A previously healthy 4.5-month-old boy presented for evaluation of a rash over his distal extremities and trunk. The rash had been present for about 1 month and seemed to be increasing in number, size, and location. Medical history and family history were unremarkable. His examination was significant for a tender, erythematous, atrophic-appearing, nodulopapular rash over the trunk and lower and upper extremities. Nodular areas were superficial, firm, and mobile (Figure 1). He was growing at the third percentile for length and 1 SD lower than the third percentile for weight. He was also noted to have round facies and normal-length metacarpals and metatarsals. Radiography of a lower extremity lesion was performed
(Figure 2) as well as a skin biopsy (Figure 3) and laboratory evaluation.