Otitis Externa

• Otitis externa is inflammation of the skin in the external ear canal.
• Risk factors:

  • Swimming
  • Trauma - cotton buds or earplugs
  • Removal of ear wax - ear wax is protective
• Causes:

  • Bacterial
  • Fungal
  • Eczema
  • Dermatitis
• The most common bacterial causes are:

  • pseudomonas aeruginosa
  • staphylococcus aureus
• Symptoms:

  • Ear pain
  • Discharge
  • Itchiness
  • Conductive hearing loss - if ear becomes blocked
• Examination:

  • Erythema and swelling in the ear canal
  • Tenderness of the ear canal
  • Pus or discharge
  • Lymphadenopathy in the neck or around the ear
•  If it is ruptured, the discharge in the ear canal might be from otitis media rather than otitis externa.
• Mild cases can be treated with acetic acid available over the counter - antibacterial and antifungal effect
• Moderate otitis externa is treated with topical antibiotics and steroid:

  • Neomycin, dexamethasone and acetic acid (Otomize spray)
• Patients with severe or systemic symptoms may need oral antibiotics e.g. flucloxacillin
• Fungal infections can be treated with clotrimazole ear drops.
• Malignant otitis externa:

  • Infection spreads to bones surrounding the ear and skull
  • Progresses the osteomyelitis of the temporal bone and skill
  • Associated with underlying risk factors for infection e.g. diabetes and HIV
  • More severe symptoms - headache, severe pain and fever
  • Admission, IV antibiotics
  • Can lead to facial nerve damage, meningitis, intracranial thrombosis and death