Keratoderma hereditaria mutilans (KHM), or Vohwinkel's syndrome, is a rare genodermatosis consisting of hyperkeratosis of the palms and soles with a characteristic "honeycomb" appearance, keratotic structures taking the shape of a starfish and/or knuckle pads on the dorsal surfaces of the hands, and constricting bands (pseudoainhum) encircling digits of the hands and feet. We describe three cases of a variant of KHM with an associated ichthyosiform dermatosis in a pedigree consisting of 19 affected individuals through six generations. An autosomal dominant inheritance pattern for KHM was confirmed. One of the patients was successfully treated with isotretinoin, 0.6 mg/kg/day orally. We offer five hypothetical genetic models to account for the simultaneous expression of palmar-plantar keratoderma and ichthyosiform dermatosis.