Derm Dx: Asymptomatic reddish-purple papules

The lesions were Angiokeratomas — small, typically 2- to 5-mm, reddish-blue papules found on the scrotum, inner thigh, penile shaft, labia majora and lower abdomen. The papules consist of dilated blood vessels in the superficial dermis, covered by an epidermal...

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The lesions were Angiokeratomas — small, typically 2- to 5-mm, reddish-blue papules found on the scrotum, inner thigh, penile shaft, labia majora and lower abdomen. The papules consist of dilated blood vessels in the superficial dermis, covered by an epidermal hyperplasia.    

Angiokeratomas do not usually grow or change shape or color, and they rarely regress spontaneously. They can occur at any age. In younger patients, the lesions are typically smaller and more erythematous, while in older patients, they are larger and darker and have more scale. Angiokeratomas are typically asymptomatic, but they can bleed if scratched or damaged.

Several types of angiokeratomas exist. Sporadic angiokeratomas are solitary lesions found on all the areas previously noted, typically in patients older than 40 years. Angiokeratomas of Fordyce may be solitary or multiple and are most commonly seen on the scrotum or labia majora. They are also more prevalent in patients older than 40 years and may affect men more than women.

Angiokeratoma circumscriptum is rare and usually presents as a cluster of lesions at birth but may also appear later in life. Angiokeratoma corporis diffusum (Fabry disease) is a rare X-linked disorder that affects multiple organ systems.

The pathophysiology of angiokeratomas is unknown. Reports link many cases with conditions involving increased venous pressure, such as varicoceles, hernias and certain tumors, as well as cases not associated with increased pressure. And while it has been proposed that angiokeratomas are more common in men, there are no direct comparisons with women.

Diagnosis & Treatment

The differential diagnosis for angiokeratomas includes Fabry disease, malignant melanoma, malignant nevi and genital warts. Diagnosis is typically based on clinical appearance, history, and lack of other skin manifestations or symptoms. Generally, no further studies are indicated. How-ver, any suspicion for melanoma warrants biopsy.

Fabry disease should be suspected if numerous angiokeratomas (usually >100), especially in the lower groin and upper thighs, are accompanied by fever and pain in the hands and feet. A decrease in serum galactosidase A is diagnostic. Lack of this enzyme leads to insufficient breakdown of lipids, which are then deposited in the kidneys, heart, eyes and nervous system.

Disease management requires a multispecialty approach involving dermatologists, nephrologists, car-diologists, neurologists and ophthalmologists.           

Angiokeratomas do not usually warrant treatment. It is important, however, to allay patient fears about malignancy (based on lesion appearance) or sexually transmitted disease (based on location). Lesions can be removed via excision, cryotherapy, laser therapy or electrocautery.

Our patient was reassured as to the benign nature of his angiokeratomas. He chose not to pursue any treatment.

John C. Browning, MD, is an assistant professor of pediatrics in the dermatology section at the University of Texas Health Sciences Center in San Antonio. Joanna L. Harp, MD, is a dermatologist at NewYork-Presbyterian/Weill Cornell in New York.