Masked type I wheat allergy. Relation to exercise-induced anaphylaxis.

Six patients had type I hypersensitivity to wheat. Three cases were exercise-induced anaphylaxis to wheat, one was exercise-induced urticarial reaction to wheat (with angioedema), and the remaining two were exercise-accentuated urticarial reaction to wheat. Elimination of wheat from the diet completely cleared these symptoms. Allergens were prepared from wheat, gluten, gliadin, and glutenin by simple extraction and enzyme digestion, and these preparations were used in skin tests. The allergens obtained from gluten, gliadin, and glutenin by pepsin digestion were qualitatively different from wheat and gluten allergens obtained by simple extraction and were more related to exercise-induced anaphylaxis. Trypsin digestion showed no such effect and abolished all these allergens. These results indicate that wheat allergens are reinforced in the stomach and destroyed in the jejunum.