Clinical Profile, Risk Factors, and Treatment Response of Malignant Otitis Externa in Diabetic Patients

Abstract

Background: Malignant otitis externa (MOE) is a potentially life-threatening invasive infection of the external auditory canal that predominantly affects patients with diabetes mellitus.

Objective: To evaluate the clinical profile, risk factors, and treatment response of malignant otitis externa in diabetic patients.

Methods: This prospective observational cohort study was conducted at ENT department Bahawal Victoria Hospital/Quaid Azam Medical College Bahawalpur from September 2024 to June 2025, and included 170 diabetic patients diagnosed with malignant otitis externa. 

Results: The mean age of patients was 64.8 ± 10.9 years, and 104 (61.2%) were male. The mean duration of diabetes was 11.6 ± 6.3 years, with a mean HbA1c of 8.9 ± 1.5%. Severe otalgia (95.9%) and otorrhea (83.5%) were the most common presenting symptoms, while Pseudomonas aeruginosa was isolated in 119 (70.0%) patients. Patients with poor treatment response were significantly older (72.1 ± 11.4 vs. 63.2 ± 10.1 years; p<0.001) and had higher HbA1c levels (10.4 ± 1.6% vs. 8.5 ± 1.2%; p<0.001). Chronic kidney disease, facial nerve palsy, skull base osteomyelitis, prolonged hospitalization (16.4 ± 5.6 vs. 9.2 ± 3.8 days; p<0.001), and recurrence (36.7% vs. 6.4%; p<0.001) were significantly more common among patients with poor outcomes.

Conclusion: Malignant otitis externa in diabetic patients is associated with substantial morbidity, particularly among those with poor glycemic control and advanced disease. Early diagnosis, aggressive culture-directed antimicrobial therapy, optimal diabetic management, and close follow-up are essential to improve treatment outcomes and reduce recurrence.