Management of otitis externa

• Prescribe suitable eardrops e.g. containing antibiotic and anti-inflammatory: Gentisone-HC contains gentamicin and hydrocortisone appropriate for most bacteria including anaerobes such as pseudomonas.
  
  
• Oral antibiotics may occasionally be prescribed with topical treatment. Use flucloxacillin (if not penicillin allergic) unless pseudomonas is suspected when ciprofloxacin (or aminoglycoside) should be used. One review found that when oral antibiotics were prescribed empirically it was most likely to be amoxicillin/clavulanic acid which would not cover the typical bacteria found in these infections (1)
  
  
  • note that review of the evidence suggests no clinical benefit with the use of oral antibiotics plus topical anti-infective agents compared with topical anti-infective agents alone
    • PHE guidance suggests (2):
      • First line:
        • analgesia for pain relief, and apply localised heat (such as a warm flannel)
      • Second line:
        • topical acetic acid 2% 1 spray tds for 7 days or
        • topical neomycin sulphate +/- corticosteroid 3 drops tds (consider safety issues if perforated tympanic membrane) for 7 days
        • similar cure at 7 days
      • if cellulitis or disease extends outside ear canal, or systemic signs of infection, start oral flucloxacillin and refer to exclude malignant otitis externa
        • adult and not penicillin allergic
          • flucloxacillin 250mg QDS for 7 days (if severe: flucloxacillin 500mg QDS)
        • child and not penicillin allergic
          • flucloxacillin dosing as per BNF
            
            
  • it has been suggested that (3)
    • oral antibiotics are rarely indicated
      • consider seeking specialist advice if an oral antibiotic is thought to be required (3), such as for:
        • cellulitis extending beyond the external ear canal
        • when the ear canal is occluded by swelling and debris, and a wick cannot be inserted
        • diabetes or compromised immunity, and severe infection or high risk of severe infection, for example with Pseudomonas aeruginosa
      • if an oral antibiotic is to be prescribed in primary care, the options to consider are a 7-day course of:
        • flucloxacillin, or erythromycin, if the person is allergic to penicillin, or clarithromycin, if the person can not tolerate erythromycin
      • topical treatment should still be used alongside oral antibiotics (3)
        
• test urine for sugar if patient aged over 50
  
• teach patient the usual cause: removing or breaching the natural oil barrier in the meatus allowing bacteria to penetrate into the skin of the canal
  
• educate the patient re general principles of prevention:
  • not to poke the ear at all
  • to use olive oil for wax removal and minor irritation
  • not to rub ears when drying after washing/swimming
    • after bathing or swimming, all water in the ear canals should be drained out by tilting the head to the sides
    • the external ear canal should be then dried using a hair dryer on the lowest heat setting.
  • can be prevented by maintaining a dry ear and avoiding the many above mentioned precipitants
  • insertion of cotton swabs into the ear canal and any manipulation of the canal should be avoided
• if no response in one week then consider an alternative eardrop with or without oral erythromycin; if swab taken on initial visit then prescribe based on result
  • fungal infection
    • if persistent otitis externa then consider the possibility of a fungal infection and treat with topical preparation containing an antifungal, such as clotrimazole 1% ear drops (Canesten®), or flumetasone pivalate 0.02%, clioquinol 1% ear drops (Locorten-Vioform®) (4)
  • also consider referral for aural toilet
    
    
• refer for aural toilet if there is no response

Taking a swab for microscopy and culture is not necessary in patients with uncomplicated otitis externa (3)

• however, if treatment has not been effective after 14 days, taking a swab from the ear canal for culture can aid targeting antimicrobial treatment.

Reference:

1. Mughal Z et al. A Systematic Review of Antibiotic Prescription for Acute Otitis Externa. Cureus. 2021 Mar 27;13

2. Public Health England (June 2021). Managing common infections: guidance for primary care

3. Rosenfeld RM, Schwartz SR, Cannon CR, et al. Clinical practice guideline: acute otitis externa.Otolaryngol Head Neck Surg2014;150(Suppl):S1-24.doi: 10.1177/0194599813517083

4. Kaushik V, Malik T, Saeed SR. Interventions for acute otitis externa. Cochrane Database Syst Rev. 2010 Jan 20;(1):CD004740.