[Retarded bullous dermographism].

A case of what we denominate Bullous Delayed Dermographism in a woman who had neither allergic nor urticarial antecedents is registered. We comment the features of the lesions which appeared after a period of 4 to 12 hs. This lesions appeared by friction or percussion. We describe the existence of an endocrine and psychological predisposition mechanism and the non specificity of the histopathological characters. The nonexistence of bibliographical antecedents of the illness is noted. Also its difference with bullous and pressure urticaria. This differentiation is based on clinical features, and the nonexistence of allergic antecedents and urticarial lesions. Also on the existence of friction mechanism different to the simple pressure and the nonexistence of immunoglobulins in the subepidermal blister.