Release of gastric histamine in patients with urticaria and food allergy.

In a clinical study the participation of histamine in the allergenic response of patients with food allergy was investigated. The resting levels of gastric tissue and plasma histamines of 10 patients were slightly higher than the respective values of normal volunteers. 5 minutes after local intragastral allergenic provocation a decline of the mucosal histamine content of the allergen-treated area was noticed. Parallel investigations on the mast cell content of the stomach mucosa revealed a parallel decrease of the o-phthaldialdehyde stained cells, whereas the number of toluidine blue stained cells remained unchanged. These data are in accordance with an antigen-induced IgE-dependent liberation of the mast cell histamine stores.