Malignant Otitis Externa and Atypical Skull Base Osteomyelitis

Abstract

ABSTRACT Introduction: Malignant otitis externa/ Skull base osteomyelitis is a common yet challenging disease to establish diagnosis and manage efficiently to achieve a complete cure. We aimed to study the clinicopathological and radiological profile of Malignant Otitis Externa and atypical skull base osteomyelitis in the COVID-19 era. Materials and Methods: Ours is a descriptive observational study conducted in an ambispective manner. It includes 11 patients diagnosed with either malignant otitis externa or atypical skull base osteomyelitis from 2015 to 2023. The clinicopathological, radiological, and management details of these patients were collected from their respective case sheets. The patients were followed up to learn their current status. Results: Among the 11 patients, 4 were from the pre-COVID period and the remaining 7 were from the post-COVID period. 10 patients had malignant otitis externa or lateral SBO and 1 had atypical/Central skull base osteomyelitis. All the cases were associated with type II diabetes mellitus, with 64% relying on insulin. Otalgia (100%), otorrhea (82%), aural fullness (73%), vertigo (27%), and facial nerve palsy (18%) were the symptoms on presentation and the external auditory canal granulation was seen in 82% on clinical examination. 82% of patients had an elevated erythrocyte sedimentation rate. Microbiology of the ear swabs revealed the growth of Pseudomonas aeruginosa in 36% of cases. 64% of patients had involvement mastoid seen in radiological imaging of the temporal bone. All the patients were treated as in-patients with long-term antibiotics and surgical debridement when needed and the average duration of hospitalisation was 18 days. Conclusion: Malignant otitis externa or skull base osteomyelitis can be diagnosed and managed adequately only when there is a high index of clinical suspicion in elderly diabetic patients with deep-seated earache. Meticulous clinical examination, serial documentation of clinical examination, ear swabs for culture and sensitivity, and imaging studies will help in staging the disease. The appropriate management includes histopathological examination of the EAC granulation tissue, followed by culture-sensitive antibiotics administration. Treatment must be monitored with regular Erythrocyte Sedimentation Rate levels and serial imaging of the temporal bone. Our study noted an apparent increase in the Malignant otitis externa during the COVID-19 pandemic.

Keywords

• Necrotizing Otitis externa, malignant otitis externa, Skull-base osteomyelitis, Diabetes mellitus