Ear pathology Notes


Osmosis High-Yield Notes

This Osmosis High-Yield Note provides an overview of Ear pathology essentials. All Osmosis Notes are clearly laid-out and contain striking images, tables, and diagrams to help visual learners understand complex topics quickly and efficiently. Find more information about Ear pathology:

Eustachian tube dysfunction

Otitis externa

Otitis media

Tympanic membrane perforation

NOTES NOTES EAR PATHOLOGY GENERALLY, WHAT IS IT? PATHOLOGY & CAUSES ▪ Structural, functional pathology affecting different ear components ▪ Outer ear: auricle, pinna, ear canal ▫ Inflammation/infection → otitis externa ▪ Outer ear, middle ear: separated by tympanic membrane (eardrum); normally no air passage/fluids between two compartments ▫ Perforated eardrum → communication through tympanic membrane ▪ Middle ear: tiny chamber; contains functional ear bones (malleus, incus, stapes) ▫ Inflammatory middle ear disease → otitis media ▪ Eustachian tube: connects middle ear to nasopharynx ▫ Failure to open/close, remove secretions → Eustachian tube dysfunction SIGNS & SYMPTOMS ▪ Hearing loss ▪ Ear pain ▪ Ear discharge 564 OSMOSIS.ORG DIAGNOSIS DIAGNOSTIC IMAGING ▪ Otoscopy ▫ Tympanic membrane visualization OTHER DIAGNOSTICS ▪ Outer ear inspection ▪ Hearing screening tests (Weber, Rinne tests) ▫ Distinguishes between conductive, sensorineural hearing loss TREATMENT MEDICATIONS ▪ Topical otic drops/systemic agents ▪ Antihistamines/corticosteroids/ decongestants (guided by specific diagnosis) SURGERY ▪ Drain fluid accumulation/debride granulation tissue/repair defect
Chapter 73 Ear Pathology EUSTACHIAN TUBE DYSFUNCTION osms.it/eustachian-tube-dysfunction PATHOLOGY & CAUSES ▪ Any primary Eustachian tube function failure ▪ Failure to equalize/dilatory dysfunction ▫ Eustachian tube may not open → tympanic membrane stretches → pain Patulous dysfunction (chronic patency) ▪ Normal Eustachian tube is two-way valve (opens to equalize pressure, closed at rest) ▪ Persistent opening → irritant/bacteria entering middle ear Ciliary dyskinesia ▪ Tiny cilia line Eustachian tube, clear out middle ear mucus secretion ▪ Ciliary dysfunction/dyskinesia: cilia fail to clear section → stagnant secretion → complications (e.g. otitis media) CAUSES Failure to equalize/dilatory dysfunction ▪ Functional: inflammation (viral infection— e.g. common cold, allergy) → Eustachian tube swelling, secretion accumulation → Eustachian tube mechanical blockage → equalization failure ▪ Anatomical: regional mass pressure (e.g. tumour) or previous trauma scar/medical procedure Patulous dysfunction (chronic patency) ▪ Weight-loss (> 6 lbs/2.7 kg) → tissue atrophy (e.g. chronic illness) ▪ Chronic allergy/gastric-content reflux → mucosal atrophy ▪ Chronic gum-chewing → repeated musclefacilitated Eustachian tube opening ▪ Short, floppy Eustachian tubes (in children) → provide little resistance against middleear reflux during ↑ positive pressure on nasopharyngeal end of tube (e.g. crying/ nose blowing) Ciliary dyskinesia ▪ Acquired: toxins → ciliary damage, paralysis → mucociliary elevator failure ▫ Cilia can’t flick back and forth (e.g. cigarette smoke) ▪ Congenital: cystic fibrosis → very thick secretions not adequately cleared COMPLICATIONS ▪ Conductive hearing loss, otitis media, tympanic