie'' book ''Pigs Make Me Sneeze'', Gerald thinks he's allergic to Piggie, but really he just has a cold... which Piggie catches from him.
* In the ''Series/FamilyAffair'' episode "The Award," Jody and Buffy start to constantly itch, and Uncle Bill worries that they've developed a psychosomatic allergy because he's been overly strict with them. But actually they're allergic to the modeling clay they've been secretly using to make a "Best Uncle Award" sculpture for Bill.
* ''WesternAnimation/{{Franklin}}'' had one in which Franklin kept sneezing. The characters tested a number of possible causes and finally concluded that he was allergic to his best friend, Bear, as he only sneezed when he was around Bear or handled things that Bear gave to him. The two stayed apart for a while, but Franklin eventually decided he didn't mind sneezing if he could play with his best friend. He then found that he didn't sneeze around Bear when Bear was covered in mud. Then, when he went to Bear's house, he got a bath and it was discovered that it was actually the new bubble bath that Bear was using that was causing the sneezing.
* In the ''Series/GilligansIsland'' episode "Allergy Time," first the Skipper, then all the other castaways suddenly start sneezing when they're around Gilligan. But in the end, it turns out they're not allergic to him, but to the papaya nut oil he's been using as hair tonic.
* In the ''Series/HappyDays'' episode "The Fonz is Allergic to Girls," [[ExactlyWhatItSaysOnTheTin the Fonz starts sneezing whenever he's around girls]] and thinks he'll have to give up his [[TheCasanova Casanova]] ways. But it ultimately turns out that he's allergic to a chemical reaction between his own aftershave and the girls' perfume.
* In ''[[http://rugratonline.free.fr/rrfan40.html Kitten Companions]]'', [[WesternAnimation/{{Rugrats}} Chas Finster]] thinks he's allergic to cats when he actually has hay fever.
* In the ''Series/MisterEd'' episode "Ed the Sentry," Wilbur's wife Carol apparently becomes allergic to Ed. Actually, she's allergic to the straw hat he's wearing.
* ''Series/MorkAndMindy'': In "Mork Gets Mindy-itis", Mork thinks he's become allergic to Mindy since he starts sneezing when she's nearby, but it turns out that he's just afraid of being near people in general (since he's an alien and his species apparently sneezes when they're afraid).
* In the ''[[Series/ThePattyDukeShow Patty Duke Show]]'' episode "The Friendship Bit," Patty starts sneezing whenever she's near Cathy, and is presumed to have developed a psychosomatic allergy because she's jealous of Cathy's achievements in school. But in the end she turns out to be allergic to Cathy's new pin.
* On ''WesternAnimation/PegPlusCat'' in "The Allergy Problem," Peg fears that she might be allergic to Cat, but turns out to actually be allergic to four-leaf clovers. They make her sneeze. This one can be chalked up as ArtisticLicenseBiology, since four-leaf covers aren't chemically any different from regular clovers, they just have an extra leaf. If four-leaf clovers caused someone to sneeze, then surely regular ones would as well (though perhaps she is allergic to all clovers, sicne the four-leafed one was just the one that was under her hat).
* In the ''Series/PetticoatJunction'' episode "I'm Allergic to Daddy," Steve and Betty Jo's baby daughter Kathy Jo develops a rash whenever her father comes home, forcing him to stay in a hotel. But eventually they realize she's allergic to the insecticide on his clothes.
* In ''WesternAnimation/{{Rugrats}}'', the babies believe Chuckie is allergic to Kimi since he begins to sneeze whenever she's near him or passes by him. Fearing that the adults would get rid of her if they find out, they try to keep him away from Kimi. It later turned out that Kimi had a bunch of dandelions in her diaper which she was planning to give to Chuckie as a gift.
* In ''[[https://archiveofourown.org/works/35402485/chapters/88242349?view_adult=true Sick]]'', [[Film/Ghostbusters1984 Egon]] thinks he is allergic to Ray's clothes or detergent, but actually [[UnknowinglyInLove he has a crush on him.]]
* In the ''WesternAnimation/SpongeBobSquarepants'' episode "Unreal Estate," Squidward purposefully evokes this trope by filling [=SpongeBob's=] foghorn alarm clock with [[PepperSneeze pepper]] to make him sneeze nonstop and think he's allergic to his pineapple house, forcing him to move away.
* In an old ''ComicBook/SupermansPalJimmyOlsen'' comic, Jimmy notices a funny ticking sound whenever he's around Superman, which he thinks is his heart. He concludes he has an allergy to the Man of Steel and must stay away until he can find a way out of it, or he risks death by heart attack. He eventually figures out that it was his signal watch, which malfunctioned and ticked whenever it was around gold.
* The ''Series/{{Swinging}}'' episode "The Big Sneeze" is about Augustus suddenly sneezing constantly and thinking he might have an allergy to his daughter Rosy. It's actually an allergic reaction to a [[FlowersOfFemininity flower decoration Rosy is wearing in her hair]].
* In the ''Series/WimziesHouse'' episode "Achoo!" (a.k.a. "Nothing to Sneeze At"), Wimzie thinks she's allergic first to her grandma Yaya, and then to her father Rousso, but it turns out that she's really allergic to bell peppers.

