Otitis externa

• Aka swimmers ear
• Acute inflammation external ear canal, usually following water exposure
• Risks – inflammatory skin conditions/psoriasis/eczema, water exposure, trauma due to cleaning, irritants
• Clinical
  • Ear pain
  • Pruritis
  • Hearing loss
  • Pain with manipulation tragus or auricle
  • Discharge
  • If severe can extend to cellulitis adjacent ear, regional lymphadenitis
• Try to distinguish fungal debris on otoscopy
• If diabetic / immunocompromised- increased risk fungal and necrotising otitis externa
• Bacterial most commonly Pseudomonas and Staph aureus
• Fungal – candida or aspergillus
• Differentials
  • Contact dermatitis, atopic dermatitis, seborrheic dermatitis
• Treatment
  • Analgesia
  • Dry aural toilet e.g. Rolled tissues
  • Keep ear dry up to 2 weeks after treatment – ear plus, shower caps
  • Ear drops – combo corticosteroid and antimicrobial
  • Don’t have to culture routinely
  • If severe occlusion – consider wick
  • If spread to the pinna may need oral antibiotics – do MCS in this case
• Ear drops for bacterial
  • Sofradex – dexamethasone/framycetin/gramicidin – 3 drops TDS 7 days
  • Locacorten-Vioform – flumetason/cliquinol – 3 drops BD 7 days
  • If TM perforated or unsure – need to avoid aminoglycoside
  • Use ciprofloxacin/hydrocortisone – 3 drops BD 7 days
• If suspect fungal
  • Locacorten-Vioform 3 drops BD 7 days
  • Kenacomb drops – triamcinolone/gramicidin/nysatin – 3 drops TDS 7 days
• Other management:
  • Keep ear dry
  • Soft wax earplugs should be used when showering
  • No swimming. 
• Oral antibiotics are not routinely used for simple otitis externa.
• Oral antibiotics may be required for complicated otitis externa
  • significant cellulitis
  • symptoms such as fever or cervical lymphadenopathy
• If need systemic Abx – need to cover Staph and pseduomonas
  • Flucloxacillin PLUS ciprofloxacin 750mg BD for 7-10 days
• Prevent recurrence
  • Keep ear canal dry for 2 weeks after treatment
  • 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.

Acute localised otitis externa

• Usually staph aureus in assocaition with a boil
• Use dicloxacillin or flucloxacilin for 5 days
• Furuncle in external ear
  • Ear wick
  • Topical drops taht contain steroid helps reduce inflammation
  • Oral Abx

 Necrotising otitis externa

• Aka malignant
• Consider MOE if someone treated for Otitis Externa is not improving and/or they have fever and tenderness to palpation of the mastoid.
• Risks
  • Diabetes 
  • Elderly
  • immunocompromised,HIV
• Spread of infection to the cartilage and bone of the ear canal and then to the base of the skull
• Organism
  • Pseudomonas aeruginosa
  • Fungi can also cause the disease by 5% to 20% of the general population, making it the second most common causative organism, Aspergillus fumigatus being the most common cause of fungal MOE. 
  • Other organisms, such as Proteus mirabilis, Proteus sp., Klebsiella sp., and Staphylococci, have been isolated.
• Presents
  • granulation tissue in the external auditory canal
  • tenderness and swelling of the mastoid process
  • fever
  •  cranial nerve neuropathies(facial paralysis)
• Complications from MOE include
  • Abscess
  • Meningitis
  • Encephalitis
  • skull-base osteomyelitis
• Urgent refer to ID and ENT
• Usually pseudomonas
• Management
  • Mild cases may use Ciprofloxacin 750mg po BID as ciprofloxacin has good bony penetrance.  
  • For moderate to severe cases, consider Cefepime 2GM (pediatric 50mg/kg) IV TID or Piperacillin/Tazobactam 4.5 GM (pediatric 100mg/kg) IV four times