membrane perforation, cholesteatoma SIGNS & SYMPTOMS ▪ Affected ear is clogged, muffled ▪ Ear pain ▪ Autophony (hearing one’s own voice, breathing) ▫ Encountered primarily in patulous dysfunction ▪ If inner ear affected → balance problems DIAGNOSIS DIAGNOSTIC IMAGING CT scan / MRI ▪ Contrast in persistent effusion cases ▫ Neoplasm may cause Eustachian tube obstruction Nasal endoscopy ▪ Inflammation, secretion, allergic manifestation signs ▫ Eustachian tube opening quality (assessed through yawn, swallowing maneuvers) Otoscopic ear examination ▪ Normal tympanic membrane appears shiny, translucent OSMOSIS.ORG 565
▪ Examine for abnormality (e.g. retraction, effusion, perforation) ▫ Dull bluish-gray/yellowish coloration denotes effusion behind membrane; reddish coloration, engorged vessels signal inflammation ▪ Pneumatic examination ▫ Fluid-filled ear minimizes tympanic membrane excursion with insufflation OTHER DIAGNOSTICS ▪ Hearing tests for conductive hearing loss ▫ Weber test: sound lateralized to affected ear ▫ Rinne test: BC > AC TREATMENT MEDICATIONS ▪ Dilatory dysfunction ▫ Upper respiratory tract inflammation (viral infection, allergy) → short intranasal/systemic decongestant, corticosteroid course ▪ Patulous dysfunction ▫ Avoid decongestants/corticosteroids SURGERY ▪ Dilatory dysfunction ▫ Tympanostomy tubes: hollow tubes inserted into eardrum → create direct opening between middle, outer ear → allow easy pressure equilibration, accumulated debris drainage OTHER INTERVENTIONS ▪ Patulous dysfunction ▫ Hydration, nasal saline drops/irrigation OTITIS EXTERNA osms.it/otitis-externa PATHOLOGY & CAUSES ▪ AKA “swimmer’s ear” ▪ Outer ear canal irritation CAUSES ▪ Outer ear canal microbial infection (primary cause) ▫ Bacterial (90%): Pseudomonas aeruginosa, Pseudomonas vulgaris, E. coli, S. aureus ▫ Fungal: Candida albicans, Aspergillus niger ▪ Dermatological conditions ▫ Allergic contact dermatitis, psoriasis, atopic dermatitis 566 OSMOSIS.ORG RISK FACTORS ▪ Frequent swimming ▪ Mechanical cleaning/irritation (cotton swabs/scratching) ▪ Ear canal occlusion (hearing aid, headphone) ▪ Diabetes SIGNS & SYMPTOMS ▪ Acute (< six weeks) ▫ Pinna traction → aggravated pain ▫ Otorrea: sticky yellow discharge) ▫ Swelling, purulent debris → external canal obstruction → conductive hearing loss, +/- aural fullness ▫ Posterior auricular lymphadenopathy
Chapter 73 Ear Pathology ▫ Complicated otitis externa: periauricular soft tissue erythema, swelling ▪ Chronic (> three months) ▫ External ear canal pruritus; epidermis atrophy, scaling; otorrhea; normal tympanic membrane DIAGNOSIS LAB RESULTS ▪ Discharge ▫ Gram stain, culture OTHER DIAGNOSTICS ▪ Note physical outer ear change (discharge, erythema, scaling) ▪ Hearing tests for conductive hearing loss ▫ Weber test: sound lateralized to affected ear ▫ Rinne test: BC > AC TREATMENT MEDICATIONS ▪ General ▫ Burow’s solution: topical drops application (buffered aluminum sulfate, acetic acid mixture) ▪ Bacterial ▫ Antipseudomonal otic drops/topical steroid drops/combination ▫ 3% acetic acid solution → acidify ear canal (bacteriostatic acidic pH) ▫ Systemic antibiotics (lymphadenopathy/ cellulitis) ▪ Fungal ▫ Topical antifungal preparation (e.g. gentian violet, boric acid) ▪ Chronic otitis externa (pruritus without obvious infection) ▫ Corticosteroid otic drops alone OTHER INTERVENTIONS ▪ General ▫ Clean ear under magnification → irrigation, suction, dry-swabbing ▪ Fungal ▫ Debridement Figure 73.1 An individual with otitis externa of the left ear. OSMOSIS.ORG 567
