Acute Otitis Externa

Aka: Acute Otitis Externa, Otitis Externa, Swimmer's Ear

1. See Also
   1. Chronic Otitis Externa
2. Definition
   1. Diffuse inflammation of the External Ear canal
3. Epidemiology
   1. Five times more common in swimmers than non-swimmers
   2. Bilateral involvement in 10% of acute cases
   3. Age peaks at 7-12 years and decreases after age 50 years
4. Pathophysiology
   1. Perfect Bacterial Environment: Moist, warm canal
   2. Commonly follows swimming or bathing
      1. Water in canal washes off oils and wax
         1. Results in dry, fissuring skin
         2. More susceptible to Trauma
         3. Excoriation from cotton swabs
5. Causes
   1. Infectious Causes
      1. Bacterial Otitis Externa (most common)
         1. Staphylococcus aureus
         2. Pseudomonas aeruginosa
         3. Polymicrobial (one third of cases)
      2. Fungal Infection (Otomycosis)
         1. Causes 10% of Acute Otitis Externa cases
         2. Causes large percentage of Chronic Otitis Externa
      3. Viral Infection
         1. Herpes simplex and Herpes Zoster
            1. Ramsay Hunt Syndrome (herpetic Vesicles in ear canal)
   2. Noninfectious causes (See Chronic Otitis Externa)
      1. Allergic Otitis Externa
         1. Allergic Contact Dermatitis (e.g. secondary to otic agents, soaps)
         2. Eczematous Dermatitis (Atopic Dermatitis)
      2. Irritant Contact Dermatitis
      3. Psoriasis
      4. Seborrheic Dermatitis
      5. Acne Vulgaris
      6. Systemic Lupus Erythematosus
6. Risk factors
   1. Moist ear canal
      1. Swimming
      2. Sweating
      3. High humidity in warm environment
   2. Generalized skin conditions
      1. Eczematous Dermatitis
      2. Seborrhea
      3. Psoriasis
      4. Acne Vulgaris
   3. Ear canal obstruction
      1. Canal stenosis or exostosis
      2. Cerumen Impaction
      3. Excessive ear canal hair
      4. Ear Foreign Body
      5. Sebaceous Cyst
   4. External Ear canal Trauma
      1. Cotton swabs
      2. Matchsticks
      3. Hairpins
      4. Earplugs
      5. Hearing Aids
      6. Finger nails
      7. Ear plugs
7. Symptoms
   1. Pain (85%)
      1. Skin tightly adherent to cartilage
         1. No room for inflammation
         2. Edema compresses nerve fibers against cartilage
      2. Exacerbated by chewing and other auricle movement
   2. Pruritus (66%)
      1. Precedes pain in acute inflammation
      2. Predominant symptom in chronic disease
   3. Otorrhea
      1. Acute Bacterial Otitis Externa
         1. Scant white mucus (may be thick)
      2. Chronic Bacterial Otitis Externa
         1. Bloody discharge with granulation tissue
      3. Fungal Otitis Externa (Otomycosis)
         1. Fluffy discharge
         2. Color: white, black, gray, blue-green or yellow
   4. Conductive Hearing Loss
      1. Associated with swelling and debris in canal
   5. Systemic symptoms absent
8. Signs
   1. Otoscopy
      1. Ear canal with erythema, edema, and exudate
      2. Tympanic Membrane mobile
      3. Visualization often requires removal of Otorrhea
         1. See Ear Canal Suction
         2. Cotton-tipped swab (alternative to suction)
            1. Wisp or fluff cotton out
            2. Mops up thin watery secretions
         3. Integral part of ear toilet (see below)
   2. Pain with movement of the tragus or auricle
   3. Lymphadenopathy at upper neck or around auricle
9. Red Flags
   1. Findings suggestive of infectious spread beyond the ear canal
      1. Fever over 101
      2. Severe Otalgia
      3. Lymphadenopathy
      4. Trismus
      5. Cranial Nerve palsy (especially Facial Nerve)
   2. Patient risk factors associated with Malignant Otitis Externa
      1. Older patients with Diabetes Mellitus
      2. Immunocompromised patients
10. Differential Diagnosis
    1. Chronic Otitis Externa
    2. Acute Otitis Media with perforated Tympanic Membrane
    3. Localized Otitis Externa (Staphylococcal Folliculitis)
    4. Suppurative Perichondritis
    5. Malignant External Otitis
    6. Chronic Otitis Media complication
    7. Furunculosis
11. Management: General
    1. Ear toilet
       1. Ear Canal Suctioning for 2-3 days to remove debris
       2. Do not put anything in ear including Cotton Swabs
    2. Topical Analgesic
       1. Precautions
          1. Avoid if Tympanic Membrane perforated
          2. May decrease effectiveness of other topical medications
          3. Consider using systemic Analgesics instead (e.g. NSAIDS)
       2. Agents
          1. Auralgan
          2. Tetracaine
    3. Cotton wick to allow medication penetration
       1. Cotton
       2. Gauze
       3. Compressed hydroxycellulose (Otowick)
    4. Tympanic Membrane Perforation or unknown status
       1. Avoid most topical ear agents (limit to specifically known safe topical agents)
       2. Avoid Flushing ear
    5. Return to swimming recommendations
       1. Consider no immersion for 7 to 10 days
       2. Competitive swimmers may return in 3 days if no pain
       3. Consider wearing ear plugs
12. Management: Cause Specific
    1. See Ear Canal Instillation for topical otic medication instillation
    2. Acute Otitis Externa
       1. See Bacterial Otitis Externa (most acute cases)
       2. See Malignant Otitis Externa
       3. See Fungal Otitis Externa (only 10% of acute cases)
    3. Chronic Otitis Externa
       1. See Fungal Otitis Externa
       2. See Allergic Otitis Externa
13. Prevention
    1. To avoid getting water in ear while bathing
       1. Put vaseline coated cotton in ear to cover meatus
       2. Ear plugs
       3. Tight fitting bathing cap
       4. Special care with Shampooing
    2. After bathing or swimming
       1. Dry canal with hair dryer on lowest setting
    3. Avoid ear Trauma
       1. Avoid cotton-tipped swabs in ear
       2. Avoid scratching inside ear
    4. Instill 1-2 drops of one of following qd and prn swim
       1. Otic Acetic Acid solution (with or without Alcohol)
       2. Aluminum acetate (Burow's Solution) in Star-Otic
14. Complications
    1. Malignant Otitis Externa
    2. Chronic Otitis Externa
15. Resources
    1. Pharmacy Technician's Letter
       1. http://pharmacytechniciansletter.therapeuticresearch.com/mobile/Newsletter.aspx?nidchk=1&cs=&s=PTL&vo=1&dd=250808&dt=2&vodd=3
16. References
    1. Beers (2004) Pediatr Emerg Care 20:250-6 [PubMed]
    2. Bojrab (1996) Otolaryngol Clin North Am 29:761-82 [PubMed]
    3. Dohar (2003) Pediatr Infect Dis J 22:299-305 [PubMed]
    4. Halpern (1999) J Am Board Fam Pract 12(1):1-7 [PubMed]
    5. Mirza (1996) Postgrad Med 99:153-8 [PubMed]
    6. Osguthorpe (2006) Am Fam Physician 74:1510-6 [PubMed]
    7. Rosenfeld (2006) Otolaryngol Head Neck Surg 134 (4 suppl): S4-23 [PubMed]
    8. Sander (2001) Am Fam Physician 63:927-42 [PubMed]
    9. Schaefer (2012) Am Fam Physician 86(11): 1055-61 [PubMed]