Derm Dx: A rash after a streptococcal throat infection

The patient is a 16-year-old female who developed a rash 2 weeks ago. The dermatitis appeared suddenly and was preceded 10 days earlier by a streptococcal throat infection. She is otherwise in good health and takes no oral medications. She denies sexual activity. Examination reveals multiple erythematous papulosquamous patches on her trunk and extremities. Her face and scalp are unaffected.