Otogenic Enterobacter cloacae meningitis complicated with pneumocephalus

Pneumocephalus refers to a pathologic collection of gas within the cranial cavity and is mostly caused by head trauma and neurosurgical procedures. Spontaneous nontraumatic pneumocephalus is a very rare condition. We herein report an unusual case of community-acquired bacterial meningitis with a combination of acute otitis media, Enterobacter cloacae, and nontraumatic pneumocephalus. A 75-year-old woman presented with fever, mental change, and neck stiffness. Brain imaging demonstrated pneumocephalus and fluid collection in the left mastoid air cells. E. cloacae was isolated from both blood and otorrhea cultures, and the patient was successfully treated with intravenous ceftazidime for 3 weeks. Although E. cloacae is a very rare cause of community-acquired bacterial meningitis in adults, it should be considered as a possible pathogen in otogenic meningitis complicated with pneumocephalus.