A Teen Too Exhausted to Attend School

The 15-year-old presents with a sore throat, congestion, and malaise. Her mother, afraid she will infect her siblings, requests a strep test. Review the history, watch the video exam. What’s your diagnosis?

This 15-year-old girl was seen for a sore throat of 4 days’ duration, accompanied by fever, fatigue, headache, congestion, and yellow nasal discharge. She reports no cigarette smokers in the home. Physical examination reveals palatal petechiae and mild submandibular lymphadenopathy. She is an otherwise healthy teenager: height, 64"; weight, 114.6 lb. Vital signs: temp, 36.5°C (97.7°F); HR, 94 beats/min; RR, 14 breaths/min; BP, 120/80 mm Hg; SpO2, 99% on room air. Current medications are ibuprofen and acetaminophen, taken for current symptoms. The child’s mother requests a throat culture be taken for a rapid “strep test.”

What is the most likely cause of this teenager’s symptoms?