196 © 2003 European Academy of Dermatology and Venereology CASE REPORT JEADV (2003) 17, 196–199 Blackwell Science, Ltd Acantholytic dyskeratotic naevi following Blaschko’s lines: a mosaic form of Darier’s disease M Gilaberte, L Puig,* D Vidal, A Alomar Department of Dermatology, Hospital de la Santa Creu i Sant Pau, Av Sant Antoni M Claret, 167, 08025 Barcelona, Spain. *Corresponding author, tel. +34 93 2919013; fax +34 93 2919136; E-mail: lpuig@hsp.santpau.es ABSTRACT Darier’s disease (DD) is an autosomal-dominant skin disorder characterized by loss of adhesion between epidermal cells and abnormal keratinization. Several patients with unilateral, linear, ‘zosteriform’ or localized lesions have been reported. We report three cases of DD in a localized pattern corresponding to mosaicism type 1 according to Happle’s classification and review the literature about the genetic cause of DD and DD in a ‘zosteriform’ pattern. Key words: ATP2A2, Blaschko’s lines, Darier’s disease, mosaicism, SERCA, zosteriform Received: 17 December 2001, accepted 10 April 2002 Introduction Darier’s disease (DD) in a localized ‘zosteriform’ pattern was first reported by Kreibich in 1906. 1 Since then, several patients with unilateral, linear or ‘zosteriform’ epidermal lesions with the histological and clinical characteristics of DD have been reported. 2–5 Therefore, some investigators have suggested that these unilateral lesions should be classified as acantholytic dyskeratotic epidermal naevi rather than localized DD. However, there are reports suggesting that acantholytic dyskeratotic epidermal naevi are localized forms of dyskeratosis follicularis (DD). 6 We present three new cases of unilateral DD from the Department of Dermatology, Hospital de la Santa Creu i Sant Pau (Barcelona, Spain) and a review of the literature about the aetiology of DD. Case reports Patient 1 An 87-year-old man had an extensive pruritic eruption on the left side of his trunk for 40 years, which tended to worsen during summer and improve spontaneously in winter. None of his family members had a similar lesion. Examination revealed confluent hyperkeratotic and hyperpigmented papules, which were distributed according to Blaschko’s lines (fig. 1). There was no mucous membrane or nail involvement. A biopsy specimen revealed acantholytic dyskeratotic cells in the upper epidermis with suprabasal clefts. Mild hyperkeratosis, exocytosis, focal granulosis and lymphocytic cell infiltration were also observed (fig. 2). Topical treatment with 0.05% retinoic acid was minimally effective and led to significant irritation. Marked improvement was achieved following a 2-month course of treatment with oral acitretin, 10 mg/d. Systemic retinoids were stopped because of adverse effects (increased cholesterol serum level). Patient 2 A 20-year-old healthy woman had recurrent brownish papules on the left side of the trunk for 2 years. The lesions were pruritic and the dermatosis recurred after sun exposure. No other member of her family had skin problems. Physical examina- tion revealed small keratotic papules in a linear metameric distribution on the lateral part of the left trunk (fig. 3). Histological features were consistent with DD, showing corps ronds and grains, acantholysis, lacunae and lymphocytic infiltrate (figs 4 and 5). We made a diagnosis of segmental DD. Lesions improved after a 4-month course of treatment with topical 0.05% retinoic acid, but new lesions have been recurring during the summer.