Progressive cribriform and zosteriform hyperpigmentation: a clinicopathologic study

Background  Progressive cribriform and zosteriform hyperpigmentation (PCZH) is a disorder of pigmentation. Although several cases of PCZH have been reported, no clinicopathologic studies of the condition have been published in the English‐language literature. Objectives  The purpose of this study was to determine the clinical characteristics and histologic findings of PCZH. Methods  Between 1999 and 2009, 30 patients were diagnosed with PCZH in our Department of Dermatology. Medical records, clinical photographs, and pathologic findings for each patient were retrospectively reviewed. Results  The patients included 16 men and 14 women. The mean age at onset was 14.27 years. The trunk was the most common site of involvement. Microscopic examination showed an increased level of melanin pigment in the basal cell layer compared with adjacent normal skin, although no significant difference existed in the number of melanocytes. Pigmentary incontinence was observed in 13 of 30 cases. Conclusions  There was no significant difference in prevalence, age at onset, and duration of lesions between male and female patients with PCZH. The lesions corresponded to the lines of Blaschko and were localized rather than exhibiting diffuse patterns. A common feature of the histopathologic findings was higher melanin content in the lesions than in normal skin but with no significant difference in the number of melanocytes.