Familial cutaneous mastocytosis.

Cutaneous mastocytosis appears to occur sporadically; however, familial inheritance has been reported in 50 families since the mid-1880s. We report four cases of telangiectasia macularis eruptiva perstans (TMEP) occurring in three generations of a family. Whereas most patients with TMEP manifest in adulthood, all of the members of this family developed initial lesions during childhood. This is the third documented instance of familial mastocytosis affecting members of three generations, and the first report of familial TMEP. Although the inheritance pattern is unknown, the presentation of disease in this family further supports the hypothesis of an autosomal dominant mode of transmission with incomplete penetrance.