Inverse papular acrokeratosis of oswaldo costa: a case report.

Acrokeratoelastoidosis of Oswaldo Costa, or inverse papular acrokeratosis, is a rare genodermatosis first described in 1952 by Oswaldo Costa, a Brazilian dermatologist. It is characterized by flesh-colored papules on the lateral aspects of the palms and soles and dorsum of hands. The histological features are hyperkeratosis, hyalinized and homogenous collagen, and a decrease in and fragmentation of the elastic fibers (elastorrhexis). In the absence of elastic fiber fragmentation, a similar clinical presentation is diagnosed as focal acral hyperkeratosis. Many cases of inverse papular acrokeratosis of Oswaldo Costa may have been considered focal acral hyperkeratosis since it can be difficult to find the elastorrhexis. The authors report a case of a 51-year-old woman with inverse papular acrokeratosis of Oswaldo Costa with poor response to topical treatments.