Immediate hypersensitivity in hand dermatitis. Role of food-contact dermatitis.

A patient had a chronic hand eczema, presumably as a manifestation of atopy. Treatment resistance appeared due to handling certain foods that produced burning and stinging in the chronically eczematous skin and not in otherwise normal skin. Selected tests for delayed hypersensitivity and for immediate hyper sensitivity on intact skin of the back produced negative results, but on chronically inflamed skin of the arm and back, application of the pertinent foods produced a wheal and flare response. On intact skin, scratch tests with the foods produced positive results. Intradermal tests with commercial antigens were negative. Avoidance of these foods, as contactants, led to resolution of the dermatitis. Reappraisal of the role of immediate-type hypersensitivity in chronic hand eczema is important.