INFECTIOUS DISEASES AND IMMUNIZATION COMMITTEE, CANADIAN PAEDIATRIC SOCIETY | 1

PRACTICE POINT

Acute otitis externaCharles PS Hui; Canadian Paediatric SocietyInfectious Diseases and Immunization CommitteePaediatr Child Health 2013;18(2):96-98Posted: Feb 1 2013

AbstractAcute otitis externa, also known as ‘swimmer’s ear’, is a common dis­ease of children, adolescents and adults. While chronic suppurative oti­tis media or acute otitis media with tympanostomy tubes or a perfora­tion can cause acute otitis externa, both the infecting organisms and management protocol are different. This practice point focuses solely on managing acute otitis externa, without acute otitis media, tympanos­tomy tubes or a perforation being present.

Key Words: Acute otitis externa; Swimmer’s ear

Acute otitis externa (AOE), also known as ‘swimmer’s ear’, is a common disease of children, adolescents and adults. It is defined by diffuse inflammation of the external ear canal. Pri­marily a disease of children over two years of age, it is com­monly associated with swimming. Local defence mechanisms become impaired by prolonged ear canal wetness. Skin desquamation leads to microscopic fissures that provide a portal of entry for infecting organisms.[1] Other risk factors for AOE include: trauma, a foreign body in the ear, using a hearing aid, certain dermatological conditions, chronic otor­rhea, wearing tight head scarves and being immunocompro­mised. Ear piercing may lead to infection of the pinna.[2][3]

While AOE is primarily a local disease, more serious and in­vasive disease can occur in certain situations. Several evi­dence-based clinical practice guidelines and reviews have been published.[4]-[8]

Clinical presentationTypically, patients present with otalgia (70%), itching (60%), or fullness (22%), with or without hearing loss (32%) or ear canal pain when chewing. Many patients with AOE have dis­charge from their ear canal. A distinguishing sign of AOE from acute otitis media with otorrhea is the finding of tender­ness of the tragus when pushed and of the pinna when pulled in AOE. These signs are classically described as out of propor­tion to the degree of inflammation observed. On direct oto­scopy, the canal is edematous and erythematous and may be associated with surrounding cellulitis.[4] There may be celluli­tis or chondritis of the pinna.

Elements to consider in the diagnosis of diffuse acute otitis externa:

1. Rapid onset (generally within 48 h) in the past three weeks

AND

2. Symptoms of ear canal inflammation, including

• otalgia (often severe), itching or fullness

• WITH OR WITHOUT hearing loss or jaw pain*

AND

3. Signs of ear canal inflammation, including

• tenderness of the tragus, pinna, or both

OR

• diffuse ear canal edema, erythema, or both

• WITH OR WITHOUT otorrhea, regional lymphadenitis, tympanic membrane erythema, or cellulitis of the pinna and adjacent skin

*Pain in the ear canal and temporomandibular joint region intensified by jaw motion [4]

Etiological organismsInfection causes the vast majority of AOE cases. The two most commonly isolated organisms are Pseudomonas aerugi­

nosa and Staphylococcus aureus.[9] The isolates are polymicro­bial in a significant number of cases. Other Gram-negative bacteria are less common. Rare fungal infections have been described with Aspergillus species and Candida species.[10]

Swabs from the external canal should be interpreted with caution because they may reflect normal flora or colonizing organisms. Swabs should be taken only in unresponsive or se­vere cases.

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ManagementThe management of AOE has been the subject of one Cochrane systematic review (updated 2010) [8], one meta-analysis by the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS),[11] and one clinical practice guideline (AAO-HNS).[4] The Cochrane publication reviewed 19 studies that included 3382 participants. Overall, only three of the 19 studies were considered to be of high quality and only two were done in a primary care setting. Similar findings were reached in the AAO-HNS meta-analysis and are reflected in the practice guideline.

It is clear that topical antimicrobials are effective in mild-to-moderate AOE. No randomized control trials have been pub­lished comparing topical to systemic antimicrobials. Topical antimicrobials increased absolute clinical cure rates of AOE by 46% and bacteriological cure rates by 61% compared with placebo.[11] There seemed to be minimal to no difference in clinical or bacteriological cure rate for the addition of topical steroids to topical antimicrobials, although the quality of these studies was poor.[4][12] A systematic review showed that in a combined total of only 92 patients there was a slight su­periority of topical steroids compared with topical steroids and topical antimicrobials for clinical cure at seven to 11 days. Topical acidifying solutions (eg, Buro-Sol) have also been shown to be equally effective as topical antimicrobials in clinical cure rates at one week, but inferior in clinical and mi­crobiological cure at two to three weeks. Topical antiseptics such as alcohol, gentian violet, m-Cresyl acetate, thimerosal and thymol have been shown in small studies to be equally ef­fective as topical antimicrobials but are not specifically mar­keted in Canada for treatment of AOE.

