A 7 yr old, whose immunizations were up-to-date, was brought to Dr in Feb bc of feverheadachemalaisediagnosis?

A seven yerar old , whose immunizations were up-to-date, was brought to the physician's office in Februrary of fever, headache, malaise, sore throat and rash. Fever and sore throat began two days earlier. The rash began on the day of clinic visit. On examination, she appeared alert but apprehensive. Significant findings included a diffuse red rash that blanched on pressure. The tongue is red and the papillae are enlarged. The pharynx appeared red and thick exudates covered the posterior pharynx and the tonsillar area. The anterior cervical nodes are enlarged and tender. Throat culture was obtained. What is the diagnosis? What is the etiologic agent? How was this disease probably acquired?