Fish Allergy: Symptoms, Diagnosis and Living Fish-Free

Symptoms, Diagnosis and Learning to Live Fish-Free

Fish allergy tends to be a lifelong allergy, with about 40% of people with fish allergy experiencing their first reaction as an adult. The most common kinds of finned fish causing an allergic reaction are salmon, tuna, and halibut, although other ​fish such as Pollock, cod, snapper and eel are also common.

Fish on ice
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More than half of individuals who are allergic to one finned fish will be allergic to another, so those with fish allergy are usually advised to avoid all fish. However, it's possible to test for a specific fish allergy.

Fish allergies are similar to shellfish allergies in that they are more likely than many food allergies to start during adulthood and less likely than other allergies to be outgrown. While fish is easier than many other allergens to avoid, a fish allergy is often quite severe.


Fish allergy is linked to an increased risk of severe asthma in adult patients. Fish has also been linked with oral allergy syndrome (in which the mouth itches or tingles after eating an allergen, usually fruit or vegetables) in people with occupational contact with fish.

The greatest risk from fish allergies is anaphylaxis, a severe systemic reaction in which the body releases large amounts of histamine, causing tissues throughout the body to swell. This can cause life-threatening breathing, cardiac, and gastrointestinal symptoms. Anyone with a fish allergy should carry medication prescribed by their healthcare provider at all times.


Fish allergy is usually diagnosed by an allergist after a medical history, physical examination, and food allergy testing are performed. Your healthcare provider will talk to you about your symptoms and perform testing to determine if you're truly allergic to fish, or if you might be reacting to something else.

One allergy that may masquerade as a fish allergy is an allergy to a fish parasite called Anisakis simplex. This parasite is considered a major allergen and, like fish allergies, can cause severe allergic reactions including anaphylactic shock.

If you have a severe allergic reaction after eating fish but testing is negative or inconclusive, consider asking your allergist to test you for an allergy to this parasite. Anisakis larvae can be killed by freezing or cooking, but they can still trigger allergies after being killed, so people with Anisakis allergies should avoid fish and shellfish altogether.


The treatment for fish allergy is the elimination of fish from the diet. Since this allergy tends to be lifelong (meaning you don't outgrow it), you'll probably have to stay away from fish permanently.

There is high allergic cross-reactivity among different types of fish, meaning that people with allergies to one type of fish are likely to have (or to develop) allergies to other types of finned fish. This is due to a protein called parvalbumin which is present in many fish. For this reason, most people with an allergy to one fish are advised to avoid all fish (including eel and shark).

Still, some fish, especially tuna and mackerel, are considered less allergenic than others. If you would like to include some fish in your diet, ask your allergist about arranging additional allergen testing to assess what fish might be safe for you.

How to Avoid Fish

As one of the most common allergens in the United States, fish is covered under the Food Allergy Labeling and Consumer Protection Act (FALCPA). This requires that manufacturers label the presence of fish in clear language on food labels, either in the list of ingredients or following the word "contains" after the ingredient list.

Fish is not a particularly common hidden ingredient and generally appears as its own species (e.g., "Contains: salmon") in ingredient lists. People with fish allergies should know how to read an ingredients label and learn the names of many different types of fish for maximum safety.

There are many species of finned fish, so a complete list of fish to avoid is not possible for this article. However, some of the most common types of fish include:

  • Anchovies
  • Bass
  • Catfish
  • Cod
  • Flounder
  • Grouper
  • Haddock
  • Hake
  • Halibut
  • Herring
  • Mahi Mahi 
  • Perch
  • Pike
  • Pollock
  • Salmon
  • Scrod
  • Swordfish
  • Sole
  • Snapper
  • Tilapia
  • Trout
  • Tuna

Foods Commonly Containing Fish

You'll also need to steer clear of foods that contain fish as an ingredient (always read ingredient labels to be certain). These foods may include:

  • Caesar salad dressing
  • Worcestershire sauce
  • Ceviche (fish or shellfish "cooked" in an acidic citrus marinade)
  • Caviar
  • Gelatin (when made from the skin and bone of fish)
  • Cioppino (a fish stew)
  • Nam pla (Thai fish sauce)
  • Bouillabaisse (a fish stew)
  • Fumet (fish stock)
  • Surimi (an imitation or artificial fish or shellfish)
  • Pissaladière (an open tart that looks like pizza; made with anchovies)
  • Omega-3 supplements (if you would like to take these, look for vegan varieties made from flaxseed or other plant-derived oils)
  • Caponata (eggplant relish)

You may not realize that isinglass, a type of gelatin made from the air bladders of certain fish, is mostly collagen and may be commercially used to clarify beer or wine. Those with fish allergy and risk for anaphylaxis should avoid wine and beers clarified with isinglass. You'll need to contact manufacturers to find out if individual products are safe since alcoholic beverages don't need to list ingredients on their labels.

