The patient’s unmet needs (PUNs)
A 58-year-old man with diabetes presents with an itchy, discharging and mildly painful ear. He has experienced numerous episodes over the years. On examination, the external auditory meatus is inflamed and slightly swollen, and the drum is obscured by whitish exudate. As you’re pondering the most appropriate topical treatment – given that you’ve not had a good view of his tympanic membrane – he asks why he suffers repeated attacks and requires multiple visits before the problem settles.
The doctor’s educational needs (DENs)
What causes otitis externa?
Otitis externa is an inflammatory condition of the epithelium that lines the external auditory canal. It can be acute, chronic, diffuse or localised. Otitis externa can be the consequence of infection, allergy, trauma or a combination of all three.
What measures can be taken or advised to prevent recurrence?
In recurrent cases it is important to advise the patient to keep the ear dry.1 Patients should be educated not to instrument their ears with cotton buds, their fingers or indeed anything. Some patients benefit from the use of topical acetic acid as a preventive measure – a 2% preparation has been manufactured as a spray (EarCalm) and can be purchased without a prescription.
When the ear drum cannot be seen in a patient with a discharging ear, should the GP be wary of drops containing potentially ototoxic antibiotics?What topical treatment should be prescribed?
The use of aminoglycoside-containing eardrops in an ear where there is a perforation poses a potential risk of damage to the inner ear, and hearing loss and vertigo. In view of this, the British Association of Otorhinolaryngology – Head and Neck Surgery (now called ENT-UK) has produced national guidelines.2
The key recommendations for GPs are:
- When treating a patient with a discharging ear, in whom there is a perforation or patent grommet, a topical aminoglycoside should be used only in the presence of obvious infection.
- Topical aminoglycosides should be used for no longer than two weeks.
- The justification for using topical aminoglycosides should be explained to the patient.
- As vertigo is more common and presents earlier than the other features of ototoxicity, it is sensible to recommend that the patient stops applying ear drops if they begin to experience this symptom.
When are oral antibiotics needed? And how should the GP manage a case that is slow to settle?
Systemic antibiotics are unnecessary unless there is extension of the inflammation outside the ear canal (cellulitis), malignant otitis externa, if the patient is immunosuppressed, or if it is not possible to use a topical preparation.3
Apart from the administration of analgesia and topical ear drops, it is important to keep the ear canal free of debris to allow the ear drops to ‘work’. Cases that are slow to settle may be due to a fungal otitis externa. A swab of the ear canal is useful to identify the cause. If the patient has anything more than mild otitis externa and there are no facilities to perform microsuction, a referral to ENT is recommended. This can be arranged via a nurse-led aural care clinic, as well as via on-call junior doctors.
When should the GP suspect the more serious necrotising form of the disease?
Malignant (necrotising) otitis externa is more common in the immunocompromised patient, such as the elderly with diabetes. Granulation tissue may be seen arising from the external canal and the patient is often in extreme pain, especially at night. In severe cases, the patient may present with a cranial nerve palsy.
Suspected cases should be urgently referred to ENT.
Mr John Phillips is a consultant ENT surgeon at Norfolk and Norwich University Hospital Foundation Trust
References
1. McKean SA, Hussain SS. Otitis externa. Clin Otolaryngol. 2007;32(6):457-9.
2. Phillips JS, Yung MW, Burton MJ, Swan IRC. Evidence review and ENT-UK consensus report for the use of aminoglycoside-containing ear drops in the presence of an open middle ear. Clin Otolaryngol. 2007;32(5):330-6.
3. Rosenfeld RM, Schwartz SR, Cannon CR, Roland PS, Simon GR, Kumar KA, Huang WW, Haskell HW, Robertson PJ. Clinical practice guideline: acute otitis externa. Otolaryngol Head Neck Surg. 2014;150(1 Suppl):S1-S24.
