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Home , Otitis, Otitis externa

Acute Externa: An Update PAUL SCHAEFER, MD, PhD, and REGINALD F. BAUGH, MD, University of Toledo College of Medicine, Toledo, Ohio

Acute is a common condition involving of the canal. The acute form is caused pri- marily by bacterial , with and the most common patho- gens. Acute otitis externa presents with the rapid onset of inflammation, resulting in otalgia, itching, canal , canal erythema, and otorrhea, and often occurs following swimming or minor trauma from inappropriate cleaning. Tenderness with movement of the or pinna is a classic finding. Topical antimicrobials or antibiot- ics such as , aminoglycosides, polymyxin B, and quinolones are the treatment of choice in uncomplicated cases. These agents come in preparations with or without topical ; the addition of corticosteroids may help resolve symptoms more quickly. However, there is no good evidence that any one antimicrobial or preparation is clinically superior to another. The choice of treatment is based on a number of factors, including tym- panic membrane status, adverse effect profiles, adherence issues, and cost. Neomycin/polymyxin B/hydrocortisone preparations are a reasonable first-line therapy when the tympanic membrane is intact. Oral are reserved for cases in which the infection has spread beyond the ear canal or in patients at risk of a rapidly progressing infec- tion. Chronic otitis externa is often caused by or underlying inflammatory dermatologic conditions, and is treated by addressing the underlying causes. (Am Fam Physician. 2012;86(11):1055-1061. Copyright © 2012 Ameri- can Academy of Family Physicians.) ▲ Patient information: titis externa, also called swim- occasions, the infection invades the surround- A handout on this topic is mer’s ear, involves diffuse inflam- ing soft tissue and bone; this is known as available at http://family doctor.org/657.xml. mation of the external ear canal malignant (necrotizing) otitis externa, and is that may extend distally to a medical emergency that occurs primarily in O the pinna and proximally to the tympanic older patients with mellitus.3 Otitis membrane. The acute form has an annual externa lasting three months or longer, known incidence of approximately 1 percent1 and a as chronic otitis externa, is often the result of lifetime prevalence of 10 percent.2 On rare allergies, chronic dermatologic conditions, or inadequately treated acute otitis externa.

Etiology Table 1. Predisposing Factors for Otitis Externa In North America, 98 percent of cases of acute otitis externa are caused by bacteria.4 Anatomic abnormalities Dermatologic conditions The two most common isolates are Pseudo- Canal stenosis Eczema monas aeruginosa and Staphylococcus aureus. Exostoses However, a wide variety of other aerobic Hairy ear canals Seborrhea and anaerobic bacteria have been isolated.5,6 Canal obstruction Other inflammatory dermatoses Approximately one-third of cases are polymi- Cerumen obstruction Water in ear canal crobial.4 Fungal , primarily those Foreign body Humidity of the and Candida species, occur Sebaceous cyst Sweating more often in tropical or subtropical environ- Cerumen/epithelial integrity Swimming or other prolonged ments and in patients previously treated with Cerumen removal water exposure antibiotics.7-9 Inflammatory skin disorders Miscellaneous and allergic reactions may cause noninfec- Hearing aids Purulent otorrhea from tious otitis externa, which can be chronic. Instrumentation/itching Soap Stress Risk Factors Type A blood Several factors may predispose patients Information from references 4 and 10. to the development of acute otitis externa (Table 1).4,10 One of the most common

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Evidence Clinical recommendation rating References Comments

Acute otitis externa should be distinguished from C 4 Different and overlapping pathologies may other possible causes of ear canal inflammation. require alteration in treatment Topical antimicrobial otic preparations should A 4, 14-16 Choose specific preparation based on risk of be considered the first-line treatment for adverse effects, tympanic membrane status, uncomplicated acute otitis externa. cost, adherence issues, etc. Addition of a topical may result B 4, 14-16 May be partly dependent on strength of in faster resolution of symptoms such as , corticosteroid canal edema, and canal erythema. Systemic antibiotics should be used only if the B 4, 14, 16 — infection has spread beyond the ear canal or in patients at high risk of such spread. Use of aural toilet should be considered to remove C 4, 16 Widely performed in research studies, but no debris from the ear canal before treatment. data on effectiveness