OTITIS MEDIA osms.it/otitis-media PATHOLOGY & CAUSES ▪ Inflammatory middle ear diseases TYPES Acute otitis media ▪ Acute middle ear compartment infection (< three weeks) ▪ Acute infection/allergies → nasopharyngeal mucous membrane inflammation → Eustachian tube dysfunction → secretion reflux/aspiration from nasopharynx to middle ear (normally sterile) → infection Otitis media with effusion ▪ Fluid presence in middle ear, with/without infection signs ▪ Eustachian tube dysfunction → trapped fixed gas volume in middle ear → surrounding tissue slowly absorbs gas → ↓ middle-ear pressure ▫ Sufficient ↓ middle-ear pressure → surrounding tissue fluid drawn into middle ear cavity → middle-ear effusion (transudate) ▪ Most common pediatric hearing loss cause Chronic suppurative otitis media ▪ Acute otitis media complication → chronic suppurative otitis media ▪ Perforated tympanic membrane with persistent drainage (> 6–12 weeks) ▪ Acute otitis media → prolonged inflammatory response → middle ear mucosal oedema; tympanic membrane ulceration, perforation → chronic middle ear, mastoid cavity inflammation → persistent discharge from middle ear through perforated tympanic membrane ▪ Persistent infection/inflammation → granulation tissue → polyps within middleear space → inflammation, ulceration, infection, granulation tissue formation cycle → eventual surrounding bony structure destruction 568 OSMOSIS.ORG CAUSES ▪ Bacteria ▫ S. pneumoniae, H. influenzae, M. catarrhalis, group A streptococcus, S. aureus) ▪ Virus ▫ Respiratory syncytial virus, influenza, parainfluenza, adenovirus) ▫ Often viral/bacterial coinfection RISK FACTORS Smoke, air-pollution exposure Immunosuppression Pacifier use; daycare Down syndrome Recent upper-respiratory tract viral infection ▪ Craniofacial malformation (cleft lip/palate, microcephaly) ▪ Cystic fibrosis ▪ ▪ ▪ ▪ ▪ Figure 73.2 A tympanic mebrane bulging as due to the accumulation of pus in the middle ear of an individual with otitis media.
Chapter 73 Ear Pathology COMPLICATIONS ▪ Tympanic membrane perforation, mastoiditis, cholesteatoma, bacterial meningitis, dural sinus thrombosis, conductive/sensorineural hearing loss SIGNS & SYMPTOMS ▪ Acute otitis media ▫ Otalgia, fever, conductive hearing loss (triad) ▫ Children: ear pulling, crying, poor sleep, irritability ▫ Crying → small blood vessel distension on tympanic membrane → mimics otitis media redness (confounds diagnosis) ▪ Otitis media with effusion ▫ Ear fullness, conductive hearing loss +/tinnitus, no pain/fever ▪ Chronic suppurative otitis media ▫ Perforated tympanic membrane; otorrhea; hearing loss; no pain/ discomfort; fever, vertigo, pain → danger signs (possible complications) DIAGNOSIS DIAGNOSTIC IMAGING CT scan/MRI ▪ Acute otitis media ▫ Severe cases with hearing loss/high fever) ▫ Excludes more serious complications (e.g. bony destruction/meningitis) Otoscopy ▪ Acute otitis media ▫ Tympanic membrane ↓ mobility, hyperemia, bulging membrane (pus behind tympanic membrane), landmark loss (malleus handle, long process not visible) ▪ Otitis media with