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