A 15-month-old infant is brought to the clinic by his mother due to the presence of multiple skin nodules and poor feeding. The nodules first appeared several weeks ago and have been increasing both in size and in number. Physical examination reveals a tired-appearing boy resting in his mother's lap. The patient's temperature is 37.4°C (99.3°F), blood pressure is 90/60 mm Hg, pulse is 88/min, and respiratory rate is 20/min. His conjunctivae are pale and oral ulcers are noted. Diffuse erythematous nodules are observed on the trunk and perineal region, with several raised, tender spots on his head. X-ray of the skull reveals circular lytic lesions. A skin biopsy sample is taken