Food allergy (FA) and food intolerance (FI) are complex syndromes caused by adverse reactions to foods. Since mucosal permeability of the digestive tract is often increased during this pathology, we evaluated the clinical efficacy of two different cytoprotective drugs in patients with urticaria-angioedema due to FA and FI. These drugs were pirenzepine, an anti-muscarinic (anti-MI) receptor antagonist, and rosaprostol, a synthetic prostaglandin. Further, the results obtained by these schedules of treatment were compared with those achieved by the previously described polyantihistaminic treatment (ie, the association of anti-H1 plus anti-H2 receptor blockers). The present investigation suggests that the cytoprotective drugs are more effective than the antisecretive ones (ie, the anti-H2). Recently, anti-H2 drugs and ketotifen were shown to be in vitro inhibitors of the immune response and cromolyn was demonstrated capable of exerting an enhancing effect on T cell proliferation. In the present study we tested the effect of pirenzepine on several immunologic parameters, such as lymphocyte proliferation (through different activation pathways) and lymphokine (interleukin-2 and interferon-gamma) production. Since we found that pirenzepine does not affect the immune response and in consideration of its clinical efficacy, we consider this cytoprotective drug a valuable tool in the treatment of adverse reactions to foods.