[[folder: '''The detection allergy''' \\
"We need to find / be warned about a certain creature, and happen to be allergic to it!"]]

* The Eighth Doctor does this in the [[AudioPlay/BigFinishDoctorWho Big Finish]] ''Series/DoctorWho'' episode "Caerdroia", where it turns out that the exact time portals they're looking for give him time sickness just by standing next to them. His two companions delight in dragging him around the field as a living detector device while he struggles to keep standing up.
* One ''WesternAnimation/DonaldDuck'' comic has Donald receive 1 million dollars from a stranger, but when he uses some of it to pay off a debt to [[ComicBook/DisneyDucksComicUniverse Scrooge McDuck]], Scrooge immediately starts sneezing; it turns out the money is counterfeit, and Scrooge is allergic to counterfeit money.
* In the ''Literature/{{Goosebumps}}'' book ''I Am Your Evil Twin'', the main character uses his peanut allergy to distinguish himself from his evil clone--since they aren't sure how allergies work, he supposes that the clone might not have it. (After the climactic test, though, it turns out that the clone swapped out the test food for one that he wasn't allergic to, and then made himself throw up so everyone would think he was the real thing.)
* In the 1998 ''Film/{{Madeline}}'' film, Miss Clavel is allergic to dogs. Her own sneezing alerts her to the fact that the girls have broken the "no pets" rule and are hiding a dog in the school. Still, she lets them keep Genevieve as long as they keep her outside.
* In ''WesternAnimation/MiraculousLadybug'', Adrien/Chat Noir is allergic to feathers, which comes up in the episode where he and Ladybug have to fight a pigeon-themed akuma.
* In the ''Series/MurderSheWrote'' episode "[[Recap/MurderSheWroteS3E12CrossedUp Crossed Up]]", Jessica originally can't figure out which of the relatives put out the hit, because none of them have raspy voices. However, then the family appears on TV. [[spoiler: Gordon Rogers]] is holding [[spoiler: his wife's new]] Persian cat, to which they're allergic. The allergies roughen their voice, creating the raspiness Jessica heard.
* ''Series/{{NCIS}}'': [=McGee=] is allergic to a cologne of a suspect, later a body turns up that causes [=McGee=] to sneeze.
* Taken Up to Eleven by Ruby "Pufferfish" Peet in ''Literature/{{NERDS}}''. This child's allergies are so severe that they actually go off whenever she's exposed to things such as danger, threats, dishonesty, and betrayal. Making her a human danger detector.
* In ''WesternAnimation/ScoobyDooMysteryIncorporated'', Daphne's allergies have been the key to major clues at least twice. In episode 2, the fake gator belts setting off her allergy to imitation animal products lets the kids crack the counterfeit gator ring, while in episode 4, her lack of a reaction to the Man-Crab despite a severe seafood allergy clues Velma in to the fact that the Man-Crab isn't really a crab.
* ''WesternAnimation/TheSecretOfNIMH'': Jeremy's cat allergy, warning them that the farmer's cat is near and distracting him when Dragon does arrive.
* ''VisualNovel/{{Snatcher}}'' uses a Detection Allergy - the eponymous robots release a masking agent called SNOW-9 which is similar to pollen, causing people (including the protagonist) to sneeze when they're in the area.
* In ''WesternAnimation/StormHawks'', Junko is allergic to Murk Raiders and Sky Sharks, both of which cause him to release Sneezes of Doom.
* ''WesternAnimation/TeenTitans'': Starfire's allergy to a metal used in a certain bomb (and lots of other stuff)
* In ''WesternAnimation/TheTick'' episode "Bloomsday" Arthur uses his hayfever to track down the missing 400 year bloom.
* In the ''Literature/WarriorCats'' novella ''Pebbleshine's Kits'', Pebbleshine hides in a car, hoping it'll bring her back to where she lost her Clan, but is detected by the humans who own it when their child starts sneezing uncontrollably - turns out she's allergic to cats.

