Circadian variations of histamine binding to lymphocytes and neutrophils and skin reactivity to histamine in atopic and healthy subjects.

Introduction: Numerous pathophysiological conditions change during 24-hour periods. Histamine, the main mediator in allergic reactions, exerts a multiplicity of pathophysiological actions through binding to specific receptors on effector cells. Nocturnal exacerbation of symptoms occurs in many atopic diseases in which histamine is an important mediator.