Circumscribed palmoplantar hypokeratosis

Circumscribed palmoplantar hypokeratosis (CPH) is a rare acquired dermatosis first described in 2002. It affects mostly the thenar or hypothenar eminences of palm middle-aged elderly women and manifests clinically with sharply limited, annular erythematous plaques depressed surface, rimmed by slightly raised, keratotic border. Microscopically, circumscribed shows sharp decrease horny layer thickness, few, if any, associated changes (parakeratosis, dermal inflammation). Despite characteristic clinical microscopic aspect, disease remains poorly known, as does its pathogenesis, even several hypotheses have been proposed (clonal epidermal malformation, disorder differentiation/keratinization and/or desquamation, human papillomavirus– trauma-induced disease). Several therapies varying results, best ones achieved surgical excision; however, because benign, intervention optional. © 2020 Elsevier Inc. All rights reserved.