m.rogha m.d isfahan university of medical sciences
TRANSCRIPT
Anatomy and PhysiologyConsists of the auricle and EAMSkin-lined apparatusApproximately 2.5 cm in lengthEnds at tympanic membrane
Anatomy and PhysiologyAuricle is mostly
skin-lined cartilageExternal auditory
meatusCartilage: ~40%Bony: ~60%S-shapedNarrowest portion
at bony-cartilage junction
Anatomy and PhysiologyEAC is related to
various contiguous structuresTympanic membraneMastoidGlenoid fossaCranial fossaInfratemporal fossa
Anatomy and PhysiologyInnervation: cranial nerves V, VII, IX, X, and
greater auricular nerveArterial supply: superficial temporal,
posterior and deep auricular branchesVenous drainage: superficial temporal and
posterior auricular veinsLymphatics
Anatomy and PhysiologySquamous
epitheliumBony skin –
0.2mmCartilage skin
0.5 to 1.0 mmApopilosebaceous
unit
Perichondritis/ChondritisInfection of perichondrium/cartilageResult of trauma to auricleMay be spontaneous (overt diabetes)
Perichondritis: SignsTender auricleIndurationEdemaAdvanced cases
Crusting & weeping
Involvement of soft tissues
Perichondritis: TreatmentMild: debridement, topical & oral antibioticAdvanced: hospitalization, IV antibioticsChronic: surgical intervention with excision
of necrotic tissue and skin coverage
Relapsing PolychondritisEpisodic and progressive inflammation of
cartilagesAutoimmune etiologyExternal ear, larynx, trachea, bronchi, and
nose may be involvedInvolvement of larynx and trachea causes
increasing respiratory obstruction
Relapsing PolychondritisFever, painSwelling,
erythemaAnemia, elevated
ESRTreat with oral
corticosteroids
Herpes Zoster OticusJ. Ramsay Hunt described in 1907Viral infection caused by varicella zosterInfection along one or more cranial nerve
dermatomes (shingles)Ramsey Hunt syndrome: herpes zoster of the
pinna with otalgia and facial paralysis
Herpes Zoster Oticus: SymptomsEarly: burning
pain in one ear, headache, malaise and fever
Late (3 to 7 days): vesicles, facial paralysis
ErysipelsAcute superficial
cellulitisGroup A, beta
hemolytic streptococciSkin: bright red; well-
demarcated, advancing margin
Rapid treatment with oral or IV antibiotics if insufficient response
Radiation-Induced Otitis ExternaOE occurring
after radiotherapyOften difficult to
treatLimited infection
treated like COEInvolvement of
bone requires surgical debridement and skin coverage
Otitis ExternaBacterial infection of external auditory canalCategorized by time course
AcuteSubacuteChronic
Acute Otitis Externa (AOE)“swimmer’s ear”Preinflammatory stageAcute inflammatory stage
MildModerateSevere
AOE: Preinflammatory StageEdema of stratum corneum and plugging of
apopilosebaceous unitSymptoms: pruritus and sense of fullnessSigns: mild edemaStarts the itch/scratch cycle
AOE: Mild to Moderate StageProgressive
infectionSymptoms
PainIncreased pruritus
SignsErythemaIncreasing edemaCanal debris,
discharge
AOE: Severe StageSevere pain,
worse with ear movement
SignsLumen obliterationPurulent otorrheaInvolvement of
periauricular soft tissue
AOE: TreatmentMost common pathogens: P. aeruginosa and
S. aureusFour principles
Frequent canal cleaningTopical antibioticsPain controlInstructions for prevention
Chronic Otitis Externa (COE)Chronic inflammatory processPersistent symptoms (> 2 months)Bacterial, fungal, dermatological etiologies
COE: TreatmentSimilar to that of AOETopical antibiotics, frequent cleaningsTopical SteroidsSurgical intervention
Failure of medical treatmentGoal is to enlarge and resurface the EAC
FurunculosisAcute localized infectionLateral 1/3 of posterosuperior canalObstructed apopilosebaceous unitPathogen: S. aureus
Furunculosis: TreatmentLocal heatAnalgesicsOral anti-staphylococcal antibioticsIncision and drainage reserved for localized
abscessIV antibiotics for soft tissue extension
OtomycosisFungal infection of EAC skinPrimary or secondaryMost common organisms: Aspergillus and
Candida
Otomycosis: SymptomsOften indistinguishable from bacterial OEPruritus deep within the earDull painHearing loss (obstructive)
Granular Myringitis (GM)Localized chronic inflammation of pars tensa
with granulation tissueToynbee described in 1860Sequela of primary acute myringitis, previous
OE, perforation of TMCommon organisms: Pseudomonas, Proteus
GM: SymptomsFoul smelling discharge from one earOften asymptomaticSlight irritation or fullnessNo hearing loss or significant pain
GM: TreatmentCareful and frequent debridementTopical anti-pseudomonal antibioticsOccasionally combined with steroidsAt least 2 weeks of therapyMay warrant careful destruction of
granulation tissue if no response
Bullous MyringitisViral / mycoplasma infection Confined to tympanic membranePrimarily involves younger children
Bullous Myringitis: SymptomsSudden onset of severe painNo feverNo hearing impairmentBloody otorrhea (significant) if rupture
Bullous Myringitis: SignsInflammation
limited to TM & nearby canal
Multiple reddened, inflamed blebs
Hemorrhagic vesicles
Bullous Myringitis: TreatmentSelf-limitingAnalgesicsTopical antibiotics to prevent secondary
infectionIncision of blebs is unnecessary
Necrotizing External Otitis(NEO)Potentially lethal infection of EAC and
surrounding structuresTypically seen in diabetics and
immunocompromised patientsPseudomonas aeruginosa is the usual culprit
NEO: SymptomsPoorly controlled diabetic with h/o OEDeep-seated aural painChronic otorrheaAural fullness
NEO: SignsInflammation and
granulation Purulent
secretionsOccluded canal
and obscured TMCranial nerve
involvement
NEO: ImagingPlain filmsComputerized tomography – most usedTechnetium-99 – reveals osteomyelitis Gallium scan – useful for evaluating RxMagnetic Resonance Imaging
NEO: TreatmentIntravenous antibiotics for at least 4 weeks –
with serial gallium scans monthlyLocal canal debridement until healedPain controlUse of topical agents controversialHyperbaric oxygen experimentalSurgical debridement for refractory cases
NEO: MortalityDeath rate essentially unchanged despite
newer antibiotics (37% to 23%)Higher with multiple cranial neuropathies
(60%)Recurrence not uncommon (9% to 27%)May recur up to 12 months after treatment