Pediatric Puzzler: Cough, chest pain in an adolescent athlete: Factors (five) at play

After the initial diagnosis of right-middle-lobe pneumonia, a 16-year-old girl completed a first course of azithromycin and then felt better for a time. But now she complains again of a productive cough, chest pain that radiates to her right shoulder while coughing, and dyspnea on exertion.