Contact urticaria caused by heat‐sensitive raw fish allergens

Abstract

Patients allergic to fish usually present with skin reactions after handling raw fish. Less frequently, these reactions are seen without symptoms after oral intake, often in chefs and food handlers. We have attempted to explain the skin selectivity of such reactions in a 36-year-old woman with contact urticaria after handling raw fish. We obtained aqueous extracts of raw and cooked fish (sole and hake) for in vivo (prick test) and in vitro (SDS-PAGE, IgE Immunoblot) tests. Prick-by-prick test, 20-min closed patch test, rub test with fresh and cooked fish (sole, hake and cod) and specific IgE (CAP-system) to sole, cod and hake were performed. The strength of positive reaction to raw fish was greater than to cooked fish on both prick and prick-by-prick testing. Rub tests showed positive responses only to raw fish. Specific IgEs to sole (45 KU/l), hake (66.9 KU/l) and cod (18.7 KU/l) were obtained. IgE immunoblot recognized 3 antigens of 25, 48, 56 kDa in raw sole and 1 of 42 kDa in raw hake extracts. No IgE binding was observed with the cooked extracts or control sera. Our findings strongly suggest a Type-I hypersensitivity to fish. Immunoblot analyses demonstrated a loss of specific IgE binding to cooked extracts. We have reported a case of contact urticaria caused by heat-sensitive raw-fish allergens in a patient who probably became sensitized via the cutaneous route.

Identification of Parvalbumin and Two New Thermolabile Major Allergens of Thunnus tonggol Using a Proteomics Approach

“…The raw extract contains 26 protein fractions, generally similar to the protein profile of raw yellowtail tuna [28,33], whereas the boiled extract has only 9 protein bands, probably due to denaturation of thermolabile proteins of 16-25 and 40-90 kDa. This protein pattern is also in accordance with other studies which reported thermolabile proteins between 20-100 [40] and 40-90 kDa [41] in multiple fish species. Allergic reactions to fish most commonly occur upon ingestion of cooked fish [6,8], but it can also be triggered by raw fish, particularly after direct contact with the raw fish, ingestion of raw or undercooked fish, or inhalation of fish odours or fumes, as proven by other researchers [41,42,43].…”

“…This protein pattern is also in accordance with other studies which reported thermolabile proteins between 20-100 [40] and 40-90 kDa [41] in multiple fish species. Allergic reactions to fish most commonly occur upon ingestion of cooked fish [6,8], but it can also be triggered by raw fish, particularly after direct contact with the raw fish, ingestion of raw or undercooked fish, or inhalation of fish odours or fumes, as proven by other researchers [41,42,43]. It was reported that almost 10% of patients with seafood allergy including fish have more severe reactions caused by inhalation or skin contact than by ingestion [44].…”

“…Initially, seafood allergens are often reported as heat-stable proteins and therefore resist the effect of cooking, processing or digestive processes [17]. However, other findings have confirmed the presence of thermolabile allergenic proteins in multiple species of fish [28,32,41], and canned tuna is considered the least-allergenic form of fish [33]. Hence, allergenicity of the thermolabile proteins seems to be reduced by heat (boiling, frying or grilling) [40,44], as well as by drying, salting, smoking and chemical processing [33].…”

Identification and characterization of a new IgE-binding protein in mackerel (Scomber japonicus) by MALDI-TOF-MS

“…All these allergens belong to parvalbumins, which are calcium-binding sarcoplasmic proteins with a molecular mass of about 12 kDa. These proteins were identified as the major cross-reactive allergens among various fish species (Bernhisel-Broadbent et al, 1992;Hamada et al, 2001;Porcel et al, 2001;Rosmilah et al, 2005 and.…”

Contact urticaria by angler fish

“…It has been reported that fish antigens of >40 kDa molecular weight are more heat‐sensitive (4, 5), and are probably responsible for isolated contact urticaria without allergic symptoms after oral intake (6). These allergens are not well characterized.…”