Palmoplantar keratoderma of punctate type: acrokeratoelastoidosis Costa.

A special type of punctate palmoplantar keratoderma occurring in 10 patients from six Finnish families is described clinically, histologically and ultrastructurally. Eight of the patients were women. The patients had symptomless, slightly elevated, transparent, round or oval, hyperkeratotic papules, 2 to 5 mm in diameter, located at the edges of the palms and fingers, the entire palms and wrists, and at the edges of the soles. The clinical picture resembled acrokeratoelastoidosis Costa. Six of the patients also had knuckle pad-like lesions on the interphalangeal joints of the fingers and toes. Three of the patients had recalcitrant warts and no wart virus antibodies were found in their sera. The pedigrees of three families are presented and an autosomal dominant inheritance pattern is suggested. The histology of the lesions revealed undulating hyperkeratosis with slight depressions on the epidermis, which was otherwise normal. The dermis was of normal thickness and both the elastic and the collagen fibres seemed to be microscopically normal. Ultrastructurally, however, the elastic fibres in the deep dermis showed pathological alterations in some cases. In conclusion, we consider the condition to be acrokeratoelastoidosis Costa, a variant of hereditary palmoplantar keratodermas.