A = consistent, good-quality patient-oriented evidence; B = inconsistent or limited-quality patient-oriented evidence; C = consensus, disease- oriented evidence, usual practice, expert opinion, or case series. For information about the SORT evidence rating system, go to http://www.aafp. org/afpsort.xml.

predisposing factors is swimming, espe- lowest settings and head tilting to remove cially in fresh water. Other factors include water from the ear canal, and avoidance of skin conditions such as eczema and sebor- self-cleaning or scratching the ear canal. rhea, trauma from cerumen removal, use of Acetic acid 2% (Vosol) otic solutions are also external devices such as hearing aids, and used, either two drops twice daily or two to cerumen buildup.4 These factors appear to five drops after water exposure. However, no work primarily through loss of the protec- randomized trials have examined the effec- tive cerumen barrier, disruption of the epi- tiveness of any of these measures. thelium (including maceration from water retention), inoculation with bacteria, and Diagnosis increase in the pH of the ear canal.10-12 Acute otitis externa is diagnosed clinically based on of canal Prevention inflammation (Table 2 4; Figures 1 and 2). A number of preventive measures have been Presentation can range from mild discom- recommended, including use of earplugs fort, itching, and minimal edema to severe while swimming, use of hair dryers on the pain, complete canal obstruction, and involvement of the pinna and surrounding skin. Pain is the symptom that best corre- Table 2. Diagnosis of Otitis Externa lates with the severity of disease.13 Mild may be present, but a temperature greater Onset of symptoms within 48 hours in the past three weeks than 101°F (38.3°C) suggests extension and beyond the auditory canal. Symptoms of ear canal inflammation: Acute otitis externa should be distinguished , itching, or fullness from other causes of ear canal inflamma- With or without or jaw pain tion4 (Table 3; see previous AFP article on ear and pain [http://www.aafp.org/afp/2008/0301/ Signs of ear canal inflammation: p621.html]). Proper evaluation includes a Tenderness of tragus/pinna or ear canal edema/erythema history of presenting and associated symp- With or without otorrhea, tympanic membrane erythema, of toms, water exposure, local trauma/cerumen the pinna, or local lymphadenitis removal, inflammatory skin disorders, dia- betes, ear surgeries, and local radiotherapy. Adapted with permission from Rosenfeld RM, Brown L, Cannon CR, et al.; American Academy of Otolaryngology–Head and Neck Surgery Foundation. Clinical practice Physical examination should include the guideline: acute otitis externa. Otolaryngol Head Neck Surg. 2006;134(4 suppl):S5. and surrounding lymph nodes, a skin examination, otoscopy of the ear canal, and

1056 American Family Physician www.aafp.org/afp Volume 86, Number 11 ◆ December 1, 2012 Figure 1. Otitis externa on otoscopic exami- nation following debris removal. Note canal Figure 2. Acute otitis externa on otoscopic erythema and edema. examination. Note marked canal edema.

Table 3. Conditions That May Be Confused with Acute Otitis Externa

Condition Distinguishing characteristics Comment

Acute otitis media Presence of effusion, no tragal/pinnal Use or , treat tenderness with systemic antibiotics Chronic otitis Itching is often predominant symptom, Treat underlying causes/conditions externa erythematous canal, lasts more than three months Chronic suppurative Chronic otorrhea, nonintact tympanic membrane Control otitis externa symptoms, then treat otitis otitis media media Contact Allergic reaction to materials (e.g., metals, soaps, Check for piercings, hearing aids, or use; plastics) in contact with the skin/epithelium; discontinue exposure when possible itching is predominant symptom Eczema Itching is predominant symptom; often chronic; Consider treatment with topical corticosteroids history of atopy, outbreaks in other locations Furunculosis Focal infection, may be pustule or nodule, often in Consider treatment with heat, incision and distal canal drainage, or systemic antibiotics; can progress to diffuse otitis externa Malignant otitis High fever, granulation tissue or necrotic tissue in ear Medical emergency with high morbidity rate externa canal, may have cranial nerve involvement; patient and possible mortality; warrants emergent with diabetes mellitus or immunocompromise, consultation with otolaryngologist, elevated erythrocyte sedimentation rate, findings hospitalization, intravenous antibiotics, on computed tomography debridement Myringitis Tympanic membrane inflammation, may have Usually results from acute otitis media or viral vesicles; pain is often severe, no canal edema infection Itching is predominant symptom, thick material in Can coexist with bacterial ; treat with acetic canal, less edema; may see fungal elements on acid (Vosol), half acetic acid/half alcohol, or topical otoscopy (Figures 3 and 4) antifungals; meticulous cleaning of ear canal Ramsay Hunt Herpetic ulcers in canal; may have facial numbness/ Treatment includes antivirals, systemic syndrome paralysis, severe pain, loss of taste corticosteroids Referred pain Normal ear examination Look for other causes based on patterns of referred pain

