Otitis Externa

Overview

Otitis externa is inflammation and/or infection of the external ear canal. Patients commonly present with otalgia with or without ear discharge and hearing loss. Topical ear preparations are the mainstay of treatment and oral antibiotics are rarely indicated.

Most patients can be managed in primary care and further advice can be found on the BNSSG formulary primary care antimicrobial guidelines document, including advice on otc options and antibiotic prescribing.

You may also like to refer to the Clinical Knowledge Summary page on Otitis Externa.

Who to refer

If there are complications or persistent symptoms despite primary care management then consider the following pathways:

Discuss with ENT on call (via UHBW switchboard) if:

• Suspicion of necrotising otitis externa [see ‘red flag’ section]
• Severe regional spread of infection to pinna or face likely to require intravenous antibiotics

Refer to ENT HOT clinic if:

• Persistent symptoms despite management [see ‘before referral’ section]
• Confirmed fungal infection with copious discharge requiring microsuction
• Complete external ear canal occlusion preventing topical treatment (although consider discussion with ENT on call if symptoms are severe)

Refer to ENT Otology via eRS if:

• Chronic or recurrent otitis externa requiring 2-3 months of repeated topical treatment for symptoms

Consider ENT Advice and guidance if there are other concerns.

Red Flags

Necrotising otitis externa

Necrotising, or malignant, otitis externa is osteomyelitis of the temporal bone following external ear canal infection. Risk factors include older age, diabetes, and immunocompromise. Clinical symptoms and signs include:

• Unremitting and disproportionate otalgia, particularly overnight
• Systemically unwell and/or high fever
• Cranial nerve involvement, typically an ipsilateral facial nerve palsy
• Granulation tissue or exposed bone on the floor of the ear canal at the bone-cartilage junction

Other

• Systemically unwell and/or high fever
• Spreading erythema or swelling of the pinna or face

If suspected then discuss with  ENT on call (via UHBW switchboard).

Before referral

Investigations

Ear swabs for microbiology are rarely helpful in primary care and not indicated for non-complicated otitis externa.

Consider a swab of the external ear canal for MC&S if:

• Persistent symptoms after 14-days of treatment with appropriate topical ear preparation
• Suspicion of fungal infection
• Chronic otitis externa
• Referring a patient to ENT [see ‘who to refer’ section]

Treatment in Primary Care

All patients should be:

• offered analgesia for pain relief.
• advised to keep ear clean and dry.

Topical treatments should be used as guided by BNSSG antimicrobial guidelines:

• Mild cases: Topical Acetic acid 2% spray (Earcalm) - can be purchased otc.
• Moderate/severe cases: If infection is suspected use antibiotic/steroids drops. Full list of available drops is available on the ENT ear page of the BNSSG Fomulary*.
• If fungal infection is suspected then use a topical anti-fungal such as clotrimazole 1% solution (see antimicrobial guidelines and fungal infections subheading below)
• If eczematous otitis externa is not responding to acetic acid spray then consider topical steriods (without antbiotics to reduce risk of fungal infections).

Oral/systemic antibiotics should only be considered (in addition to topical therapy) for cases of infection outside of the ear canal (cellulitis) or the patient is immunocompromised.

*Note: ciprofloxacin containing drops including Ciprofloxacin 0.3% / Dexamethasone 0.1% (Cilodex), should be reserved for refractory cases or where there is concern about the presence of tympanic membrane perforation.

All cases of suspected malignant/necrotising externa should be referred to secondary care for urgent assessment (see red flags above)

Aminoglycoside drops - advice on use

Aminoglycoside drops are considered safe to use in patients with an intact tympanic membrance (2). However, the use of aminoglycoside containing drops in the presence of tympanic membrane perforation or a grommet is a grey area. Some ENT professionals still use them despite the risk of ototoxicity and this was endorsed by ENT-UK 2007 guidelines. However a more recent ENT UK Global Guideline on OE (9) (published March 2023) recommends ciprofloxacin if a perforation is present. The NICE CKS guidance (2) (published Feb 22) also suggest that ototoxic drops in patients with perforated TMs should only be used by specialists.

Fungal infections

Patients with a fungal ear infection may have; creamy white debris in the external ear canal, black or white fungal spores, used multiple antibiotics (topical or oral), or relevant risk factors including diabetes and immunocompromise.

If fungal infection is suspected, a swab of the external ear canal, specifically requesting to check for fungi, may be useful for confirmation. Consider prescribing anti-fungal preparations as advised by the BNSSG formulary. Anti-fungal preparations should continue for at least two weeks after the infection appears to have improved.

Resources

For patients:

https://patient.info/ears-nose-throat-mouth/earache-ear-pain/ear-infection-otitis-externa

https://www.nhs.uk/conditions/ear-infections/

For healthcare professionals:     

(1) 5. Infections Guidelines (Remedy BNSSG ICB)

(2) https://cks.nice.org.uk/topics/otitis-externa/

(3) https://www.entuk.org/resources/183/otitis_externa

(4) https://bnf.nice.org.uk/treatment-summaries/ear/

(5) https://www.bmj.com/content/372/bmj.n714

(6) https://journals.sagepub.com/doi/full/10.1177/17557380221136887

(7) https://bestpractice.bmj.com/topics/en-gb/40

(8) https://www.uptodate.com/contents/16516#

(9) Otitis externa - Global ENT Guideline | ENT UK

Efforts are made to ensure the accuracy and agreement of these guidelines, including any content uploaded, referred to or linked to from the system. However, BNSSG ICB cannot guarantee this. This guidance does not override the individual responsibility of healthcare professionals to make decisions appropriate to the circumstances of the individual patient, in consultation with the patient and/or guardian or carer, in accordance with the mental capacity act, and informed by the summary of product characteristics of any drugs they are considering. Practitioners are required to perform their duties in accordance with the law and their regulators and nothing in this guidance should be interpreted in a way that would be inconsistent with compliance with those duties.

Information provided through Remedy is continually updated so please be aware any printed copies may quickly become out of date.