Provocation tests with egg or milk antigens were performed on symptomatic patients or those who were skin prick test positive to these antigens. Skin test positive patients responded immediately in 12/13 to nasal, in 7/15 to buccal and in 5/15 to gastric provocation tests. An immediate gastric response was within 1 h. The threshold dose for a positive result showed that tissue sensitivity from greatest to least was in the order: skin, nasal, buccal and gastric. None of the skin test negative group responded to any of the provocation tests. The results, particularly the nasal provocation, validate the skin prick test as a sensitive measure of type I allergy to defined foods. The relative insensitivity of buccal and gastric mucosae may explain positive skin test responses in asymptomatic subjects.