A 19-year-old, previously healthy man presented with 3 days of cough, high-grade fevers (40 °C), and dyspnea. Apart from a resolved history of seizures not requiring medications, he had no medical or surgical history. He had no known drug allergies. He took montelukast for allergies and trimethoprim-sulfamethoxazole (TMP-SMX) for 2 weeks before admission for acne, but no other medications, including over-the-counter medications and supplements. He had animal exposures to a new puppy and a friend's bird. He had no history of smoking, vaping, or recreational drug use. His paternal grandmother had rheumatoid arthritis.