Seborrhea Itching and rash on hairline, face, scalp Treatment includes lubricating or moisturizing the external auditory canal

Sensitization to Severe itching, maculopapular or erythematous Type IV delayed hypersensitivity reaction to otics rash in conchal bowl and canal; may have streak neomycin or other components of otic solutions; on pinna where preparation contacted skin; discontinue offending agent; treat with topical vesicles may be present corticosteroids Figure 3. Otomycosis caused by Candida. Note Figure 4. Otomycosis caused by Aspergillus. the characteristic white fungal elements on Note the characteristic gray-black fungal ele- the debris. ments on the debris.

verification that the tympanic membrane is absolute increase in clinical cure rate of 46 intact. Tenderness with movement of the tra- percent or a number needed to treat of slightly gus or pinna is a classic finding. more than two.4,14-16 Topical agents come in a Because otitis externa can cause tympanic variety of preparations and combinations; a membrane erythema, pneumatic otoscopy or recent systematic review included 26 differ- tympanometry should be used to differenti- ent topical interventions.15 In some studies, ate it from otitis media. Otomycosis is classi- ophthalmic preparations have been used off- cally associated with itching, thick material label to treat otitis externa.14,15 Ophthalmic in the ear canal, and failure to improve with preparations may be better tolerated than use of topical antibacterials. Otomycosis can otic preparations, possibly due to differences sometimes be identified during otoscopy in pH between the preparations, and may (Figures 3 and 4), although nonpathogenic help facilitate compliance with treatment saprophytic fungi may also be found. recommendations. Commonly studied anti- Malignant otitis externa may be suspected microbial agents include aminoglycosides, in older patients with diabetes mellitus polymyxin B, quinolones, and acetic acid. or immunocompromise who have refrac- No consistent evidence has shown that any tory purulent otorrhea and severe otalgia one agent or preparation is more effective that may worsen at night. Clinical findings than another.4,14-16 There is limited evidence include granulation tissue in the external that use of acetic acid alone may require auditory canal, especially at the bone-car- two additional days for resolution of symp- tilage junction. Extension of the infection toms compared with other agents, and that beyond the auditory canal can cause lymph- it is less effective if treatment is required for adenopathy, , and and more than seven days.15 other cranial nerve palsies. Current guidelines recommend factor- In chronic otitis externa, the symptoms ing in the risk of adverse effects, adherence and signs listed in Table 2 4 occur for more issues, cost, patient preference, and physi- than three months. Classic symptoms include cian experience. Some components found in itching and mild discomfort; there may also otic preparations may cause contact derma- be lichenification on otoscopy. titis.17 Hypersensitivity to aminoglycosides, particularly neomycin, may develop in up to Treatment 15 percent of the population, and has been TOPICAL MEDICATIONS identified in approximately 30 percent of Topical antimicrobials, with or without topi- patients who also have chronic or eczema- cal corticosteroids, are the mainstay of treat- tous otitis externa.17,18 Adherence to topical ment for uncomplicated acute otitis externa. therapy increases with ease of administra- Topical antimicrobials are highly effective tion, such as less frequent dosing.19 The addi- compared with placebo, demonstrating an tion of a topical corticosteroid yields more

