Angiokeratomas: an update.

Angiokeratomas are vascular lesions which are defined histologically as one or more dilated blood vessel(s) lying directly subepidermal and showing an epidermal proliferative reaction. At the center of pathogenesis there is a capillary ectasia in the papillary dermis. The epidermal changes in all forms of angiokeratoma are secondary. The different entities causing vessel ectasia lead to the many clinical variants of angiokeratoma. Current classification distinguishes between widespread forms (angiokeratoma corporis diffusum), which is usually associated with an inborn error of metabolism, and localized forms, which include solitary angiokeratoma, Fordyce's angiokeratoma, angiokeratoma circumscriptum naeviforme and angiokeratoma of Mibelli.