Abstract
Amoxicillin-associated rash is a well-documented phenomenon in Epstein-Barr virus (EBV)-related infectious mononucleosis. This case highlights a notable course where amoxicillin was administered during the latent phase of EBV infection, and the characteristic rash appeared following the clinical onset of infectious mononucleosis. A seven-year-old girl received amoxicillin for acute otitis media during EBV's latent phase. After developing fever, conjunctival injection, lip redness, cervical lymphadenopathy, and a generalized rash, she was initially diagnosed with Kawasaki disease and treated with intravenous immunoglobulin and aspirin. Serological testing later confirmed acute EBV infection, and the rash was attributed to prior amoxicillin use. This case illustrates that aminopenicillins, such as amoxicillin, can trigger characteristic rashes after the onset of infectious mononucleosis, even when administered during the infection's latent phase. It highlights the importance of detailed medication history-taking, particularly regarding drug use during the latent period, and the consideration of viral etiologies in febrile illnesses with rash, especially when symptoms overlap with systemic inflammatory conditions.