Angiokeratoma is a benign skin condition characterized by small, discolored bumps on the skin’s surface. These lesions arise from dilated capillaries near the skin. While generally harmless, their appearance can sometimes cause concern.
Understanding Angiokeratoma
Angiokeratomas are typically small, raised spots that vary in color from dark red to purple or black. They often have a rough, wart-like, or pebbled surface due to thickened overlying skin. These bumps form when capillaries near the skin’s surface enlarge or rupture, pushing into the skin to create a papule. They usually measure less than 5 millimeters in diameter.
The lesions are firm to the touch and generally do not lighten when pressed, a characteristic that helps distinguish them from some other vascular lesions. Although most angiokeratomas are asymptomatic, they can sometimes bleed if irritated or scratched, or cause itching and a burning sensation.
Different Forms of Angiokeratoma
Angiokeratomas manifest in several distinct forms, each with unique characteristics. Solitary angiokeratoma appears as a single lesion, commonly found on the legs or arms, and is often harmless. Angiokeratoma of Fordyce is the most common type, frequently presenting as multiple dark red, purple, or black spots in the genital area, typically ranging from 1 to 5 millimeters.
Angiokeratoma of Mibelli, a rarer form, tends to affect adolescent girls and typically appears on the webbing between fingers and toes, as well as on knees, elbows, and breasts. These lesions may thicken and harden over time. Angiokeratoma circumscriptum is a rare variant that can be present at birth, initially appearing as flat, discolored lesions that evolve into raised, red, scaly patches or plaques, often on the legs, arms, or trunk.
Angiokeratoma corporis diffusum is characterized by widespread lesions across the body, commonly on the genitals, abdomen, and the area between the hips and knees. This form is often associated with underlying systemic conditions.
Causes and Associated Health Conditions
For solitary angiokeratomas, the exact cause is not fully understood, but they may arise years after localized injury or trauma. The tissues supporting capillary walls can lose elasticity, contributing to their formation. Angiokeratoma of Fordyce is often linked to increased pressure in local veins, such as those associated with varicoceles or inguinal hernias, and pressure during pregnancy can also lead to vulvar angiokeratomas. Angiokeratoma of Mibelli has been associated with cold exposure or acrocyanosis, a condition causing persistent bluish discoloration of the extremities.
Angiokeratoma corporis diffusum often indicates lysosomal storage disorders, rare genetic conditions. Fabry disease, an inherited metabolic disorder caused by alpha-galactosidase A enzyme deficiency, is the most notable. This deficiency leads to fatty substance accumulation in cells, including blood vessels, triggering angiokeratoma formation. Other associated lysosomal storage diseases include fucosidosis and galactosialidosis.
Diagnosis and Management
Diagnosis typically involves a visual examination by a dermatologist, often using a dermoscope for closer viewing. A skin biopsy may be performed to confirm diagnosis and rule out conditions like melanoma or genital warts. For angiokeratoma corporis diffusum, blood or genetic testing may identify underlying conditions like Fabry disease.
Most angiokeratomas are benign and do not require treatment. However, treatment may be considered for cosmetic reasons, or if the lesions bleed frequently, cause discomfort, or itch. Common treatment options include cryotherapy, which uses freezing temperatures, and electrosurgery, which employs heat to remove lesions. Laser therapy, using high-intensity light beams, is another effective method, with types like pulsed dye laser (PDL) and Nd:YAG laser. Surgical excision, cutting out the lesion, is also an option, particularly for larger angiokeratomas. While some treatments can cause scarring, the choice depends on the specific type of angiokeratoma and individual preferences.