Progressive cribriform and zosteriform hyperpigmentation
A healthy 28-year-old male presented with progressively increasing brown to black macules and patches arranged along the lines of Blaschko on the right side of abdomen and back. The onset of lesions was first from back and the spread towards abdomen. The lesion appeared at the age of 20 and has been progressive since then. He had no history of any preceding eruption, drug intake or trauma to the area. There was no evidence of internal diseases and no family history of skin abnormalities.\nCutaneous examination revealed linear, cribriform, brown to black pigmentation along lines of Blaschko extending from back to abdomen till pubic area on right side []. Multiple macules coalescing at places to form patches were seen and at some places lesions were slightly palpable with velvety appearance. Laboratory studies, including complete blood cell count, liver and renal function tests and serum electrolyte, were within normal limits.\nA diagnosis of zosteriform lichen planus, non-hypertrichotic variant of Becker's nevus and nevoid acanthosis nigricans was thought. A skin biopsy specimen was obtained from most recent lesion which revealed uniformly increased pigmentation within the basal keratinocytes [Figures and ]. There were few dermal melanophages with mild pigment incontinence without much inflammatory infiltrate in the dermis []. Nevus cells were absent. Absences of lichenoid infiltrate and interface change ruled out lichen planus. Lack of an increase in smooth muscle fiber and hair follicles ruled out Becker's nevus. Lack of church-spire hyperkeratosis, presence of heavy basal layer pigmentation with mild pigment incontinence ruled out epidermal nevus and acanthosis nigricans. Also clinically there were many skip areas giving a cribriform appearance. Thus, the diagnosis of PCZH was made on clinicopathological correlation.