[[folder:'''The assassin allergy''' \\
"He was killed with the previously unknown allergy to a X!"]]

* In the ''Literature/BenjaminJanuary'' series, one book has a murderer poison his victim's dinner with something he was violently allergic to. Since there's no widespread awareness that food allergies even exist, much less that the victim had one, nobody thinks he could have been poisoned by something that everyone else ate.
* ''Black Widow''. BlackWidow Catharine Petersen marries men and murders them by giving them a substance to which they have a lethal allergy.
* ''WesternAnimation/TheBotsMaster'' Ziv Zulander and his sister almost fell victims to this trope.
* ''Webcomic/CryptsAndCantrips'': Turns out [[spoiler: The king]] is allergic to a posion that should have taken weeks or month to kill him, so instead he dies within hours.
* ''Literature/TheDaVinciCode'': [[spoiler: Leigh]] disposes of a butler who knew too much and was allergic to peanuts by putting peanut dust in his wine.
* The ''WesternAnimation/{{Duckman}}'' episode "Days of Whining and Neurosis" features a [[PopGoesTheHuman grotesque murder]] by lactose intolerance.
* In the last book of the ''Literature/EmpireOfTheAnts'' trilogy, the protagonist's uncle dies near the secret base because he turns out to be allergic to their sedative.
* ''Series/HouseMd'': In Season 5, House subconsciously attempts to kill [[spoiler:Chase]] with his strawberry allergy by hiring a stripper to the latter's bachelor party who uses strawberry body butter. House only realizes what he did when he learns of [[spoiler:Chase]]'s an anaphylactic shock and deems his hallucination of [[spoiler:Amber]] dangerous.
* In the ''Series/MidsomerMurders'' episode "Red in Tooth & Claw", someone places rabbit fur in the ducts of Cleo Langton's car. Turning on the A.C. system with the windows closed triggers her allergy to rabbits, and someone had removed the allergy medication from her purse, so she dies by respiratory failure.
* One episode of ''Series/MurdochMysteries'' has the victim of the week, who was allergic to peanuts, die when the rim of the cup they were drinking out of was coated with peanut oil. Another has the victim killed ''in jail'' by replacing the cook's vegetable oil with soya oil, which had no effect on the other prisoners.
* In ''Literature/OneOfUsIsLying'', Simon is killed with peanut oil, which he is allergic to, in his water.
* In ''Film/TheOccupant'', Tomas is established to be extremely allergic to peanuts. [[spoiler:Javier injects peanut extract into a can of pepper spray and then engineers the situation for Javier to be sprayed, his death covered up as a bad reaction to the pepper spray]].
* In ''Fanfic/WhereTalentGoesToDie'', the second victim is killed by ingesting peanuts, to which he is allergic. The second motive had made the students aware of one another's weaknesses, and after the students learn about his allergy, they must discover who knew about it before the murder and had the opportunity to poison him.

[[folder:'''The manipulation allergy''' \\
"I have your allergen, you will obey me!"]]