1058 American Family Physician www.aafp.org/afp Volume 86, Number 11 ◆ December 1, 2012 Acute Otitis Externa

rapid improvement in symptoms such as patients who have mild symptoms of otitis pain, canal edema, and erythema.4,14-16 Cost externa. If the tympanic membrane is intact varies considerably for the different prepara- and there is no concern of hypersensitivity to tions20,21 (Table 4 4,14-16,20,21). aminoglycosides, a neomycin/polymyxin B/ hydrocortisone otic preparation would be a ORAL ANTIBIOTICS first-line therapy because of its effectiveness Systemic antibiotics increase the risks of and low cost. and / adverse effects, generation of resistant organ- dexamethasone (Ciprodex) are approved isms, and recurrence. They also increase time for middle ear use and should be used if the to clinical cure and do not improve outcomes tympanic membrane is not intact or its status compared with a topical agent alone in uncom- cannot be determined visually 4; these also plicated otitis externa.1,6,16,22 Systemic antibiot- may be useful if patients are hypersensitive to ics should be used only when the infection has neomycin, or if nonadherence to treatment spread beyond the ear canal, or when there is because of dosing frequency is an issue. Use uncontrolled diabetes, immunocompromise, of a corticosteroid-containing preparation is a history of local radiotherapy, or an inability recommended to provide more rapid relief to deliver topical antibiotics.4,14,16 when symptoms warrant. Patients should be taught to properly TREATMENT METHODS administer otic medications. The patient Use of a topical otic preparation without cul- should lie down with his or her affected side ture is a reasonable treatment approach for facing upward, running the preparation along

Table 4. Common Antimicrobial Otic Preparations for Otitis Externa

Use if tympanic membrane Component Cost of generic (brand) Dosage perforation? Comments

Acetic acid 2% (Vosol) $39 for 15 mL* Four to six No May cause pain and irritation; ($36 for 15 mL)* times daily may be less effective than other treatments if use is required beyond one week; often used as prophylactic agent

Ciprofloxacin 0.3%/ Not available Twice daily Yes Low risk of sensitization dexamethasone 0.1% ($160 for 7.5 mL)* (Ciprodex)

Hydrocortisone 2%/acetic $220 for 10 mL† Four to six No May cause pain and irritation acid 1% (Vosol HC) ($215 for 10 mL)* times daily

Neomycin/polymyxin B/ $28 for 10-mL solution; Three to No Ototoxic; higher risk of contact hydrocortisone, solution $30 for 10-mL suspension† four times hypersensitivity; avoid in or suspension ($85 for 10-mL solution; daily chronic/eczematous otitis $78 for 10-mL suspension)† externa4

Ofloxacin 0.3% $60 for 5 mL; $93 for 10 mL† Once to Yes Low risk of sensitization ($80 for 5 mL; $143 for twice daily 10 mL)†

*—Estimated retail price of one course of treatment (10 to 14 days) based on information obtained at Red Book Online at http://aapredbook. aappublications.org (accessed April 5, 2012). †—Estimated retail price of one course of treatment (10 to 14 days) based on information obtained at http://www.drugstore.com (accessed April 5, 2012). Information from references 4, 14 through 16, 20, and 21.

December 1, 2012 ◆ Volume 86, Number 11 www.aafp.org/afp American Family Physician 1059 Acute Otitis Externa

