Angiokeratoma corporis circumscriptum naeviforme with transepidermal elimination.

A 5-year-old Japanese boy visited our clinic for treatment of a dark bluish papulonodular lesion on his right thigh. The histopathology of the lesion indicated angiokeratoma corporis circumscriptum naeviforme. Topical antibiotics were prescribed for occasional bleeding from the site. Frequent bleeding started in April of 1992, when erythema and itching were observed around the angiokeratoma. Histopathology of the lesion showed heavy lymphoid cell infiltration around dilated capillaries and irregular acanthosis engulfing dilated capillaries. Interestingly, there were confined masses of red blood cells in the epidermal layer as well as both in and on the horny layer. This is a feature of transepidermal elimination. This transepidermal elimination appeared to be triggered or enhanced by the concomitant contact dermatitis due to topical antibiotics. To the best of our knowledge, this is the first report of angiokeratoma in which the angiokeratoma itself reduced in size through transepidermal elimination, possibly caused by contact dermatitis.