Abstract
Acanthosis nigricans (AN) is a common chronic disorder that is characterized by velvety-like, hyperpigmented, hyperkeratotic plaques, typically in intertriginous areas. However, atypical presentations have been reported. Here we present a five-year-old boy presented with a one-year history of asymptomatic slowly progressing skin lesions. He is a known case of type 1 diabetes mellites on insulin treatment, otherwise healthy. The review of systems was unremarkable. No similar case was found in the family. Skin examination revealed multiple tiny non-scaly brownish papules on the medial aspects of the upper thighs, bilaterally. Differential diagnosis included skin tags, viral warts, and dermatosis papulose nigra (DPN). Dermoscopic findings revealed a velvety-like appearance on the papules and the normal skin surrounding the papules. A 2-mm punch skin biopsy of the papule revealed papillomatosis of the epidermis, and the granular layer was normal. The dermis was normal. On the basis of the above clinicopathological findings, specifically the velvety texture of the normal skin surrounding the papules, the patient was diagnosed with ANs. The parent was reassured, and we started the patient on daily tretinoin cream.