Ototoxic topical agents such as gentamicin or neomycin, agents with a low pH (including most acidifying and antisep­tic agents), or Cortisporin (Johnson & Johnson Inc., USA) topical drops should not be used in the presence of tympa­nostomy tubes or a perforated tympanic membrane because there is an increasing body of literature concerning ototoxici­ty in both settings.[13] These agents should also not be used if the tympanic membrane cannot be seen.

For treating mild-to-moderate acute otitis externa, the follow­ing steps are recommended:

1. First line therapy for mild-to-moderate AOE should be a topical antibiotic with or without topical steroids for sev­en to 10 days.[4] More severe cases should be managed with systemic antibiotics that cover S aureus and P aerug­

inosa.

2. Adequate pain control for mild-to-moderate AOE can be achieved with systemic acetaminophen, non-steroidal anti-inflammatory medications or oral opioid prepara­tions. Topical steroid preparations have had mixed ef­fects on hastening pain relief in clinical trials and can­not be recommended as monotherapy.

3. If the clinician cannot see the ear canal, an expandable wick can be placed to decrease canal edema and facili­tate topical medication delivery.[14] Although aural toilet­ing and wick therapy are common and logical practices, there have been no randomized controlled trials examin­ing their effectiveness. Ear candling has been shown to have no efficacy and can be harmful.[15]

Clinical response should be evident within 48 h to 72 h [16]

but full response can take up to six days in patients treated with antibiotic and steroid drops.[8] Nonresponse should prompt an evaluation for obstruction, the presence of a for­eign body, non-adherence to therapy or an alternative diagno­sis (eg, dermatitis from contact with nickel, a viral or fungal infection or antimicrobial resistance).

Malignant otitis externaIn patients who are immunodeficient or who have insulin-de­pendent diabetes, special measures should be taken to rule out malignant otitis externa. This invasive infection of the cartilage and bone of the canal and external ear may present with facial nerve palsy and pain as a prominent symptom. Imaging with a computed tomography or magnetic resonance imaging scan may be needed to confirm the clinical diagno­sis.[17] Aggressive debridement with systemic antibiotics target­ed at P aeruginosa, and in some cases Aspergillus species, is crit­ical.

PreventionTargeting typical causal culprits of AOE, such as moisture and trauma, seems prudent. Some experts recommend simple techniques for keeping water out of the ears (eg, inserting a soft, malleable plug into the auricle to block entry to the ear canal) or removing water from the ears after swimming (by positioning or shaking the head, or by using a hair dryer on a low setting). Others advise avoiding cotton swabs because they might impact cerumen. Daily prophylaxis with alcohol or acidic drops during at-risk activities has also been suggest­ed but not studied. Using hard earplugs should be avoided because they can cause trauma, and the use of custom ear canal molds and tight swim caps remains controversial.[5]

INFECTIOUS DISEASES AND IMMUNIZATION COMMITTEE, CANADIAN PAEDIATRIC SOCIETY | 3

TABLE 1Medications available in Canada for acute otitis externa

Brand name Active ingredients Dosing and duration as per the product monograph

Polysporin plus pain

relief ear drops*,†Polymyxin B sulphate –lidocaine HCl

Three to four drops four times/dayInfants and children, two to three drops are suggested.Solution may be applied by saturating a gauze or cotton wick which may be left in the canal for 24 h to 48 h, keeping the wick moist by adding a few drops of solution as required.No duration stated

Polysporin eye/ear

drops*,†Polymyxin B sulphate – gramicidin

One to two drops four times/day, or more frequent as requiredNo duration stated

Neosporin eye and

ear solution*,‡Polymyxin B sulphate – neomycin sulphate –gramicidin

One to two drops two to four times/day for seven days

Cortisporin otic

solution sterile*,†,§Neomycin sulphate – polymyxin B sulfate –hydrocortisone

Four drops three to four times/dayNo duration stated

Sofracort*,¶ Framycetin sulfate – grami­cidin – dexamethasone

Two to three drops three to four times/dayNo duration stated

Ciprodex** Ciprofloxacin HCI –dexamethasone

Four drops twice/day for seven days

Buro-Sol otic solu­

tion*,††,‡‡Aluminum acetate –benzethonium chloride – acetic acid

Two to three drops three to four times/dayNo duration stated

Garasone otic solu­

tion*,§§Gentamicin – betametha­sone

Three to four drops three times/dayNo duration stated

Garamycin otic

drops*,‡‡Gentamicin sulfate Three to four drops three times/day

No duration stated

* Should not be used in patients with a non-intact tympanic membrane; †Johnson & Johnson Inc., USA; ‡GlaxoSmithKline, UK; §sanofi-aventis Canada Inc.; ¶Alcon Canada Inc.;**Off-label use;†† Stiefel Canada Inc.; ‡‡Merck Canada Inc.; §§Schering Canada Inc.

