Solar urticaria: a case with good therapeutic response to cimetidine.

A 25-year-old woman developed urticarial lesions after visible light irradiation. Orally administered cimetidine significantly inhibited the induction of urticaria, but H1 antihistamines did not suppress the weal formation. Our case suggests that a trial with H2 antihistamine should be considered for the treatment of solar urticaria.