Otitis externa: Treatment, symptoms, advice and help
About otitis externa:
Otitis externa (swimmer’s ear) is an inflammation of the outer ear and ear canal.
Otitis externa: Incidence, age and sex
The incidence of otitis externa is 12–14 per 1000 population per year.
Signs and symptoms of otitis externa: Diagnosis
The predominant symptom is acute ear pain, often severe, accentuated by manipulation of the pinna or by pressure on the tragus. Itching often is a precursor of pain and usually is characteristic of chronic inflammation of the canal or resolving acute otitis externa. Conductive hearing loss may result from edema of the skin and tympanic membrane, serous or purulent secretions, or the canal skin thickening associated with chronic external otitis. The canal often is so tender and swollen that the entire ear canal and Tympanic Membrane cannot be adequately visualized, and complete otoscopic examination may be delayed until the acute swelling subsides.
Causes and prevention of otitis externa
Excessive wetness (swimming, bathing,), the presence of other skin conditions (previous infection, eczema or other forms of dermatitis), and trauma (digital, foreign body or cotton tip applicators) make the skin of the canal vulnerable to infection by the normal flora or exogenous bacteria. External otitis is caused most commonly by P.aeruginosa, but also by S. aureus, Enterobacter aerogenes, Proteus mirabilis, Klebsiella pneumoniae, streptococci, coagulase-negative staphylococci, diptheroids, and fungi such as Candida and Aspergillus also may be isolated. External otitis results from chronic irritation and maceration from excessive moisture in the canal. The loss of protective cerumen may play a role, but cerumen impaction with trapping of water also may cause infection. Inflammation of the ear canal due to herpes virus, varicella zoster, other skin exanthems, and eczema also may predispose to external otitis.
Prevention: Preventing external otitis may be necessary for individuals susceptible to recurrences, especially children who swim. The most effective prophylaxis is instillation of dilute alcohol or acetic acid (2%) immediately after swimming or bathing. During an acute episode of otitis externa, patients should not swim and the ears should be protected from excessive water during bathing.
Otitis external: Complications
Rarely, facial paralysis, other cranial nerve abnormalities, vertigo, and/or sensorineural hearing loss are present. If these occur, necrotizing (malignant) otitis externa is probable. This invasive infection of the temporal bone and skull base requires immediate culture, intravenous antibiotics, and imaging studies to evaluate the extent of the disease. It is seen only in association with immunocompromised or severe malnourishment. In adults it is associated with diabetes mellitus.
Otitis externa: Treatment
If canal edema is marked, the patient may need referral to a specialist for cleaning and possible wick placement. Some recommend otic corticosteroids in addition to otic antibodies. A wick can be inserted into the ear canal for 24-48 hours. The wick can be removed after 2-3 days, at which time the edema of the ear canal usually is markedly improved, and the ear canal and Tympanic Membrane are better seen. Topical antibiotic (e.g., ofloxacin, ciprofloxacin) are then continued by direct instillation. When the pain is severe, oral analgesics (e.g. ibuprofen, codeine) may be necessary for a few days. In sub-acute and chronic infections, periodic cleansing of the canal is essential. In severe, acute external otitis associated with fever and lymphadenitis, oral or parenteral antibiotics may be indicated. A fungal infection of the external auditory canal, or otomycosis, is characterized by fluffy white debris, sometimes with black spores seen; treatment includes cleaning and application of antifungal solutions such as clotrimazole or nystatin.