Name
OTITIS EXTERNA
DESCRIPTION
DETAIL
CAUSES 1. Acute diffuse otitis externa . Traumatized external canal (eg, from use of cotton tip swab) . Bacterial infection (90%) - pseudomonas (67% cases); staphylococcus; streptococcus; gram negative rods . Fungal infection (10%) - aspergillus (90% cases); Candida, Phycomycetes; Rhizopus; actinomyces; Penicillium 2. Chronic otitis externa . Bacterial infection - pseudomonas . Eczematous otitis externa (associated with primary skin disorder): . Eczema . Seborrhea . Psoriasis . Neurodermatitis . Contact dermatitis . Purulent otitis media . Sensitivity to topical medications . Necrotizing otitis externa . Invasive bacterial infection - pseudomonas . Associated with Immunosuppression -------------------------------------------------------------------------- DIFFERENTIAL DIAGNOSIS β’ Idiopathic ear pain β’ Hearing loss β’ Cranial nerve palsy (VII, IX-XII) with necrotizing otitis externa β’ Wisdom teeth eruption β’ Basal cell or squamous cell carcinomaOTHER TESTS : * DIRECT SMEAR OF PUS WITH GRAM STAINING * IMAGING Radiologic evaluation of deep tissues in necrotizing otitis externa with high resolution CT, MRI, gallium scan and bone scan
TYPENOTES
RISK FACTORS: Acute and chronic otitis externa--Traumatization of external canal, Swimming , Hot humid weather, Use of a hearing aid, Eczematous: Primary skin disorder, Necrotizing otitis externa in adults: Elderly, Diabetes mellitusRISK FACTORS . Acute and chronic otitis externa . Traumatization of external canal . Swimming . Hot humid weather . Use of a hearing aid . Eczematous . Primary skin disorder . Necrotizing otitis externa in adults . Elderly . Diabetes mellitus . Debilitating disease . AIDS . Necrotizing otitis externa in children (rare) . Leukopenia . Malnutrition . Diabetes mellitus . Diabetes insipidus GENERAL MEASURES β’ Thorough cleansing of external canal with suction β’ Narcotic analgesics β’ Antipruritic and antihistamines (eczematous form) β’ Ear wick (Pope) for nearly occluded ear canal SURGICAL MEASURES For necrotizing otitis externa or furuncle DRUG(S) OF CHOICE . Acute bacterial and chronic otitis externa . Topical therapy for approximately 5-7 days - 2% acetic acid (VoSol HC) fi ll ear canal qid OR - Neomycin-polymyxin B-hydrocortisone (Cortisporin); if the tympanic membrane is ruptured use the suspension, otherwise the solution can be used . Ciprofloxacin-hydrocortisone (Cipro HC Otic) 0.3% suspension 3-4 drops bid . Ofloxacin (Floxin Otic) 0.3% solution 3-4 drops bid . Oral antibiotics are only indicated if there is associated otitis media or cellulitis of the outer ear . Analgesics: acetaminophen-hydrocodone (Vicodin) . Fungal otitis externa . Topical therapy anti-yeast for Candida or yeast - 2% acetic acid 3-4 drops qid - Clotrimazole 1% solution - Itraconazole oral . Parenteral antifungal therapy - amphotericin B . Patients with Ramsay Hunt syndrome: acyclovir IV . Eczematous otitis externa - topical therapy . Acetic acid 2% in aluminum acetate . 5% aluminum acetate (Burows solution) . Steroid cream, lotion, ointment (e.g., triamcinolone 0.1% solution) . Antibacterial, if superinfected . Necrotizing otitis externa . Parenteral antibiotics - antistaphylococcus and antipseudomonal . 4-6 weeks of therapy . Quinolones orally for 2-4 weeks ALTERNATIVE DRUGS Azole antifungals for fungal otitis externa PATIENT MONITORING . Acute otitis externa . 48 hours after therapy instituted to assess improvement . At the end of treatment . Chronic otitis externa . Every 2-3 weeks for repeated cleansing of canal . May require alterations in topical medication, including antibiotics and steroids . Necrotizing otitis externa . Daily monitoring in hospital for extension of infection . Baseline auditory and vestibular testing at beginning and end of therapy PREVENTION/AVOIDANCE . Avoid prolonged exposure to moisture . Utilize preventive antiseptics . Acidifying solutions with 2% acetic acid diluted 50/50 with water or isopropyl alcohol or 2% acetic acid with aluminum acetate (less irritating) after swimming . Treat predisposing skin conditions . Eliminate self-infl icted trauma to canal . Diagnose and treat underlying systemic conditions . Ear plugs . Avoid trauma with swabs, etc. POSSIBLE COMPLICATIONS . Mainly a problem with necrotizing otitis externa. May spread to infect contiguous bone and CNS structures. . Acute otitis externa may spread to pinna causing a chondritis EXPECTED COURSE/PROGNOSIS . Acute otitis externa - rapid response to therapy with total resolution . Chronic otitis externa - with repeated cleansing and antibiotic therapy the majority of cases will resolve. Occasionally, surgical intervention is required for resistant cases. . Eczematous otitis externa - resolution will occur with control of the primary skin condition . Necrotizing otitis externa - can usually be managed with debridement and antipseudomonal antibiotics. Recurrence rate is 100% when treatment is inadequate. Surgical intervention may be necessary in resistant cases or if there is cranial nerve involvement. Mortality rate is significant, probably secondary to the underlying disease.
RELATED DISEASE
Not Available Disease
DISEASE
INVESTIGATION
COMPLETE BLOOD COUNT, PUS CULTURE TEST, GRAM STAINING