Review Question - QID 109445

A 13-year-old boy presents to his primary care physician for a rash. He discovered the rash when he woke up this morning. The patient has a medical history of asthma and seasonal allergies. He recently visited his physician for pain associated with running and was prescribed ibuprofen. The patient switched from home school to a public school, where he joined the school's track team. He consumes a vegan diet per his parents' wishes. He also takes a multivitamin, vitamin D, calcium, fish oil, coenzyme Q10, and an antioxidant supplement. The patient has not seen a doctor since he was 5 years old other than this recent visit. His temperature is 99.5°F (37.5°C), blood pressure is 122/82 mmHg, pulse is 71/min, respirations are 12/min, and oxygen saturation is 99% on room air. On physical exam, the rash is blanching and is seen in Figure A. Pulmonary exam reveals bilateral air movement with minor wheezes. Which of the following is the most likely cause of this patient's presentation?