Marginal papular acrokeratodermas: a unified nosography for focal acral hyperkeratosis, acrokeratoelastoidosis and related disorders.

Several entities, quite often similar, share keratotic papules, usually crateriform, along the border of the hands and feet as a common clinical finding. These conditions are acrokeratoelastoidosis of Costa, focal acral hyperkeratosis, acrokeratoelastoidosis of Matthews and Harman, mosaic acral keratosis, hereditary papulotranslucent acrokeratoderma, acrokeratoderma hereditarium punctatum, degenerative collagenous plaques of the hands, keratoelastoidosis marginalis and digital papular calcinosis. We describe two further cases of focal acral hyperkeratosis in two Caucasian women, review the clinical and histological features of the related conditions and suggest that some are variants of the same entity. We propose the simplified concept of marginal papular acrokeratodermas that may be divided into (1) the hereditary type (subdivided into that with and without elastorrhexis) and (2) the acquired type.