1. OTITIS EXTERNADr. Mohammed Shafeeq

2. Definition It is a generalised condition of the skin in EAC characterised by general oedema & erythema which may be associated with itchy discomfort with or without ear discharge. 3. External auditory canal - Anatomy Bottom of concha to TM24mm along posterior borderDivided into: Outer/cartilaginous partInner/bony partOuter part upwards, backwards & mediallyInner part downwards,forwards & medially 4. Cartilaginous part: 8mm, outer 1/3rdFissures of SantoriniSkin is thick with ceruminous & sebaceous glandsHair is confined to this region 5. Bony part: 16mm, inner 2/3rdTympanic portion of temporal boneSkin is thin, with thin layer of sq epitheliumDevoid of hair/ceruminous glandsIsthmusAnterior recessForamen of Huschke 6. Pathogenesis Clinical course of otitis externa can be divided into: Pre-inflammatory stageAcute inflammatory stageChronic inflammatory stage 7. Pre-inflammatory stage: protective lipid/acid balance is lost stratum corneum oedematous blocks sebaceous/apocrine glands -- aural fullness/itchingdisruption of epithelial layer -- invasion of pathogens 8. A/c inflammatory stage: 3 grades mild / moderate / severe Pre-inflammatory phase > acute inflammation progressive thickening exudate, increasing oedema oblitertion of lumen, increasing painsevere stages auricular changes & cervical lymphadenopathy 9. C/c inflammatory stage: resistant inflammations lasting > 3weeks thickening of external canal skin fibrous canal stenosis 10. Pre-disposing factors Anatomical - narrow EAC (hereditary/iatrogenic/exostoses), obstruction of normal meatus (keratosis obturans/FB/hearing aids)Dermatological - eczema,seborrhoeic dermatitisAllergic long term topical medicationsPhysiological humidity, immunocompromisedTraumatic skin maceration(swimming), ear probing, laceration, radiotherapy Microbiological active COM, exposure to P.aeruginosa or fungi 11. Microbiology Pseudomonas species -- 50-65%Other Gram negative organisms 25-35%Staphylococcus aureus 15-30%Streptococci 9-15% 12. Classification (etiological basis)INFECTIVE group Bacterial Fungal OtomycosisViral Localised otitis externa (furuncle) Diffuse otitis externa Malignant otitis externaHerpes zoster oticus Otitis externa haemmorhagicaREACTIVE group Eczematous otitis externaSeborrhoeic otitis externaNeurodermatitis 13. Acute localised otitis externa Infection of a hair follicle (furuncle)begin as folliculitis-->small abscess/furuncleStaphylococcus aureusLateral cartilaginous (outer 1/3rd) portion of EAC 14. Acute localised otitis externa (contd...) Symptoms severe pain/discharge/hearing loss/aural fullnessO/E tragal tenderness/oedematous EAC/enlarged, tender preauricular LNFuruncle in posterior meatal wall --> oedema over mastoid --> obliteration of retroauricular groove 15. Acute localised otitis externa (contd...)Treatment: Early cases without abscess formation, Systemic antibioticsTopical antibiotics+corticosteroidsAnalgesics/local hot fomentation/ear pack with 10% icthammol glycerineIf abscess has formed, Incision & Drainage Topical antibiotic ointment with/without oral antibioticsRecurrent furunculosis R/o diabetes, staphylococcal skin infection, nasal vestibule harbouring staphylococci 16. Acute diffuse otitis externa Swimmer's earCommonest form of otitis externaUsual pathogens Pseudomonas aeruginosa, Staphylococcus aureus, Proteus mirabilisSymptoms pain/itching/aural fullness/hearing lossO/E tenderness/ narrow EAC with congested, oedematous skin/ clear or purulent exudates 17. Acute diffuse otitis externa (contd...) Treatment: Ear toiletMedicated wicks Acidifying/antiseptic agents gentian violetAntibiotic-steroid prepration Mild astingent 8% aluminium acetate/3% silver nitrateAntibiotics Topical antibiotics (neomycin/ciprofloxacin/ofloxacin) with/without corticosteroids Broad spectrum systemic antibioticsAnalgesics Avoid water entry/avoid usind cotton buds/avoid digital manipulation of ear canal 18. Chronic otitis externa Low grade, diffuse infection of EAC persisting for months/years Pruritis, dry hypertrophic