[Familial aquagenic urticaria: report of two cases and literature review].

Aquagenic urticaria is a rare form of physical urticaria, characterized by pruritic wheals that appear following contact with water, independently of its temperature. There are few reports of cases of aquagenic urticaria, and only five include the familial form. We present the first case of familial aquagenic urticaria in Brazil (mother and daughter). Both patients presented wheals following contact with water, especially when showering, regardless of its temperature. The mother reported onset of urticaria four years before and the daughter presented wheals since birth. For diagnostic purposes, they were submitted to a challenge test with water, and both subjects presented wheals, as well as to tests using ice cubes in plastic bag with dermographometer and challenge tests for cholinergic urticaria, with no appearance of lesions, excluding other forms of physical urticaria.