An 18-year-old woman presented to clinic with acute pharyngitis with 4/4 Centor criteria. Rapid streptococcal antigen test was negative. The patient, who was allergic to penicillin, was prescribed azithromycin. Ultimately, after 5 days and without any corticosteroids, she presented to the emergency department with 10/10 chest pain and was admitted to the intensive care unit. CT showed nodular lung disease and blood cultures on admission grew Fusobacterium, likely Fusobacterium nucleatum. She sustained two cardiac arrests, three tube thoracostomies, acute kidney injury requiring dialysis and ventilatory failure requiring tracheostomy. After 16 days in hospital and 18 days in long-term acute care, the patient was discharged home. It is unclear how much of this could have been prevented by prescribing an antimicrobial that had activity against Fusobacterium When severe pharyngitis occurs, Fusobacterium needs to be considered as an underlying cause. In vitro macrolides have marginal activity against most anaerobes, such as this pathogen, and should be avoided.