A 2-year-old unvaccinated boy presents with a rash about 2 weeks ago after visiting Disneyland with his family. Parents note that he started to have a high fever about 3 days ago with associated cough and runny nose. His eyes also appeared slightly red. Yesterday, he developed a maculopapular rash that started behind his ears before spreading to his face and trunk. This morning, parents also noted the rash appeared to be coalescing and had extended to his arms and legs.