🐟Fish allergy
Fish allergy can start at any age, including in adults, and usually lasts for life. Reactions can be severe, so it is managed by avoiding fish completely — for some people, even the steam from cooking it.
🔬What it means
In a fish allergy the immune system reacts to fish proteins, mainly one called parvalbumin, which is similar in many species. That is why people allergic to one fish often react to others; an allergist can test which fish, if any, are safe for you.
Fish allergy is not the same as shellfish allergy. Crustaceans such as prawns and crab and molluscs such as mussels and squid contain different proteins and are separate allergens on labels. Some people are allergic to both, so ask your allergist before eating shellfish.
✅What you can eat
Everything that does not contain fish or traces of it: plain meat, eggs, dairy, grains, fruit, vegetables and pulses. Whether shellfish is safe depends on your own tests. Walnuts, flaxseed, chia and rapeseed oil provide omega-3 fats without fish (a different type from the omega-3 in fish).
🚫What to avoid
- 🐟Fish in any form: fresh, frozen, smoked, canned (tuna, sardines, anchovies), dried or salted fish, fish roe and caviar.
- 🥫Sauces and seasonings: fish sauce (nam pla, nuoc mam), Worcestershire sauce (usually made with anchovies), Caesar dressing, anchovy paste, dashi (made with bonito flakes).
- 🦀Surimi and crab sticks — made from white fish despite the name.
- 🍕Dishes where fish is common: sushi, paella, bouillabaisse and fish soups, fish cakes, kedgeree, puttanesca and pizza with anchovies, salade niçoise, tapenade (often with anchovies), many Thai and Vietnamese dishes, kimchi (often made with fish sauce).
- 💨Cooking vapour: steam and fumes from frying or boiling fish can cause a reaction in some people — take care in kitchens and at fish counters.
- 🍽️Cross-contact: shared fryers (chips are often fried in the same oil as fish), grills and sushi counters. Tell the staff about the allergy every time.
- 🏷️Labels: in the EU and UK fish must be highlighted in the ingredients. “May contain fish” means there is a risk of traces — most allergists advise avoiding these products.
⚠️What happens during a reaction
Symptoms usually start within minutes to two hours: itchy mouth, hives, redness, swelling of the lips or face, stomach pain, vomiting, sneezing or a runny nose.
A severe reaction — anaphylaxis — affects breathing or circulation: swelling of the tongue or throat, hoarse voice, wheezing, difficulty breathing, feeling faint, pale or clammy skin, collapse. It can develop fast and is life-threatening.
Fish allergy rarely goes away, so keep avoiding fish even after years without a reaction unless an allergist tests you. Spoiled fish can cause scombroid poisoning, which looks like an allergy; a doctor can tell them apart.
🚑When to get help urgently
If there are any signs of anaphylaxis, use an adrenaline auto-injector if you have one and call emergency services immediately, even if symptoms improve. Lie down with legs raised (or sit up if it is hard to breathe) and do not stand up suddenly. After any reaction, see a doctor about an allergy plan.
📱How Me Nutrition helps
Every dish in the app and on this site shows the major allergens of a typical recipe, including fish, and which ingredient contains them. Recipes differ and traces are not covered, so always check with whoever cooked the dish.
Dishes that contain it: 298
Sources
Written from the sources below; not reviewed by a doctor. Not medical advice. How we count →