Introduction
Necrotising otitis externa (NOE), sometimes referred to as malignant otitis externa, is a rare but serious complication of acute otitis externa. It is a progressive infection of the external ear canal. If allowed to progress, there is a significant morbidity and mortality (1)(2)(3)(4).
Patients usually present with severe unremitting otalgia, otorrhoea, hearing loss, and in more advanced cases cranial nerve palsy, neurological infection and sepsis. Well-established risk factors for NOE are age, diabetes and other conditions that compromise immune function. (1) First coined ‘malignant’ otitis externa in 1968 (5), incidence of the disease appears to be increasing. Pseudomonas aeruginosa has historically been the most common causative organism. More recently non-pseudomonal bacteria such as methicillin-resistant staphylococcus aureus (MRSA) and even fungal infections such as Candida are frequently being recognised (6)(7).
The mainstay of treatment is long-term, high dose intravenous antibiotics (1)(8). Treatment duration may vary from 6 weeks to 3 months, dependent on individual patient risk factors (9). Although there is a role for local surgical debridement , the benefits are limited and it serves primarily to obtain deep samples for microbiology in resistant cases for those with severe complications or who are non-responsive to medical therapy (10)(11).
Despite this prolonged treatment, there is no robust data on the complications of antibiotic-related therapy of NOE. Anecdotally, patients are required to change antimicrobial therapy multiple times throughout treatment as a direct result of these complications.
The objective of this study was to: Calculate the number of different antibiotic regimes typically used in the treatment of NOE and classify the different clinical reasons mandating a change in antibiotic therapy