effusion ▫ Amber/dull grey tympanic membrane discoloration; meniscus fluid level ↑ ↓, air bubbles behind tympanic membrane; air insufflation → immobile tympanic membrane ▪ Chronic suppurative otitis media ▫ Perforated tympanic membrane; otorrhea; visible granulation tissue (medial canal/middle-ear space); middle ear mucosa (through perforation) may be edematous, polypoid, pale, erythematous OTHER DIAGNOSTICS Otitis media with effusion ▪ Hearing tests for conductive hearing loss ▫ Weber test: sound lateralized to affected ear ▫ Rinne test: BC > AC ▪ Audiological investigation ▫ Flat audiogram, tympanogram TREATMENT MEDICATIONS ▪ Acute otitis media ▫ Analgesics ▫ Systemic antibiotics if severe/persistent (> three days) ▪ Otitis media with effusion ▫ Avoid antihistamines, decongestants → secretions thicken ▪ Chronic suppurative otitis media ▫ Corticosteroid drops → ↓ granulation tissue ▫ Antibiotics (topical/drops) ▫ Granulation tissue control: granulation tissue prevents affected-site topical medication penetration SURGERY ▪ Acute otitis media ▫ Frequent recurrence: tympanostomy tubes ▪ Otitis media with effusion ▫ Severe cases: tympanostomy tubes, myringotomy (tiny eardrum incision) +/ventilating-tube insertion OSMOSIS.ORG 569
OTHER INTERVENTIONS ▪ Otitis media with effusion ▫ Watchful waiting: 90% of children clear fluid in three months without intervention ▫ Minor cases: may resolve spontaneously; manual autoinflation (manually pinch nasal passage, close back of pharynx → forceful diaphragm contraction) ▪ Chronic suppurative otitis media ▫ Mechanical/irrigative debris clearing: aural toilet (mechanical removal of mucoid exudates, desquamated epithelium, associated debris prior to medication administration); aural irrigation (50% acetic acid/sterile water ear-rinse solution) PERFORATED EARDRUM osms.it/perforated-eardrum PATHOLOGY & CAUSES ▪ Tympanic membrane communication between middle ear, external environment CAUSES ▪ Otitis media ▪ Trauma ▪ Explosive/percussive force, exceptionally loud noise ▪ Iatrogenic, sudden pressure ↑ ↓ (with blocked Eustachian tubes) COMPLICATIONS ▪ Chronic infection → permanent hearing loss SIGNS & SYMPTOMS ▫ Hearing loss ▫ Tinnitus ▫ Ear-ache (infection association) ▫ Otorrhea ▫ Nausea/vomiting 570 OSMOSIS.ORG DIAGNOSIS DIAGNOSTIC IMAGING Otoscopy ▪ Perforation visualization OTHER DIAGNOSTICS ▪ Hearing tests: conductive hearing loss ▫ Weber test: sound lateralized to affected ear ▫ Rinne test: BC > AC ▪ Audiometry: conductive hearing loss TREATMENT MEDICATIONS ▪ Avoid otic drops containing gentamicin, neomycin sulfate, tobramycin ▫ Ototoxicity → permanent hearing loss ▪ Otorrhea control ▫ Topical: fluoroquinolone otic drops ▫ Systemic: antibiotics covering respiratory flora
Chapter 73 Ear Pathology SURGERY ▪ Tympanoplasty: surgical repair OTHER INTERVENTIONS ▪ Watchful waiting ▫ Perforations may heal in weeks/months Figure 73.3 A partial perforation of the ear drum. OSMOSIS.ORG 571

Osmosis High-Yield Notes

This Osmosis High-Yield Note provides an overview of Ear pathology essentials. All Osmosis Notes are clearly laid-out and contain striking images, tables, and diagrams to help visual learners understand complex topics quickly and efficiently. Find more information about Ear pathology by visiting the associated Learn Page.