['Histamine is considered a major mediator in the process of gastric acid secretion. When acid peptic activity overpowers the mucosal defense mechanism, peptic ulceration may develop. Is the hyperreactivity of patients with duodenal ulcer to histamine also expressed in the skin?', 'The aim of the present study was to assess the reactivity of patients with duodenal ulcer to histamine as reflected in the skin, by comparing the erythema and the cutaneous blood flow response to histamine in duodenal ulcer patients and healthy controls.', 'Twenty volunteers participated in the study: 10 duodenal ulcer patients and 10 age and gender matched healthy controls. Histamine was topically administered to the back and to the volar side of the forearm, and the induced response was quantified by spectrophotometry and laser Doppler flowmetry (LDF). The extent of the response and time parameters were compared.', 'The maximum response, as measured by LDF, was greater in the peptic ulcer patients (P < 0.05) compared to healthy controls. Aging was accompanied by decreased responsiveness in both groups.'] Do duodenal ulcer patients exhibit a greater skin response to histamine?