In 1896, John Addison Fordyce first described angiokeratomas of Fordyce on the scrotum of a 60-year-old man.
Angiokeratomas are typically asymptomatic, 2- to 5-mm, blue-to-red papules with a scaly surface located on the scrotum, shaft of penis, labia majora, inner thigh, or lower abdomen. Histologically, they are composed of ectatic thin-walled vessels in the superficial dermis with overlying epidermal hyperplasia.
“Angiokeratoma” is a broad term that encompassing various asymptomatic hyperkeratotic vascular disorders accompanied by a histologic combination of hyperkeratosis and superficial dermal vascular ectasia.
More specifically, angiokeratomas can be categorized into localized and systemic forms.
There are four major localized forms with different presentations. First, solitary papular angiokeratomas typically occurs on the legs. Second, Fordyce-type angiokeratomas are usually localized to the scrotum and vulva. Third, angiokeratoma circumscriptum naviforme is the congenital form that presents as multiple, hyperkeratotic, papular, and plaquelike lesions, usually unilaterally on the lower leg, foot, thigh, buttock, and occasionally elsewhere. Finally, bilateral angiokeratomas, also known as the Mibelli type, occur on the dorsa of the fingers and toes.
The generalized systemic form, angiokeratoma corporis diffusum, is usually associated with metabolic disorders, the most common being Fabry disease or fucosidosis. Although Fabry disease is associated with the generalized presentation, a case report in 2010 recommends considering Fabry disease in all male patients with angiokeratomas, even if localized to the scrotum.
Although the pathogenesis and clinical presentation vary, the histologic features are similar for all forms.
Precise epidemiological data are lacking, although estimations have been made. The principal morbidity comes from bleeding, anxiety, and overtreatment due to misdiagnosis by physicians. Usually, these lesions do not require treatment. If treatment is needed, locally destructive methods including electrocoagulation, excision, cryotherapy, or laser therapy may be used.