A 10-year-old boy presented with flat, brown, oval lesions that had developed on his trunk in the past year. The first one appeared on his chest as a solitary brown patch, and, shortly afterward, more appeared on his trunk as well as his arms and legs. The patient denied any preceding redness, and the lesions were asymptomatic. The eruption was not preceded by the application of new topical products or by the use of any oral medication.
Physical examination demonstrated a well-developed, well-nourished Asian boy with Fitzpatrick type III skin. There were multiple round, brown macules and patches admixed with some thin plaques with a thickened surface on the neck, trunk, and proximal aspect of the extremities (Figure 1 and Figure 2). Stroking of a representative lesion did not result in urticaria. The conjunctivae, oral mucosa, palms, soles, and nails were uninvolved. A skin scraping with a potassium hydroxide preparation was negative for fungal elements. A diagnostic skin biopsy was performed (Figure 3).