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 cause you to have more serious reactions.
Parvalbumins are very stable proteins, so able to cause reactions when cooked or as vapour during cooking (but food is thought to be 20-60% lower in parvalbumins when cooked). It 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 enolases, aldolases, collagen and gelatin.
There is no information on syndromes associated with fish allergy.
Occasionally there can be cross reactivity between fish and products containing gelatin.
Other foods containing aldolase and enolase proteins include chicken, cod, catfish, salmon and tuna.
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
Articles and Journals
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
Important variations in parvalbumin content in common fish species: a factor possibly contributing to variable allergenicity, 2010
IgE antibody to fish gelatin (type I collagen) in patients with fish allergy, 2000
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