The key proteins associated with fish allergy are called Parvalbumins, they are found in most species of fish. They are found in different concentrations in different species of fish, if you are allergic to these proteins it can be difficult to tell which fish causes you to have more serious reactions.
Parvalbumins are very stable proteins with the ability to cause reactions when cooked or as vapour during cooking (but food is thought to be 20-60% lower in parvalbumins when cooked). The protein is found in high concentrations in the light muscle of fish rather than the dark muscle, so fish like cod and carp are higher in parvalbumin levels compared to swordfish and tuna which have lower levels as they have more dark muscle tissue.
Parvalbumin is the protein used for allergy testing, if you are negative to these tests then your allergy may be to less common proteins found in fish, namely tropomyosin, enolases, aldolases, collagen and gelatin.
Tropomyosin is a protein found in certain types of fish including tilapia, catfish and salmon.
Some fish contain enolase and aldolase proteins
. These are minor panallergens found in fish, chicken, rabbit and snake meat. They are heat stable so are allergens of note.
and high histamine often go hand in hand. Fresh fish is low in sulphites, but the amount increases in the fish as it is processed, canned or smoked. Sulphites are inorganic salts used in preservations and have the potential to cause symptoms of food intolerance to those sensitive to sulphites, this food intolerance is more common in asthmatics. An improvement in symptoms can be made with a change to a low sulphite diet.
Fish can be considered to be high in histamine
, so is not suitable for people following a low histamine diet. The amount of histamine starts to increase once caught, so improperly handled and refridgerated fish can cause what is called 'scromboid poisoning'. The symptoms of this are very similar to a severe allergic reaction, so are often confused.
Fish is a low FODMAP food. FODMAP stands for F
olyols. Foods high in FODMAPs can cause symptoms of food intolerance, affecting the gastro intestinal system and this can be mistaken for a true IgE food allergy.
You can read more about Food Intolerances
on the dedicated Food Intolerance Page.
There is currently no information on syndromes associated with fish allergy.
Occasionally there can be cross reactivity between fish and other products containing gelatin.
Other foods containing aldolase and enolase proteins include chicken, cod, catfish, salmon and tuna.
Other seafood which contains tropomyosin includes shrimp, prawns, crab, lobster, squid, oyster, snail and abalone.
NHS - Food Poisoning
Allergy UK - Fish & Seafood Allergy
Allergy UK - Histamine Intolerance
Science Daily - Different food fish can cause different allergies
Thermofisher Allergen Encyclopedia - Cod
Dermnet NZ - Scrombroid Fish Poisoning
Histamine Food List
Healthline - FODMAP Foods
Articles and Journals
Thermostable allergens in canned fish: Evaluating risks for fish allergy, 2023
IgE-mediated fish allergy in Singaporean children, 2023
A case of acute Food Protein-Induced Enterocolitis Syndrome (FPIES) to fish, turkey and duck, 2022
Comparative proteomics and in silico allergenicity of fresh and powdered skipjack tuna and Nile tilapia, 2022
The first reptilian allergen and major allergen for fish‐allergic patients: Crocodile β‐parvalbumin, 2022
Fish Allergy: Fishing for Novel Diagnostic and Therapeutic Options, 2022
IgE-Mediated Fish Allergy in Children, 2021
Tropomyosin: A panallergen that causes a worldwide allergic problem, 2021
Fish allergy tolerance 16 months after diagnosis, 2021
Fish muscle processing into seafood products reduces β-parvalbumin allergenicity, 2021
A case of pediatric anaphylaxis caused by gummy tablets containing fish collagen, 2020
Cross-reactivity in fish allergy: A double-blind, placebo-controlled food-challenge trial, 2017
Fish collagen is an important panallergen in the Japanese population, 2016
Allergy to fish collagen: Thermostability of collagen and IgE reactivity of patients’ sera with extracts of 11 species of bony and cartilaginous fish, 2016
Fish allergens at a glance: variable allergenicity of parvalbumins, the major fish allergens, 2014
Specific IgE to fish extracts does not predict allergy to specific species within an adult fish allergic population, 2014
Measuring parvalbumin levels in fish muscle tissue: relevance of muscle locations and storage conditions, 2012
Important variations in parvalbumin content in common fish species: a factor possibly contributing to variable allergenicity, 2010
Comparison of allergenicity and allergens between fish white and dark muscles, 2006
IgE antibody to fish gelatin (type I collagen) in patients with fish allergy, 2000
Let me know if you found any of these interesting or useful.
If you spot an article or research that you think is interesting you can message me or tag me on Facebook or Twitter - links at the bottom of the page.