Angiokeratoma corporis diffusum (ACD) is typically characterized by innumerable small red to black papules which occur in clusters and are situated symmetrically in the bathing trunks area. The number of lesions and the extension of the body increase steadily with time so that generalization and mucosal involvement are common. The single lesion begins with a minute reddish papule which enlarges to up to 10 mm in diameter, becomes dark red to black with a discrete keratotic overgrowth. Histologically, the papules are characterized by superficial dilated capillaries in papillary dermis with epidermal proliferation. The phenotype is Human Phenotype Ontology id HP_0001071 (Angiokeratoma corporis diffusum). Also known as: Fabry syndrome.