skin of EAC leading to post inflammatory stenosis Causes are bacterial/fungal infections, also include skin conditions seborrhoeic dermatitis, psoriasis, neurodermatitis, sensitization to an topical ear drops 19. Chronic otitis externa (contd...)Treatment: GOAL prevent stenosis & restore normal skin in EAC Frequent inspection & debridment of EACAntibiotic-corticosteroid topical applicationsEAC can be painted with gentian violet/ triamcinolone/ nystatin Treat underlying causes seborrhoea, psoriasis, neurodermatitis 20. Chronic otitis externa (contd...)Surgical treatment: In case of medical treatment failure with canal stenosis Canalplasty with skin grafting restore canal patency and hearing Procedure:Abnormal skin is removed entirelyDenuded canal is enlarged using diamond burSplit thickness graft is harvested from medial surface of upper arm with a dermatome Graft placed on exposed suface 'rosebud' type of packing is done over skin graft and left for 2 weeks Crusting may occur for several weeks, requires removal till complete healing 21. Chronic otitis externa (contd...)Preventive measures: Patients instructed not to use cotton swabs or any other objects to canal Swimmers instructed to use ear plugs and advised to use alcohol-vinegar (1:1) drops after swimming 22. Malignant (necrotizing) otitis externa Progressive, lethal infection of EAC, surrounding tissue and skull baseElderly diabetic/ immunocompromised pts.Pseudomonas aeruginosa 23. Malignant otitis externa (contd...)Pathophysiology: Infection begins in EAC --> cellulitis, chondritis, osteitis, osteomyelitis May spread to osseus auditory canal & skull base through fissures of Santorini --> replacement of compact bone with granulation tissueFacial N paalysis stylomastoid foramen involvementCN IX, X, XI palsies - jugular foramen involvementJugular V thrombosis-->lateral sinus thrombosis 24. Malignant otitis externa (contd...) Symptoms: purulent discharge/excruciating pain/facial N palsy/ CN IX,X,XI palsyO/E: granulation tissue in floor of EAC at bony-cartilaginous junction is typical otoscopic findingInvestigations: C&S of discharge CT scan Gallium scan 25. Malignant otitis externa (contd...)Treatment: HospitilizationControl of diabetesAntibiotics Aminoglycosides + penicillin/cephalosporinsQuinolonesDaily debridement of EACSurgery Debridement of devitalised tissue/bone Mastoidectomy with facial N decompression / subtotal petrosectomy 26. Fungal otitis externa (Otomycosis) Fungal infection of EACAspergillus niger black headed filamented growth Aspergillus fumigatus brown Candida albicans white/creamy depositsSecondary fungal infection may be seen in pts using topical antibiotics for otitis externa/ middle ear suppuration 27. Fungal otitis externa (contd...) Symptoms: pruritis/ pain or discomfort in ear/ watery discharge with musty odour/ ear blockO/E: erythematous canal with black/grey/white fungal mass 'wet piece of filter paper' 28. Fungal otitis externa (contd...)Treatment: Ear toiletAntifungal agents nystatin/clotrimazole2% salicylic acidEar must be kept drySecondary bacterial infections antibiotic + steroid prepration Oral antifungals refractory to topical agents 29. Herpes zoster oticus HSV most frequent virus to affect EAC HSV stay dominant in sensory ganglia reactivates in decreased immunocompetence Blisters/vesicles on auricle, EAC, TM Blisters short lived, rupture, dry & heal spontaneously May develop CN VII, VIII palsy 30. Herpes zoster oticus (contd...) 'Ramsay Hunt Syndrome' clinical syndrome with facial N palsy with or without hearing loss and dizziness owing to herpes zoster Treatment: Self limiting, primarily supportive Antivirals (acyclovir) & steroids can be used 31. Otitis externa haemmorhagica Formation of haemmorhagic bullae on TM and deep meatusViral / seen in influenza epidemicsSevere ear pain / blood stain dischargeTreatment: Analgesics Antibiotics secondary infections 32. Complications Otitis Externa Cellulitis/ Perichondritis/ ChondritisMedial canal fibrosisTympanic membrane perforationMalignant otitis externa 33. Thank you