BACKGROUND: Pseudomonal infection is the most common cause of malignant otitis externa (MOE), which typically affects elderly diabetic patients. Fungi are a rare cause of MOE. MOE can be life-threatening if not recognized and treated promptly. It can result in a wide spectrum of complications, including skull-base osteomyelitis, cranial nerve palsy, cerebral venous thrombosis, and brain abscess. Pseudoaneurysm formation of the intracranial vessels is a life-threatening complication of MOE that is seldom reported in the literature.

CASE REPORT: We report the case of a 66-year-old diabetic man with MOE who was initially treated with antipseudomonal antibiotics after negative initial culture results. His MOE resulted in a cascade of complications, including facial nerve palsy, skull base osteomyelitis, and sigmoid sinus thrombosis, and culminated in left maxillary artery pseudoaneurysm formation resulting in massive epistaxis and hemodynamic instability. Endovascular embolization resulted in a successful obliteration of the pseudoaneurysm. A subsequent functional endoscopic sinus surgical (FESS) tissue biopsy confirmed Candida glabrata as the etiological agent. The patient was successfully treated with antibiotics and antifungal and anticoagulation therapy, and was discharged home in good condition.

CONCLUSIONS: A high index of suspicion for the diagnosis of fungal MOE, particularly in intractable cases of MOE with negative initial cultures, should be maintained. Pseudoaneurysm formation is a life-threatening complication of MOE that is seldom reported in the literature and should be suspected in any patient with MOE who presents with epistaxis or intracranial bleeding.

Keywords: Aneurysm, False, Candida glabrata, otitis externa, Anti-Bacterial Agents, Antifungal Agents, Diabetes Mellitus, Type 2, Embolization, Therapeutic, Epistaxis, Maxillary Artery, Pseudomonas Infections, Risk Assessment