A 7-year-old previously healthy boy presents to the emergency room with a rash and mouth pain.
His mother took him to see his primary care physician (PCP) 1 week prior with a 2-week history of cough, subjective fever, and malaise; he was prescribed amoxicillin for presumed pneumonia. Five days into the antibiotic course, he developed an itchy rash and mouth sores.
His mother reports markedly diminished intake over the previous 24 hours, but no emesis or diarrhea. He has no known medication or food allergies. In the emergency room (ER), his temperature is 102°F (38.9°C), heart rate 122 beats/min, blood pressure 119/73 mm Hg, respiratory rate 18 breaths/min, and oxygen saturation 97% on room air.
On physical examination, he has bilateral conjunctival injection, ulcers on his tongue and lower lip (Figure 26–1), and purpuric macules and bullous lesions on his torso and extremities. Chest x-ray reveals an infiltrate in the right lower lobe.
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