An 11-year-old boy had a generalized rash of 5 days’ duration. There was no associated fever, malaise, lethargy, headache, arthralgia, or pruritus. The past history included varicella at the age of 2 years. His past health was otherwise unremarkable. Two weeks prior to assessment, his 5-year-old brother developed varicella. On examination, there were numerous discrete, erythematous maculopapules evenly distributed over the trunk and extremities (Figure). Some of the lesions had a crusted surface. The face, scalp, mucous membranes, palms, and soles were spared. There was no lymphadenopathy or hepatosplenomegaly. The physical examination results were otherwise normal.
What is your diagnosis?