Symmetrical interdigital keratoderma of the hands

We report the case of a 26-year-old man affected by a symmetrical keratoderma localized to the interdigital spaces of the fingers. No occupational, traumatic, or irritant factors were discovered. Clinical and histological features were consistent with the diagnosis of symmetrical interdigital hyperkeratosis, a sporadic disorder described by Frei in 1926. We believe this condition to be less rate than the few cases reported in the literature would suggest.