Jonathan Theros ¹ Madison Wolfe ^2* Larry Kociolek ² Irini N Kolaitis ^2*

• ¹ Northwestern Medicine, Chicago, United States
• ² Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois, United States

Brainstem abscesses are remarkably rare with only a few reports in the pediatric literature. Their presence portends high morbidity and mortality and most commonly present in the setting of immunodeficiency. A 5-year-old boy with a history of recurrent acute otitis media presented to the emergency department with rash, otorrhea, confusion, and fever. He was found to be in septic shock secondary to P. aeruginosa bacteremia; skin exam revealed multifocal ecthyma gangrenosum. He was initially treated with intravenous ceftazidime. Despite adequate antibiotic coverage he had persistent fevers. Whole-body MRI revealed an expansile pontine mass; dedicated neuroimaging confirmed a 10 mm pontine abscess. Given the lack of neurological deficits on exam, he was treated non-operatively with intravenous cefepime for 9 weeks followed by oral levofloxacin for 30 days and made a nearly complete clinical recovery. Extensive immunodeficiency workup did not identify an immunologic defect. Prompt action through interdisciplinary care meetings and avoidance of early diagnostic closure resulted in an excellent neurological outcome for this patient with this rare case of a P. aeruginosa brainstem abscess.