Type-I reactions to commercial fish in non-exposed individuals.

The frequency of type-I reactions (contact urticaria) to plaice, whiting, common dab, witch, codfish, Norwegian haddock, herring and halibut has been examined in 26 individuals; 23 of these carried through all the investigations. 65% of the volunteers had a positive scratch patch test to one or more species of fish. All 20 min closed patch tests were negative. 5 of the volunteers were atopics. They showed about twice as many positive scratch patch tests when compared to the non-atopics. The investigation shows that the "fish allergen" is destroyed by cooking but not by freezing. The possibility of common and specific fish allergens is discussed.