Dining out With Fish Allergy

You can tailor your choice of restaurant to lessen your risk. Seafood restaurants, sushi bars, and ethnic restaurants such as Thai establishments are high risks for cross-contamination due to the close proximity of fish and non-fish items. Another source of potential cross-contamination is frying oil; if fish has been fried in oil, people with fish allergies should avoid eating any other food fried in the same oil.

There are recorded instances of inhalation reactions due to aerosolized fish proteins (fish proteins being released into the air upon steam cooking), so people with fish allergies should avoid hibachi-style communal grill restaurants if fish is on the menu.

A Word From Verywell

Fish is an easier allergen to avoid than many of the other "big eight" allergens. It is less pervasive in the Western diet than wheat, soy, or dairy, which are much harder to avoid.

That's not to say that living with a fish allergy is easy. The major challenges are avoiding high-risk situations for contact with fish and managing the risk of severe asthma (where applicable) and anaphylaxis. Reading labels for fish is reasonably simple in grocery stores. Communication in restaurants, however, is vital; higher-end restaurants, especially, may use small amounts of fish to flavor dishes that may not indicate the presence of fish on the menu. 

Managing asthma and anaphylaxis risk both depend on communication with your healthcare provider and keeping any prescribed medication close at hand: a rescue inhaler, in the case of asthma, and injectable epinephrine in the case of anaphylaxis.

If you have concerns about keeping fish out of your diet, consider asking your healthcare provider to refer you to a dietitian who is skilled in managing food allergies. A dietitian can help you revise your diet and learn where fish can hide in restaurant meals.

10 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Gupta RS, Warren CM, Smith BM, et al. Prevalence and Severity of Food Allergies Among US AdultsJAMA Netw Open. 2019;2(1):e185630. doi:10.1001/jamanetworkopen.2018.5630

  2. Foong RX, du Toit G, Fox AT. Asthma, Food Allergy, and How They Relate to Each OtherFront Pediatr. 2017;5:89. doi:10.3389/fped.2017.00089

  3. Commins SP. Outpatient Emergencies: AnaphylaxisMed Clin North Am. 2017;101(3):521–536. doi:10.1016/j.mcna.2016.12.003

  4. Mazzucco W, Raia DD, Marotta C, et al. Anisakis sensitization in different population groups and public health impact: A systematic reviewPLoS One. 2018;13(9):e0203671. doi:10.1371/journal.pone.0203671

  5. Kuehn A, Swoboda I, Arumugam K, Hilger C, Hentges F. Fish allergens at a glance: variable allergenicity of parvalbumins, the major fish allergens. Front Immunol. 2014;5:179. doi:10.3389/fimmu.2014.00179

  6. D'Auria E, Abrahams M, Zuccotti GV, Venter C. Personalized Nutrition Approach in Food Allergy: Is It Prime Time Yet?Nutrients. 2019;11(2):359.doi:10.3390/nu11020359

  7. Goyal R, Deshmukh N. Food label reading: Read before you eatJ Educ Health Promot. 2018;7:56. doi:10.4103/jehp.jehp_35_17

  8. Hickman D, Sims TJ, Miles CA, Bailey AJ, De mari M, Koopmans M. Isinglass/collagen: denaturation and functionality. J Biotechnol. 2000;79(3):245-57. doi:10.1016/s0168-1656(00)00241-8

  9. Seafood Health Facts: Making Smart Choices. Seafood Safety Overview | Seafood Health Facts.

  10. Ring J, Beyer K, Biedermann T, et al. Guideline for acute therapy and management of anaphylaxis: S2 Guideline of the German Society for Allergology and Clinical Immunology (DGAKI), the Association of German Allergologists (AeDA), the Society of Pediatric Allergy and Environmental Medicine (GPA), the German Academy of Allergology and Environmental Medicine (DAAU), the German Professional Association of Pediatricians (BVKJ), the Austrian Society for Allergology and Immunology (ÖGAI), the Swiss Society for Allergy and Immunology (SGAI), the German Society of Anaesthesiology and Intensive Care Medicine (DGAI), the German Society of Pharmacology (DGP), the German Society for Psychosomatic Medicine (DGPM), the German Working Group of Anaphylaxis Training and Education (AGATE) and the patient organization German Allergy and Asthma Association (DAAB)Allergo J Int. 2014;23(3):96–112. doi:10.1007/s40629-014-0009-1

Additional Reading

By Jill Castle, MS, RD
Jill Castle, MS, RD, is a childhood nutrition expert, published book author, consultant, and public speaker who helps parents nourish healthy kids.