Laboratory Testing of Ear Swabs in Otitis Externa

The microbiology department at Pathlab have been examining the clinical value of ear swabs for otitis externa in the community setting. There is a paucity of evidence to support the clinical usefulness of ear swabbing in otitis externa, and guidelines based on expert opinion do not recommend ear swabbing in uncomplicated otitis externa infection.

With this in mind, ear swabs in patients with clinically suspected otitis externa will only be accepted by the microbiology laboratory for processing if one of the following conditions apply and is documented on the request form: This will apply from Mon 6th May 2019.

• Recalcitrant otitis externa which has failed initial treatment with ear drops
• Recurrent or chronic (>2 weeks) otitis externa
• Topical treatment cannot be delivered effectively
• There is evidence the infection has extended beyond the external auditory canal (e.g. osteomyelitis, cellulitis, nerve palsy)
• The condition is complex/severe enough to warrant systemic antimicrobial treatment
• Presence of systemic symptoms (i.e. fever) or immunosuppression
• Request by ENT specialist

Clinical details that simply state “Otitis externa”, “Earache” or “Ear discharge”, will not be accepted.

Ear swabs from patients with otitis media (or clinical details that suggest middle ear infection such as “perforation with discharge”), children less than 5 years of age, or clinical details of “grommets” will all continue to be processed as normal.

Any ear swabs that are received without any clinical details will not be processed. Ear swabs that are not processed will be reported with a comment and will be discarded after 72 hours if appropriate clinical details are not received.

References:

• Ordering and interpreting ear swabs in otitis externa. BMJ 2014; 349
• Clinical Practice Guideline: Acute Otitis Externa. Rosenfeld, R. et al. Otolaryngology–Head and Neck Surgery, 2014, 150(1_suppl), S1–S24.
• BPAC: Antibiotics: Choices for common infections-Otitis Externa