A Boy With a Macular, Golden-Brown Patch
A 4-year-old boy presented with a 1.5-year history of a rash on his right buttock. There was no associated tenderness, pruritus, or erythema, and his mother noted that the lesion had been growing slightly since its onset. A review of systems was negative for any constitutional or integumentary symptoms, and the boy’s family history was unremarkable.
On physical examination, there was a 3.5 × 2 cm macular, golden-brown patch with scattered petechiae (“cayenne pepper”-like) on the right buttock (Figure 1). The results of the remainder of the examination were unremarkable.
What is causing the boy’s rash?
(Answer and explanation on the next page.)