What is the treatment for malignant otitis externa (also known as necrotizing external otitis) in a patient with diabetes mellitus?

From the Guidelines

Malignant otitis externa in patients with diabetes mellitus requires prompt treatment with surgical debridement and systemic antibiotics.

Key Components of Treatment

• Surgical debridement to remove infected tissue and promote healing
• Systemic antibiotics to cover pseudomonal and staphylococcal infection, including methicillin-resistant S aureus, such as fluoroquinolones or cephalosporins

Diagnosis and Management

• A clinical diagnosis of necrotizing otitis externa can be confirmed with a raised erythrocyte sedimentation rate plus an abnormal computed tomography or magnetic resonance imaging scan 1
• Biopsy may be necessary to detect neoplasia if the diagnosis of malignant otitis externa is uncertain or response to therapy is incomplete
• Patients with diabetes are more likely to require systemic antibiotics and should not have their ear canals irrigated to remove debris, as it may predispose to necrotizing otitis externa 1

Important Considerations

• Pseudomonas aeruginosa is isolated from exudate in the ear canal in more than 90% of cases of necrotizing otitis externa 1
• Facial nerve paralysis may be an early sign of necrotizing otitis externa, with the glossopharyngeal and spinal accessory nerves less frequently involved 1

From the Research

Treatment Overview

The treatment for malignant otitis externa (MOE) in patients with diabetes mellitus involves a combination of approaches, including:

• Control of diabetes mellitus 2, 3, 4
• Antibiotic treatment, with a focus on antipseudomonal antibiotics due to the common presence of Pseudomonas aeruginosa 2, 3, 4
• Debridement of necrotic tissue 2
• Possible surgical management, particularly in cases of facial nerve palsy or refractory disease 2, 5, 4
• Hyperbaric oxygen therapy may be considered in certain cases, such as facial nerve palsy 2, 6

Monitoring and Prognosis

Monitoring of the disease is crucial and can be done through:

• Inflammatory markers, such as erythrocyte sedimentation rate and C-reactive protein 3, 6
• Radiologic techniques, including computed tomography (CT) scans and scintigraphy 2, 3, 4
• Close follow-up, with patients being monitored for at least a year post-treatment 4
• The use of universal scoring systems to assess the extent of disease and predict outcomes 6

Surgical Intervention

Surgical intervention may be necessary in certain cases, such as:

• Poor facial nerve function at initial presentation 5
• Refractory disease or affection of the facial nerve 4
• However, the impact of surgical intervention on clinical outcomes is not well established, and studies have shown mixed results 5