Successful treatment of cold angio-oedema by H2-antihistamine therapy.

Two patients with severe cold angio-oedema were practically relieved from their symptoms during H2-blocker therapy (cimetidine 1 000 mg daily). Classic H1-blocker therapy had no effect on their symptoms and combined H1- and H2-blocker treatment was just as effective in ameliorating the symptoms of cold angio-oedema as H2-blocker treatment alone. A low dose of the H2-blocker (400 mg cimetidine daily) was almost able to control the angio-oedema formation after cold exposure, but provoked typically urticarial lesions. This observation strongly indicates that H2-receptors may play an important role in the pathogenesis of cold angio-oedema and that a massive, subcutaneous, cold angio-oedema may obscure cold urticarial lesions.