* Just about all the husbands on ''Series/DesperateHousewives'' have suffered from some convenient allergy which their wives use to manipulate in some way, which is then never mentioned again. Especially obvious in the case of Carlos, who was allergic to eggs for one episode, despite this never inhibiting anything he's eaten in previous and later episodes. You could FanWank that all his food is made with egg substitutes and it's just never mentioned, but what all those times he's shown eating scrambled eggs for breakfast?
* In ''WesternAnimation/TheSimpsons'', Bart finds out about Principal Skinner's allergy (peanuts) and uses it to manipulate him; later it turns out Bart has a similar allergy (shrimp) and violence ensues. This is not mentioned elsewhere, and Bart has had no problem eating at the Frying Dutchman seafood restaurant.
* ''Series/StargateAtlantis'': Rodney [=McKay=] is mortally allergic to citrus. In "The Pegasus Project", before sending [=McKay=] off to help [[Series/StargateSG1 SG-1]] on a mission, Sheppard gives Mitchell a lemon in case [=McKay=] gets out of hand. Later, when [=McKay=] claims that the mission is impossible, the lemon makes a reappearance.
-->'''[=McKay=]:''' What stories? What have you heard?\\
'''Mitchell:''' Well, for starters, that you didn't know the meaning of the word "impossible"... and that under threat of impending death, you could work absolute miracles.\\
'''[=McKay=]:''' Yes, well it's all true, but I'm not under the threat of impending death, and I don't have a--\\
(''Mitchell pulls out the lemon and holds it up to Rodney's face'')\\
'''[=McKay=]:''' ...Well, I'll see what I can come up with, then.
* ''Film/LoveInTheVilla'': Charlie is deathly allergic to cats, which is unfortunate for him as the piazza is full of them. Julie lures them into his bedroom in an attempt to get him to leave the villa.

----
!!Other Examples:

[[AC:{{Anime}} & {{Manga}}]]
* An episode of the first ''LightNovel/DirtyPair'' TV series had as the antagonist a man allergic to women. Mostly played for laughs[[spoiler:, and eventually revealed to be psychosomatic.]]
* In episode of ''LightNovel/LoveChunibyoAndOtherDelusions'', Touka is allergic to cats, so when her younger sister Rikka brings one home, she requests Yuuta to help her get rid of it. When Yuuta expresses reluctance, she [[{{Blackmail}} presents him an audio clip]] of [[OldShame one of his rants as the "Dark Flame Master"]].
* Anime gives us an example of allergy as code phrase: in ''Anime/WeissKreuz Verbrechen & Strafe'', one of the operatives signals her team that something is amiss by referring to a flower allergy she doesn't actually have. (They know she's faking because the other operatives are all florists.)

[[AC:AsianAnimation]]
* ''Animation/HappyHeroes'':
** In one episode, an assassin cat tries to kill Careful S. but gets mistaken to be a stray cat. Careful S. takes care of him despite being allergic to cat fur. However, this allergy highlights the irony with Careful S' appearance (he looks like a black cat).
** In one episode of Season 11, Moondance is shown to have an allergic reaction to mango when she eats Sweet S.'s pudding, which contains it.
* In ''Animation/PleasantGoatAndBigBigWolf: Mighty Little Defenders'' episode 36, Wolnie is allergic to dogs, which causes problems since her husband Wolffy has been turned into a dog and can't go near her without causing her to sneeze.

[[AC:Comic Books]]
* In ''Ultimate Hangout'', based on ''WesternAnimation/TheLoudHouse'', Clyde is allergic to geese and uses goose feathers to make himself sneeze and get his fathers' attention.

[[AC:FanWorks]]
* ''Fanfic/TheBoltChronicles'': Unlike Mittens’s owner Jack, his neighbor Darnell likes the cat, but cannot provide an alternative home for her because he has cat allergies in “The Survivor.”
* In ''Fanfic/TheCliff'', a certain allergy saves the day. Gibich plants two rows of poplars, and soon it turns out Gutrune and [[spoiler:Fafner]] are horribly allergic to poplar fluff. [[spoiler:Fafner's sneeze ends up blowing the RingOfPower into the Rhine to its rightful owners, effectively solving the ''key problem'' of both the canon and the fanfic, while Gutrune’s allergy attack prompts Brünnhilde to realize what the matter with the dragon is]].
* In ''Fanfic/FirstTrySeries'', the ''whole'' plot is set in motion due an exam proctor's unfortunate allergy to peanuts. The exam proctor had to be replaced and the replacement tested Manga/{{Naruto}}, which allowed him to pass on the [[TitleDrop first try]].
* Neither Cameron nor Foreman can eat a certain dessert in the ''Series/{{House}}'' fanfic "Inferno" because she's allergic to chocolate and he's allergic to pecans, and it contains both.
* A few ''WesternAnimation/MiraculousLadybug'' fics bring up Adrien/Chat Noir's allergy to feathers when the Peacock kwami Duusu or his holder is involved.
** ''Fanfic/BackToUs'' first brings it up during his first encounter with the Peacock Miraculous holder Pavone, and again when he goes into a sneezing fit in Felix's car -- when Bridgette asks if Felix has a pet bird, he replies, "Something like that."
** ''[[http://archiveofourown.org/works/7658497/ A Declaration Of Love]]'' turns it into a running gag, because the Peacock holder in this universe is Marinette. Though when Adrien is forced to use the Peacock Miraculous in her place, he's explicitly not allergic to himself.
* ''Fanfic/TheRigelBlackChronicles'': The sleeping sickness is bad enough, with a large portion of the student body falling into magical comas, but then it turns out that [[spoiler:Draco Malfoy]] is allergic to an ingredient in the potions used to keep the victims alive and stable, forcing Harry to find another solution in a hurry.
* In ''FanFic/ThisBites'', eating biscuits gives Cross an instantaneous and horrible case of diarrhea. It's unclear why, and it's not much of a plot point; it's barely even a RunningGag.
* Subverted in ''[[https://www.fanfiction.net/s/12573127/1/Under-the-weather Under the Weather]]'' (based on ''Film/Ghostbusters1984'') where first Egon, then Janine, think they have allergies when they really have colds.

