An allergy or allergic reaction referred to a body's inappropriate immune response to various stimuli, usually proteins. These stimuli were called allergens. (VOY: "Tinker Tenor Doctor Spy")
The body's responses could be minimal, such as snoring, sneezing, or a runny nose, but could also include the more serious anaphylactic shock, even death. Allergies often had a genetic basis. They could be present from birth or could present themselves at any later point during a lifetime.
In the 23rd century, in the medical history section of Christopher Pike's personnel file, an allergic reaction was listed with other ailments he had suffered during his lifetime prior to 2257. (DIS: "Brother")
In 2258 of the alternate reality, James T. Kirk suffered an allergic reaction to the antidote for a virus carried by Melvaran mud fleas administered by Doctor Leonard McCoy. (Star Trek)
In 2369, Odo told Quark that "the something" in Jadzia Dax's eye was an allergic reaction to him. (DS9: "The Passenger")
Later that year Julian Bashir thought he had taken an allergic reaction to replicated antipasto and was hallucinating an affectionate Jadzia Dax. (DS9: "If Wishes Were Horses")
When Elim Garak made Odo a Bajoran Militia uniform in late 2372, he asked him if he was allergic to Inkarian wool. (DS9: "Broken Link")
Species allergies[]
- The inhabitants to Sirius IX were allergic to a love potion sold to them by Harry Mudd. (TAS: "Mudd's Passion")
- Humans were allergic to Ferengi blood pyrocytes. (TNG: "The Price")
- Joined Trill were extremely allergic to insect bites. The reaction caused by the insect's venom interfered with the biochemical connections between the host and symbiont. (DS9: "The Siege")
Individual allergies[]
- Henry Janeway was allergic to chocolate, preferring oatmeal cookies instead. (VOY: "11:59")
- Travis Mayweather was allergic to a pain medicine he was once given on Risa. (ENT: "Two Days and Two Nights")
- Malcolm Reed was allergic to bromelain, for which he took regular injections. He was also allergic to dust mites, oak pollen, and tropical grasses. (ENT: "Silent Enemy")
- Sylvia Tilly was allergic to polyester and viscoelastic polyurethane foam. (DIS: "Context Is for Kings")
- James T. Kirk was allergic to Retinax V, an eye medication. (Star Trek II: The Wrath of Khan)
- James T. Kirk was allergic to the vaccine for the Melvaran mud flea virus. (Star Trek)
- Wesley Crusher was allergic to metorapan, an analgesic medication. He was treated with bicaridine instead. (TNG: "The First Duty")
- Quark once stated he was "allergic to nature." (DS9: "The Jem'Hadar")
- Commander Zakarian was allergic to many things earning him the nickname "Old Sneezy". (VOY: "Caretaker")
- Jadzia Dax was allergic to icoberry juice – it made her spots itch – but she drank it anyway because she liked the taste. (DS9: "Let He Who Is Without Sin...")
- While undergoing hyper-evolution, Tom Paris had an allergic reaction to the water Neelix used for the coffee "Paris Delight". (VOY: "Threshold")
- Neelix, while he had ingested leola root in many forms, discovered his skin was allergic to leola ointment, a topical Talaxian homeopathy remedy for sunburn. It caused discoloration, swelling and blistering to the applied areas. (VOY: "Tsunkatse")
- B'eth was allergic to feathers, which caused her to suffer uncontrollable sneezing fits and eventually collapse. She had an inhaler to mitigate the effects. (LD: "Old Friends, New Planets")
- Carol Freeman was allergic to chocolate, revealed when Brad Boimler ran a simulation of the crew in the holodeck to prepare for his interview with her. (LD: "Crisis Point")