the side of the ear canal until it is full and gen- that such material be removed to achieve tly moving the pinna to relieve air pockets. optimal effectiveness of the topical antibiot- The patient should remain in this position for ics.4,16 However, no randomized controlled three to five minutes, after which the canal trials have examined the effectiveness of should not be occluded, but rather left open to aural toilet, and this is not typically done dry.4 It may benefit the patient to have another in most primary care settings.4,15 Topical person administer the ear drops, because only medications rely on direct contact with the 40 percent of patients self-medicate appropri- infected skin of the ear canal; hence, aural ately.23 Patients should be instructed to mini- toilet takes on greater importance when the mize trauma to (and manipulation of) the volume or thickness of the debris in the ear ear, and to avoid water exposure, including canal is great. Guidelines recommend aural abstinence from water sports for a week or, at toilet by gentle lavage suctioning or dry minimum, avoidance of submersion. mopping under otoscopic or microscopic When there is marked canal edema, a visualization to remove obstructing material wick of compressed cellulose or ribbon and to verify tympanic membrane integrity.4 gauze may be placed in the canal to facilitate Lavage should be used only if the tympanic antimicrobial or antibiotic administration. membrane is known to be intact, and should Wick placement permits antibiotic drops not be performed on patients with diabe- to reach portions of the external auditory tes because of the potential risk of causing canal that are inaccessible because of canal malignant otitis externa.4 Pain medications swelling. As the canal responds to treatment may be required during the procedure. and patency returns to the ear canal, the wick often falls out. CHRONIC OTITIS EXTERNA The treatment of chronic otitis externa ANALGESIA depends on the underlying causes. Because Pain is a common symptom of acute otitis most cases are caused by allergies or inflam- externa, and can be debilitating.12 Oral anal- matory dermatologic conditions, treatment gesics are the preferred treatment. First-line includes the removal of offending agents include nonsteroidal and the use of topical or systemic corticoste- anti-inflammatory drugs and roids. Chronic or intermittent otorrhea over Systemic antibiotics are acetaminophen. When ongo- weeks to months, particularly with an open appropriate for acute otitis ing frequent dosing is required tympanic membrane, suggests the presence externa only in certain to control pain, medications of chronic suppurative otitis media. Initial conditions (e.g., infection should be administered on treatment efforts are similar to those for acute beyond the ear canal, uncon- a scheduled rather than as- otitis media. With control of the symptoms of trolled diabetes, inability to needed basis. Opioid combi- otitis externa, attention can shift to the man- use topical antibiotics). nation pills may be used when agement of chronic suppurative otitis media. symptom severity warrants. otic preparations may com- Follow-up and Referral promise the effectiveness of otic antibiotic Most patients will experience considerable drops by limiting contact between the drop improvement in symptoms after one day of and the ear canal. The lack of published data treatment. If there is no improvement within supporting the effectiveness of topical ben- 48 to 72 hours, physicians should reevalu- zocaine preparations in otitis externa limits ate for treatment adherence, misdiagnosis the role of such treatments. (Table 3), sensitivity to ear drops, or con- tinued canal patency. The physician should CLEANING THE CANAL consider culturing material from the canal Acute otitis externa can be associated with to identify fungal and antibiotic-resistant copious material in the ear canal. Consen- pathogens if the patient does not improve sus guidelines published by the American after initial treatment efforts or has one or Academy of Otolaryngology recommend more predisposing risk factors, or if there