[[AC:{{Film}}]]
* ''Film/AddictedToLove'': Meg hides crushed strawberries under her ex's pillow, causing him to break out in an embarrassing skin rash and sabotaging his modeling career.
* In ''WesternAnimation/TheBoxtrolls'', Archibald's severe lactose intolerance (he swells up from a tiny sliver of ''extra mild'' Cheddar) is part of what prevents him from joining the White Hats [[spoiler:and eventually leads to his KarmicDeath]].
* In ''Film/TheIncident2014'', two parallel allergies, one to fruit juice and one to bees, drive the intersecting time loops.
* In ''Film/TheManWhoKnewTooLittle'', Wallace complains several times about Boris "The Butcher" wearing Old Spice; his violent sniffling and sneezing actually helps him to escape Boris' custody at one point. At the very end, we learn that it wasn't Old Spice causing Wallace's reactions--it was an otherwise-undetectable Amazonian arrow-frog toxin.
* In ''Film/Molly1983'', Aunt Jenny is allergic to dogs, so Maxie has Molly spend the night at a barber shop.
* In ''Film/PeterRabbit'', Thomas [=McGregor=] is allergic to blackberries. Later the rabbits pelt him with blackberries, eventually landing one directly in his mouth, but he gives himself an injection.
* In ''WesternAnimation/PoundPuppiesAndTheLegendOfBigPaw'', the main villain Marvin [=McNasty=] happens to be allergic to cats. Cooler eventually takes advantage of this when [=McNasty=] orders his henchmen Lumpy and Bones to take away the Pound Purries Hairball and Charlemange by disguising himself as cat so he'd be taken out of [=McNasty=]'s house with the Pound Purries.
* ''Film/TheSmurfs2'':
** When Grandpa Victor gives the children at a party corn dogs, one of the children turns out to be allergic to the peanut oil they were fried in.
** One scene reveals that Patrick is allergic to feathers, but when he was a kid, Victor lied that ''he'' was to take the fall for getting rid of the family's parrot Zeus.
* ''Film/TurkeyHollow'': Annie is allergic to feathers. When she and Tim get kidnapped and held in a small building full of live turkeys, her father and great aunt need to get her out as soon as possible.

