Possible consequences of elimination diets in asymptomatic immediate hypersensitivity to fish.

The natural history of IgE antibodies to food without related symptoms is unknown. We have followed the progress of 7 children with various atopic diseases and asymptomatic immediate hypersensitivity to fish, treated with elimination diet in spite of full alimentary tolerance. During the diet period, between 24 and 113 months, all 7 patients presented immediate symptoms upon accidental exposure to or challenge tests with fish (skin symptoms in all 7 cases, digestive in 5, respiratory in 4, and anaphylaxis in 2), which differed from those related to atopic diseases previously present. The levels of fish-specific IgE (prick test, RAST) remained unchanged or were increased. These findings suggest that during elimination diet, and perhaps due to minimal and hidden contact with the allergen, the patients' degree of sensitization may increase, turning an asymptomatic into a symptomatic immediate hypersensitivity.