Angiokeratomas are asymptomatic, benign vascular neoplasms that present as solitary or multiple, red-to-violaceous papules or plaques, sometimes with verrucous features. Five clinical subtypes of angiokeratomas are recognized (refer to individual subtypes for more detailed information and images):

• Angiokeratoma of Fordyce – The most common subtype of angiokeratoma. Angiokeratoma of Fordyce of the scrotum classically presents on the scrotum of men older than 50 years; angiokeratoma of Fordyce of the vulva is less common. Angiokeratoma of Fordyce is also seen on nearby sites such as the thighs. The pathophysiology is speculated to be increased venous pressure. These angiokeratomas are associated with vascular conditions such as varicoceles as well as older age and lichen sclerosus in females.
• Solitary angiokeratoma – These most commonly develop in the lower extremities of adults. The etiology is not well understood but is often considered to be a result of trauma or chronic irritation.
• Angiokeratoma of Mibelli – Primarily found in children and young adults, these lesions generally present on acral surfaces (ie, dorsal hands including the fingers and toes) that are more prone to vascular insufficiency. They present less commonly on the knees and elbows. Over time, lesions may become darker, hyperkeratotic, and verrucous. They may also form grape-like clusters as they evolve. The etiology is thought to be related to a genetic predisposition (with reported familial cases), trauma, and/or exposure to cold temperatures. There is a notable association with perniosis and acrocyanosis.
• Angiokeratoma circumscriptum – Lesions most commonly present at birth or in early childhood. They are found in clusters or in a linear distribution, most often affecting one lower extremity. They generally enlarge with age. There is an association with Klippel-Trenaunay-Weber syndrome, Cobb syndrome, port-wine stains, cavernous hemangiomas, and arteriovenous fistulas.
• Angiokeratoma corporis diffusum – Numerous punctate macules and papules in a "bathing trunk" distribution such as the buttocks and thighs; however, they may be distributed more diffusely. These angiokeratomas are seen in Fabry disease, a rare X-linked recessive lysosomal storage disorder. They are also associated with inherited metabolic disorders such as fucosidosis, sialidosis, Kanzaki disease, beta mannosidosis, aspartylglycosaminuria, galactosialidosis, and GM1 gangliosidosis.