M.Rogha M.DIsfahan university of medical sciences

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: SymptomsPain over auricle and deep in canalPruritus

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

Herpes Zoster Oticus: TreatmentCorneal protectionOral steroid taper (10 to 14 days)Antivirals

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: SymptomsUnrelenting pruritusMild discomfortDryness of canal skin

COE: SignsAsteatosisDry, flaky skinHypertrophied

skinMucopurulent

otorrhea (occasional)

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: SymptomsLocalized painPruritusHearing loss (if lesion occludes canal)

Furunculosis: SignsEdemaErythemaTendernessOccasional

fluctuance

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)

Otomycosis: SignsCanal erythemaMild edemaWhite, gray or

black fungal debris

Otomycosis: TreatmentThorough cleaning and drying of canalTopical antifungals

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: SignsTM obscured by

pus “peeping”

granulationsNo TM

perforations

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: DiagnosisClinical findingsLaboratory evidenceImagingPhysician’s suspicion

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