A congenital case of circumscribed acral hypokeratosis.

Circumscribed acral hypokeratosis is a disorder characterized by areas of erythematous depressed skin with distinct histopathological findings typically found on the palmar and plantar surfaces. Most patients are middle-aged women who report a multiyear history. We present an 10-year-old African American boy who had an asymptomatic, irregularly shaped erythematous lesion on his left medial foot that had been present since birth. A biopsy showed an abrupt, well-demarcated decrease in the thickness of the stratum corneum layer, with no parakeratosis, that was consistent with a diagnosis of circumscribed hypokeratosis. This represents the first pediatric and congenital case of circumscribed hypokeratosis reported. We review the literature and discuss the ramifications of a congenital case on understanding the etiology of circumscribed hypokeratosis.