AcknowledgementsThis practice point has been reviewed by the Community Paediatrics and Drug Therapy and Hazardous Substances Committees of the Canadian Pae­diatric Society.

References1. Wright DN, Alexander JM. Effect of water on the bacterial flo­

ra of swimmer’s ears. Arch Otolaryngol 1974;99(1):15-8.2. Rowshan HH, Keith K, Baur D, Skidmore P. Pseudomonas

aeruginosa infection of the auricular cartilage caused by "high ear piercing": A case report and review of the literature. J Oral Maxillofac Surg 2008;66(3):543-6.

3. Keene WE, Markum AC, Samadpour M. Outbreak of Pseudomonas aeruginosa infections caused by commercial piercing of upper ear cartilage. JAMA 2004 25;291(8):981-5.

4. Rosenfeld RM, Brown L; American Academy of Otolaryngolo­gy--Head and Neck Surgery Foundation, et al. Clinical practice guideline: Acute otitis externa. Otolaryngol Head Neck Surg 2006;134(4 Suppl): S4-23.

5. Osguthorpe JD, Nielsen DR. Otitis externa: Review and clini­cal update. Am Fam Physician 2006;74(9):1510-6.

6. McKean SA, Hussain SSM. Otitis externa. Clinical Otolaryn­gology 2007;32(6):457-9.

7. Stone KE, Serwint JR. Otitis externa. Pediatr Rev 2007;28(2):77-8.

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8. Kaushik V, Malik T, Saeed SR. Interventions for acute otitis ex­terna. Cochrane Database Syst Rev 2010:1: CD004740.

9. Roland PS, Stroman DW. Microbiology of acute otitis externa. Laryngoscope 2002;112(7):1166-77.

10. Martin TJ, Kerschner JE, Flanary VA. Fungal causes of otitis ex­terna and tympanostomy tube otorrhea. Int J Pediatr Otorhino­laryngol 2005;69(11):1503-8.

11. Rosenfeld RM, Singer M, Wasserman JM, Stinnett SS. System­atic review of topical antimicrobial therapy for acute otitis ex­terna. Otolaryngol Head Neck Surg 2006;134(4 Suppl):S24-48.

12. Mösges R, Domröse CM, Löffler J. Topical treatment of acute otitis externa: Clinical comparisonof an antibiotics ointment alone or in combination with hydrocortisone acetate. Eur Arch Otorhinolaryngol 2007;264(9):1087-94.

13. Stockwell, M. Gentamicin ear drops and ototoxicity: Update CMAJ 2001;164(1):93-4.

14. Otitis externa. In Cummings CW, Flint PW, Haughey BH, et al. Otolaryngology: Head and Neck Surgery, 4th edn. Philadel­phia, PA: Mosby, 2005.

15. Seely DR, Quigley SM, Langman AW. Ear candles: Efficacy and safety. Laryngoscope 1996;106(10):1226–9.

16. van Balen FA, Smit WM, Zuithoff NP, Verheij TJ. Clinical effi­cacy of three common treatments in acute otitis externa in pri­mary care: Randomised controlled trial. BMJ 2003;327(7425):1201-5.

17. Rubin Grandis J, Branstetter BF 4th, Yu VL. The changing face of malignant (necrotizing) external otitis: Clinical, radio­logical, and anatomic correlations. Lancet Infect Dis 2004;4(1):34-9.

CPS INFECTIOUS DISEASES AND IMMUNIZATION COMMIT-TEE

Members: Robert Bortolussi MD; Natalie A Bridger MD; Jane C Finlay MD; Susanna Martin MD (Board Representative); Jane C McDonald MD; Heather Onyett MD; Joan Louise Robinson MD (Chair)Liaisons: Upton D Allen MD, Canadian Pediatric AIDS Research Group; Michael Brady MD, Committee on Infectious Diseases, American Academy of Pediatrics; Janet Dollin MD, College of Family Physicians of Canada; Charles PS Hui MD, Committee to Advise on Tropical Medicine and Trav-el, Public Health Agency of Canada; Nicole Le Saux MD, Immunization Monitoring Program, ACTive (IMPACT); Dorothy L Moore MD, National Advisory Committee on Immunization (NACI);  John S Spika MD, Public Health Agency of CanadaConsultant: Noni E MacDonald MDPrincipal author: Charles PS Hui MD

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Disclaimer: The recommendations in this position statement do not indicate an exclusive course of treatment or procedure to be followed. Variations, taking in­to account individual circumstances, may be appropriate. Internet addresses are current at time of publication.