What is the treatment for malignant otitis externa in ENT?

Treatment of Malignant Otitis Externa

The treatment for malignant otitis externa requires aggressive management with systemic antipseudomonal antibiotics (typically fluoroquinolones like ciprofloxacin) for 6-8 weeks, combined with careful aural toilet via microscopic suctioning, and close monitoring for complications such as cranial nerve involvement. 1, 2

Diagnosis and Risk Factors

• Malignant otitis externa (MOE) is an invasive infection of the external auditory canal that can spread to the temporal bone and intracranial structures, with Pseudomonas aeruginosa being the causative agent in more than 90% of cases 1, 2
• Major risk factors include diabetes mellitus, immunosuppression, and advanced age 1
• Red flags include severe otalgia (pain out of proportion to exam), purulent otorrhea, cranial nerve deficits (especially facial nerve involvement), and previously diagnosed otitis externa not responsive to therapy 1

Initial Management

• Early consultation with an otolaryngologist is essential when MOE is suspected 1
• Atraumatic cleaning with aural suctioning under microscopic guidance is recommended for patients with risk factors or established malignant otitis externa 3
• Avoid ear canal irrigation with water in diabetic or immunocompromised patients, as this has been implicated as a contributing factor to malignant otitis externa 3

Antibiotic Therapy

• Systemic antibiotics with pseudomonal coverage are required, with fluoroquinolones (particularly ciprofloxacin) being the treatment of choice 4, 2
• The duration of antibiotic therapy is typically prolonged (6-8 weeks) 2
• Antibiotic selection should be guided by culture and sensitivity results from ear canal drainage 4, 5

Surgical Management

• Local debridement of necrotic tissue is often necessary 5
• Aggressive surgical management may be required in advanced cases, though surgery is not the primary treatment modality for MOE 6
• Facial nerve decompression may be indicated in cases with facial nerve palsy 5

Monitoring and Follow-up

• Monitor therapy response through:
  • Normalization of erythrocyte sedimentation rate (ESR) 5
  • Control of underlying diabetes mellitus 5
  • Improvement on imaging studies (CT and radioisotope scanning) 5
• Gallium-67 citrate scan is particularly useful for diagnosis and monitoring disease regression in response to treatment 4, 5

Adjunctive Therapies

• Hyperbaric oxygen therapy may be beneficial, particularly in cases with facial nerve involvement 5, 6
• Control of diabetes is essential for effective treatment 5

Complications and Prognosis

• Complications include cranial nerve involvement (most commonly facial nerve), intracranial abscess, and meningitis 1
• The mortality rate can be as high as 53% when facial nerve paralysis is present 4
• With appropriate treatment, cure rates of approximately 95% can be achieved, though recurrence occurs in about 10% of cases 6

Common Pitfalls to Avoid

• Failure to recognize MOE in elderly diabetic patients with persistent ear pain and discharge 1
• Using ear canal irrigation in diabetic or immunocompromised patients 3
• Inadequate duration of antibiotic therapy 2
• Failure to monitor treatment response with appropriate imaging and laboratory studies 5