Otitis externa

Disclaimer These guidelines have been produced to guide clinical decision making for the medical, nursing and allied health staff of Perth Children’s Hospital. They are not strict protocols, and they do not replace the judgement of a senior clinician. Clinical common-sense should be applied at all times. These clinical guidelines should never be relied on as a substitute for proper assessment with respect to the particular circumstances of each case and the needs of each patient. Clinicians should also consider the local skill level available and their local area policies before following any guideline.  Read the full CAHS Clinical disclaimer

Aim 

To guide PCH ED staff with the assessment and management of otitis externa in children who present to the Emergency Department.

Definition

Otitis externa is an infection of the external ear canal. It is also referred to as 'swimmer's ear'.

Background^1,2,3

The ear canal guards against infection by producing a protective layer of cerumen (ear wax), which creates an acidic and lysozyme-rich environment. While a paucity of cerumen allows for bacterial growth, an excess can cause retention of water and debris, which can create an ideal environment for bacterial invasion.

• Otitis externa is a common cause of ear pain
• It has a lifetime incidence of 10%
• Peak incidence is in children aged 7-12 years
• It presents more often in summer months when swimming is more common
• It may be secondary to atopic dermatitis, trauma to the ear canal or discharging otitis media
• The organisms involved include Staphylococcus aureus,Pseudomonas and fungi (e.g. Aspergillus^)4. Infections with Candida are less common. 

Assessment^2,3

• Key features include ear pain and discharge
• No investigations are generally required. However, consider ear swabs if recurrent episodes or no response to treatment.

History^2,3

Common symptoms of otitis externa are:

• Ear pain
• Conductive hearing loss
• Feeling of fullness (blockage) or pressure
• Itchiness
• +/- discharge.

Examination^2,3

• The tragus and pinna are exquisitely tender when moved
• The ear canal may be erythematous and dry, or it may have grey or black fungal plaques that resemble fuzzy cotton wool
• It is most commonly moist and oedematous, and the narrowed ear canal is filled with serous or purulent debris
• Fungal infection is suggested by a 'wet newspaper' appearance
• Cerumen (ear wax) is characteristically absent
• By definition, cranial nerve (CN) involvement (i.e. of the CN’s VII and IX-XII) is not associated with simple otitis externa
• Inspect the ear for any foreign body.

Investigations

Ear swabs are not required for simple otitis externa, they are unhelpful as the organisms grown on culture may or may not be true pathogens.

Ear swabs should be performed for patients with recurrent otitis externa, who are immunocompromised or did not respond to treatment.

Differential diagnoses

• Otitis media with rupture of the tympanic membrane.

Management^3,4

• Analgesia is the most important aspect of management.
• Topical treatment should be used instead of oral antibiotics (topical antibacterial/corticosteroid combinations are usually first line).

Initial management^3,4

Analgesia

• Oral paracetamol or ibuprofen

Ear Toilet

• Discharge or other debris should be removed from the ear canal by dry aural toilet.

Ear Drops

• Instil a combination antimicrobial / corticosteroid ear drop
  • Kenacomb otic ^® / Otocomb Otic ^® if fungal infection suspected
  • Sofradex^®, Otodex^® for bacterial infection. Refer to Ear, Nose, Throat and Dental Infections: Paediatric Empiric Guidelines - ChAMP
• If the ear canal is not too narrow to allow medication to flow freely, instil drops directly
• If the ear canal is blocked, insert a dry ear wick and then instil drops down the wick every 6-8 hours. Review and replace wick in 48 hours.

Keep ear dry

• Soft wax earplugs should be used when showering
• No swimming.

Persisting infection which is thought to be fungal can be treated with Locacorten-Viaform ear drops, where as more severe cases may require a topical antifungal such as 1% clotrimazole.

Oral antibiotics are not routinely used for simple otitis externa.

Oral antibiotics may be required for complicated otitis externa (e.g. with significant cellulitis, or symptoms such as fever or cervical lymphadenopathy).

Further management

• Following treatment, prophylaxis with 2% acetic acid drops (e.g. Aqua-ear) should be instilled after swimming and showering. These drops can also be used to prevent recurrences. Contraindicated in perforated tympanic membrane.

Complications

• Furunculosis of the externa ear is the development of a furuncle (boil) in the outer part of the ear canal and causes extreme pain. Management is with adequate analgesia and systemic (oral) antibiotics (flucloxacillin).
• Cellulitis of the surrounding tissue requires similar treatment.

Bibliography

1. Clarke RC. Pediatric Otolaryngology Practical Clinical Management. July 2017
2. Shaw KN & Bachur RG. Fleisher & Ludwig’s Textbook of Pediatric Emergency Medicine. 8th ed. Philadelphia: Lippincott Williams & Wilkins, 2020.
3. Rosenfeld RM, Schwartz SR, Cannon CR, Roland PS, Simon GR, Kumar KA, et al. Clinical practice guideline: acute otitis externa. Otolaryngol Head Neck Surg 2014;150(1 Suppl):S1–S24
4. Acute diffuse otitis externa Topic | Therapeutic Guidelines (health.wa.gov.au) March 2021

Endorsed by:	Nurse, Co-director, Surgical Services	Date:	Feb 2023
		Review date:	Jan 2026

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