Derm Dx: Symmetrical pink papules on the cheeks, arms and legs

A 3-year-old male presents with an eruption of pink papules on the cheeks, arms and legs that has been present for four days. The boy’s mother reports he has not been scratching the lesions.

Both the patient and his older sister had a recent cold, but the older sister does not have a rash. The mother thought the eruption was ...