About 1% to 5% of the total population has food allergies. The prevalence of fish allergy in westernized countries ranges from 0.2% to 0.6%, whereas in Asian countries where fish consumption is higher, fish allergy may affect up to 2.3% of the population. As consumption of seafood is increasing in western countries because of its high nutritive value and its beneficial health effect, allergic reactions to fish may increase as well.
Most fish allergic patients usually react to multiple fish species, because they are mainly sensitized to parvalbumin, the major fish allergen, that shares sequence identities of 61% to 93% between species.
Fish allergy is considered a persistent and severe allergy that does not tend to disappear with age, and therefore affects children and adults. The symptoms of fish allergy range from mild oral itching to potentially severe reactions, even life-threatening, as anaphylaxis. The organs most frequently involved are the oral cavity, the skin and the gastrointestinal tract. Patients can also experience allergic reactions by skin contact and by inhalation of fish steam when cooking. Fish is also a cause of occupational allergy.
Nowadays, the only available treatment is to strictly avoid the ingestion of fish and to have rescue medication in case of an accidental ingestion, including self-injectable adrenaline for those at risk of anaphylaxis. As a result, patients and their families feel stress and anxiety about possible reactions and their quality of life is reduced. There is therefore a need for safe and effective immunotherapy for fish allergy. This unmet need is currently under development within the EU funded project FAST that aims to develop fish specific immunotherapy by the application of hypoallergenic recombinant parvalbumin.