The authors evaluated four different therapeutic protocols employing 80 adult patients with clinical symptoms (urticaria and/or angioedema) due to food ingestion. Thirty-seven patients were allergic. In these cases the diagnosis was made on the basis of simultaneous positivity of the following criteria: history, exclusion diet and challenge tests, positive prick tests, and a positive PRIST and RAST. The other 43 subjects were considered to have pseudo-allergic reactions (PSAR). The pharmacologic treatment was performed for 4 to 6 weeks and each patient had a free diet during the study. At the end of the treatment, both the patient and the allergist filled a score questionnaire concerning the clinical status in order to evaluate the clinical improvement. Our data indicate that anti-H1 antihistamines do not significantly differ from placebos, that oral cromolyn is more successful in food allergy than in PSAR patients (P less than .05), that ketotifen is helpful, and that the association of H1 and H2 anti-histamine drugs is even more effective. Finally, by considering the effect on the immune system exerted by these drugs, as recently demonstrated in our laboratory, a detailed balance of each therapeutic protocol is then analyzed.