Angiokeratomas are vascular malformations characterized by dilated superficial papillary dermis capillaries with overlying epidermal acanthosis and hyperkeratosis. Clinical variants include: solitary papular angiokeratoma (often on the lower extremity, sometimes after trauma), angiokeratoma of Fordyce (scrotum, vulva, often increasing with age and elevated venous pressure), angiokeratoma of Mibelli (acral, autosomal dominant, associated with chilblains), angiokeratoma circumscriptum naeviforme (congenital, segmental on a leg or trunk), and angiokeratoma corporis diffusum (widespread, classically associated with Fabry disease and other lysosomal storage disorders).
Lesions are 1-5 mm dome-shaped or verrucous papules ranging from bright red to dark purple-black, occasionally bleeding after trauma. Dermoscopy shows red lacunae with white-veil hyperkeratosis. Clinical recognition is usually sufficient, but diffuse angiokeratoma in a young patient warrants screening for Fabry disease (alpha-galactosidase A activity, genetic testing, urinary Gb3) and other lysosomal disorders. Histopathology shows dilated dermal capillaries with overlying epidermal acanthosis and hyperkeratosis.
Solitary symptomatic lesions can be removed with electrosurgery, CO2 laser, pulsed dye laser (for color), or surgical excision. Multiple Fordyce angiokeratomas usually require no treatment; cosmetic concerns or bleeding indicate laser ablation. Angiokeratoma corporis diffusum management focuses on the underlying lysosomal disease (enzyme replacement therapy for Fabry disease with agalsidase alfa or beta), as cutaneous lesions are markers rather than primary targets. Patient education and monitoring for trauma-induced bleeding are routine.