Aquagenic urticaria: a report of two cases.

Aquagenic urticaria is a rare form of physical urticaria, in which contact with water evokes wheals. A 19-year-old man and a 4-year-old boy complained of recurrent episodes of urticaria. Urticaria appeared while taking a bath or a shower, in the rain, or in a swimming pool. Well-defined pin head to small pea-sized wheals surrounded by variable sized erythema were provoked by contact with water on the face, neck, and trunk, regardless of its temperature or source. Results from a physical examination and a baseline laboratory evaluation were within normal limits. Treatment of the 19-year-old man with 180 mg fexofenadine daily was successful to prevent the wheals and erythema. Treatment with 5 ml ketotifen syrup bid per day resulted in improvement of symptoms in the 4-year-old boy.