1060 American Family Physician www.aafp.org/afp Volume 86, Number 11 ◆ December 1, 2012 Acute Otitis Externa

is suspicion that the infection has extended Foundation. Clinical practice guideline: acute oti- tis externa. Otolaryngol Head Neck Surg. 2006;134 beyond the external auditory canal. There is a (4 suppl):S4-S23. lack of data regarding optimal length of treat- 5. Ninkovic G, Dullo V, Saunders NC. Microbiology of ment; as a general rule, antimicrobial otics otitis externa in the secondary care in United King- should be administered for seven to 10 days, dom and antimicrobial sensitivity. Auris Nasus Larynx. although in some cases complete resolution of 2008;35(4):480-484. 4,15 6. Roland PS, Stroman DW. Microbiology of acute otitis symptoms may take up to four weeks. externa. Laryngoscope. 2002;112(7 pt 1):1166 -1177. Consultation with an otolaryngologist 7. Martin TJ, Kerschner JE, Flanary VA. Fungal causes of or infectious disease subspecialist may be otitis externa and tympanostomy tube otorrhea. Int warranted if malignant otitis externa is J Pediatr Otorhinolaryngol. 2005;69(11):1503-1508. suspected; in cases of severe disease, lack 8. Pontes ZB, Silva AD, Lima Ede O, et al. Otomycosis: a retrospective study. Braz J Otorhinolaryngol. 2009; of improvement or worsening of symptoms 75(3):367-370. despite treatment, and unsuccessful lavage; 9. Ahmad N, Etheridge C, Farrington M, Baguley DM. Pro- or if the primary care physician determines spective study of the microbiological flora of moulds and the efficacy of current cleaning tech- that aural toilet or ear wick insertion is war- niques. J Laryngol Otol. 2007;121(2):110 -113. ranted, but is unfamiliar with or concerned 10. Russell JD, Donnelly M, McShane DP, Alun-Jones T, about performing the procedure. Walsh M. What causes acute otitis externa? J Laryngol Otol. 1993;107(10):898-901. Data Sources: We performed multiple searches of PubMed 11. Kim JK, Cho JH. Change of external auditory canal Clinical Queries using the search term otitis externa. pH in acute otitis externa. Ann Otol Rhinol Laryngol. We also searched Essential Evidence Plus, the Cochrane 2009;118 (11):769 -772. Database of Systematic Reviews, the National Guideline Clearinghouse, Clinical Evidence, Dynamed, and UpToDate. 12. van Asperen IA, de Rover CM, Schijven JF, et al. Risk of otitis externa after swimming in recreational fresh Search dates: January 1, 2011, through April 6, 2011. water lakes containing Pseudomonas aeruginosa. BMJ. Figures 1 through 4 provided by Armando Lenis, MD, FACS. 1995;311(7017):1407-1410. 13. Halpern MT, Palmer CS, Seidlin M. Treatment patterns The Authors for otitis externa. J Am Board Fam Pract. 1999;12(1):1-7. 14. Rosenfeld RM, Singer M, Wasserman JM, Stinnett SS. PAUL SCHAEFER, MD, PhD, is an assistant professor, clerk- Systematic review of topical antimicrobial therapy ship director, and director for medical student education for acute otitis externa. Otolaryngol Head Neck Surg. in the Department of Family Medicine at the University of 2006;134(4 suppl):S24-S48. Toledo (Ohio) College of Medicine. 15. Kaushik V, Malik T, Saeed SR. Interventions for acute otitis externa. Cochrane Database Syst Rev. 2010; REGINALD F. BAUGH, MD, is a professor and chief of oto- (1):CD004740. laryngology in the Department of Surgery at the University 16. Hajioff D, Mackeith S. Otitis externa. Clin Evid (Online). of Toledo College of Medicine. 2010. Address correspondence to Paul Schaefer, MD, PhD, 17. Smith IM, Keay DG, Buxton PK. Contact hypersensitivity University of Toledo Health Science Campus, MS 1179, in patients with chronic otitis externa. Clin Otolaryngol 2240 Dowling Hall, 3000 Arlington Ave., Toledo, OH Allied Sci. 1990;15(2):155-158. 43614 (e-mail: [email protected]). Reprints 18. Yariktas M, Yildirim M, Doner F, Baysal V, Dogru H. are not available from the authors. Allergic contact dermatitis prevalence in patients with eczematous external otitis. Asian Pac J Immunol. Author disclosure: No relevant financial affiliations to 2004;22(1):7-10. disclose. 19. Shikiar R, Halpern MT, McGann M, Palmer CS, Seidlin M. The relation of patient satisfaction with treatment of REFERENCES otitis externa to clinical outcomes: development of an instrument. Clin Ther. 1999;21(6):1091-1104. 1. Rowlands S, Devalia H, Smith C, Hubbard R, Dean A. Otitis externa in UK general practice: a survey using the 20. Drugstore.com. http://www.drugstore.com. Accessed UK General Practice Research Database. Br J Gen Pract. April 4, 2011. 2001;51(468):533-538. 21. EverydayHealth.com. Drugs A-Z on everyday health. 2. Raza SA, Denholm SW, Wong JC. An audit of the man- http://www.everydayhealth.com/drugs/. Accessed agement of acute otitis externa in an ENT casualty clinic. April 5, 2011. J Laryngol Otol. 1995;109(2):130-133. 22. Roland PS, Belcher BP, Bettis R, et al.; Cipro HC Study 3. Rubin Grandis J, Branstetter BF IV, Yu VL. The changing Group. A single topical agent is clinically equivalent to the face of malignant (necrotising) external otitis: clinical, combination of topical and oral antibiotic treatment for radiological, and anatomic correlations. Lancet Infect Dis. otitis externa. Am J Otolaryngol. 2008;29(4):255-261. 2004;4(1):34-39. 23. England RJ, Homer JJ, Jasser P, Wilde AD. Accuracy of 4. Rosenfeld RM, Brown L, Cannon CR, et al.; American patient self-medication with topical eardrops. J Laryn- Academy of Otolaryngology–Head and Neck Surgery gol Otol. 2000;114(1):24-25.

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