An 8-year-old girl presents to the emergency department with a one-day history of rash. The rash is erythematous, macular, blanching, and covers her trunk and extremities. It is not painful or pruritic, and there are no vesicles, bullae or mucosal lesions noted. She has bilateral lymphadenopathy in the posterior cervical chains with splenomegaly on palpation of her abdomen. The rest of her physical exam is normal. Her pediatrician started an antibiotic last week for pharyngitis but she has not improved. What is the most likely etiology of her rash?
-DRESS Syndrome
-Mononucleosis
-Stevens-Johnson Syndrome
-Type I Hypersensitivity reaction