[[AC:{{Literature}}]]
* ''Literature/{{Achoo}}'': The reason Suzy-Sue sneezed and started the plot was because she was allergic to a flower she sniffed. The dog also appears to have hay fever as he's seen with a runny nose but otherwise appears fine.
* ''Literature/AmeliaBedelia'': In one of the prequel books, the young Amelia finds a lost cat. She wants to keep her, but Mrs. Bedelia is allergic to cats, so she can't.
* In one ''Angela Nicely'' book (a spinoff of ''Literature/DirtyBertie''), Angela mistakes her teacher's red eyes, which are actually due to hay fever, as a sign she's been [[MistakenForBrooding crying]], and tries to cheer her up by [[StudentsPlayingMatchmaker hooking her up with Mr. Weakly]].
* Rachel ends up with an alien allergy to crocodile DNA in one ''{{Literature/Animorphs}}'' book. She morphs out of control, which is the equivalent of a sneeze, according to Ax, and has to deal with the allergy until she burps up the DNA-in the form of a whole crocodile.
* ''Literature/DiaryOfAWimpyKid'': Greg has told two lies about allergies:
** In the first book, he convinces bullies not to force him to eat an expired slice of cheese by lying that he's allergic to dairy.
** In "The Ugly Truth", he lies that Mnany is allergic to peaches to try to convince the advertisers of peach ice cream to make him their mascot instead of Manny.
* In ''Eppie the Elephant Who was Allergic to Peanuts'', Eppie has to ask her friends not to sit next to her at school if they're having peanuts since she's allergic to them. Her friends are notably [[StockAnimalDiet surprised that an elephant could be allergic to peanuts]].
* ''Literature/JaineAustenMysteries'': In ''The PMS Murder'', Marybeth Olsen is killed via someone taking advantage of her peanut allergy.
* ''Literature/TheRavenCycle'': Gansey is severely allergic to bees, hornets, and wasps. His obsession with Glendower, which the series is based around, started after he was stung to death by hornets as a child, only to live because [[spoiler: Noah was dying on the ley line at the same time]]. He considers his [=Epipen=] to be largely useless as it would not be enough to save him even after a single sting.
* ''Literature/RevengeOfTheSith:'' While over at Padmé's apartment, Anakin notes a particular type of broth sitting around, which gets him suspicious (well, [[TheParanoiac more suspicious]]) since Padmé says Obi-Wan's been over recently, but Anakin knows Obi-Wan is so allergic to that specific broth he once nearly caused an interstellar incident. She has, in fact, been talking with other senators.
* In Creator/StephenKing's Franchise/SherlockHolmes story ''[[Literature/NightmaresAndDreamscapes The Doctor's Case]]'', the reason Watson is the one to solve the case is that Holmes is seriously impaired by two factors: there are ten cats in the house the case is in, and Holmes is allergic to cats. It really doesn't help that one of the cats becomes very fond of Holmes immediately and gets snuggly.
* ''Literature/ASickDayForAmosMcGee'': The rhinoceros has seasonal allergies, so he has a runny nose, which Amos takes it upon himself to wipe.
* What started the plot of the fourth ''Literature/TanteiTeamKZJikenNote'', ''The Egg Hamburg Steak Knows'', was an allergy that causes a breakup but hardly "the relationship hitch allergy." [[HotBlooded Wakatake]] woke up on Friday and found his face covered with allergy hives, which obviously is not in a state to attend the date later that day. But the unnamed girlfriend decided to break up instead without even asking why he couldn't attend. (The bulk of the novel is about [[AmateurSleuth investigating]] how [[TamperingWithFoodAndDrink there could be pork in a egg burger steak supposedly made with 100% beef, and who put it there]]).

[[AC:LiveActionTV]]

* In ''Series/DumbosCircus'', Dumbo is allergic to flowers. Since he's not a baby anymore in this series, but an almost full-grown elephant, his allergy results in frequent [[SneezeOfDoom Sneezes of Doom]] that blow things around or knock them down.

[[AC: VideoGames]]

[[AC: VisualNovels]]

[[AC: {{Webcomics}}]]

[[AC:WebOriginal]]
* In Creator/SamAndMickey's ''The Barbie Cooking Show'' episode 2, Barbie needs to find a new co-host after Chelsea's allergy to almonds lands her in the ICU after handling the first ingredient of Barbie's red velvet cake recipe - almond meal flour.
* In ''WebVideo/DragonBallAbridged'', turns out Goku is allergic to grapes. When Future Trunks gives Goku his cholesterol medication, he has to be convinced by Trunks that it's actually bacon-flavored because it was grapes and he hates grapes. Turns out he's so allergic to them, he turns purple and starts ''sweating'' purple.

* ''WebAnimation/RWBYChibi''’s Battle of the Bands arc gives Neptune Vasilias a latex allergy that causes him to start swelling up whenever he touches Jaune’s Smooch-inspired [[ItMakesSenseInContext latex face paint]].

[[AC:WesternAnimation]]

* In the ''WesternAnimation/DonkeyHodie'' episode "Growing the Ungrowdenia'', we learn that Clyde can't be by flowers because he is allergic to them. This, among other problems, causes Donkey to try to ungrow the titular flower.