Hypokératose acrale circonscrite (HAC) : utilité diagnostique de la dermoscopie

[Cases of circumscribed palmar or plantar hypokeratosis]

Circumscribed palmar or plantar hypokeratosis (CPH) is a depressed, well-delimited, erythematous lesion usually found in the thenar and hypothenar regions of the palms or the soles, predominately in women. It was first described by Pérez et al. in 2002 as a benign entity of unknown origin. Histologically, the depressed area corresponds to a thinning of the stratum corneum. It is a well-demarcated lesion with a sharp stair in the stratum corneum between normal and involved skin and the affected corneocytes are more eosinophilic than normal. We present two new cases of CPH, both occurring in females and in the hand, one of which was located in the thenar region and the other in the finger. We discuss the histopathological and dermatoscopical findings.

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