A worrying development in the microbiology of otitis externa

Methicillin-resistant Staphylococcus aureus (MRSA) is causing growing concern in hospitals. There has been a steady increase in the number of cases of nosocomial MRSA infections recently and this will no doubt apply to otitis externa, one of the most common ENT infections. The total number of cases of otitis externa presenting to the Accident and Emergency Department over a 3-month period was recorded and the offending microbes cultured and tested for drug sensitivities. Although Pseudomonas aeruginosa was the most frequent organism, 30% of patients grew S. aureus. Of these, 6% (15 patients) were MRSA cultures. The contact histories, antibiotic sensitivities and treatment of these 15 patients were studied. Recommendations as a result of this study include the routine culture and sensitivity in otitis externa and where MRSA is cultured, a full contact history should be elicited and appropriate precautions taken. Specifically, a history of hospital contact should be sought. Treatments used successfully in the treatment of MRSA otitis externa were aural toilet and fucidic acid-betamathasone 0.5% wicks where the organism was gentamycin-resistant (GMRSA), whereas aural toilet with aminoglycoside-steroid drops was sufficient if it was gentamycin-sensitive.