Angioma serpiginosum (AS) is a benign congenital skin disease characterized by progressive dilation of the subepidermal skin vessels manifesting as purple punctate lesions usually appearing on the lower limbs and buttocks and following the lines of Blaschko. The disease is Monarch Disease Ontology identifier MONDO_0019803 (angioma serpiginosum). Also known as: angioma serpiginosum of skin.