CSD 3423 - Topic 4 & Immunological Disorders (Topic 6)

External ear pathologies (osteomas, exostoses, skin cancer, congenital deformities, aural atresia) + Immunological/infectious ear disorders (atopic dermatitis, allergic contact dermatitis, psoriasis, NEO, perichondritis, relapsing polychondritis, herpes zoster oticus, erysipelas, radiation OE, cysts). Grounded in lecture slide text, CSD 3423 Exam 1.

External Ear Cholesteatoma - cause

Caused by interference with conveyor belt shedding of the ear canal skin

External Ear Cholesteatoma - complication

Can destroy the temporal bone by pressure necrosis; must be surgically removed

Osteoma

A solitary, unilateral, slow-growing benign bony growth of the ear canal

Osteoma - incidence

Peaks in the 4th decade of life (30s); more common in men than women

Osteoma - cause

No clear link to cold water or radiation exposure

Exostoses

Outgrowths of bone into the ear canal, usually multiple and bilateral

Exostoses - cause

Common in surfers, thought due to frequent cold water exposure (stronger evidence than for osteomas)

Exostoses - key study

Umeda and Nakajima (1989): 80% of surfers have exostoses

Exostoses - removal indications

Conductive hearing loss, interference with conveyor belt shedding, or repeated otitis externa

Actinic Keratosis

The most common pre-cancer of the skin, caused by excessive sun exposure (solar keratosis); can lead to squamous cell carcinoma

Actinic Keratosis - appearance

Scaly, crusty growth; early lesions may form then disappear

Basal Cell Carcinoma

The most common form of skin cancer, arising from the deepest skin layer; affects 2 million Americans per year

Basal Cell Carcinoma - behavior

Rarely spreads to distant organs; main cause is excessive sun exposure (also burns, scars, tattoos)

Squamous Cell Carcinoma

The second most common skin cancer (700,000 diagnoses per year in the U.S.), arising from the upper squamous layer/epidermis

Melanoma

Cancer of the melanocytes; the most serious skin cancer, with a high probability of metastasizing to lymph nodes and distant organs

Melanoma warning signs (ABCD)

Asymmetry, ragged Border, uneven Color (blue/black/grey), changing Diameter

Skin cancer - most susceptible group

Fair skin, blond or red hair, blue/green/grey eyes; men more than women

Hematoma of the pinna

Accumulation of blood under the tissue of the pinna; becomes red, round, and diffusely swollen

Sudden loss of the pinna

Can cause difficulty in sound localization, especially front-back localization; the brain can adapt over time

Congenital outer ear problems

Serve as a 'red flag' for possible inner ear abnormalities

Synotia

Pinna fused below a small mouth

Low-set ears

Lack of appropriate ear placement

Aplasia (of the pinna)

Lack of development, or complete absence, of the pinna

Microtia

Abnormally small pinnae

Macrotia

Abnormally large pinnae

Atresia

Complete blockage or severe narrowing of the external auditory canal or meatus

Stenosis

Narrowing of the external auditory canal

Congenital Aural Atresia

A condition present at birth where the external auditory canal is completely absent/closed, indicating the pinna, external ear, and/or middle ear failed to fully form

Congenital Aural Atresia - prevalence

1 in every 10,000 to 20,000 live births

Congenital Aural Atresia - laterality

Unilateral occurs 3 to 4 times more often than bilateral; the right ear is more affected than the left

Anotia

No pinna (can occur with or without congenital aural atresia)

Schuknecht Type A (meatal atresia)

Limited to the fibrocartilaginous portion of the canal; predisposed to cholesteatoma formation

Schuknecht Type B (partial atresia)

Narrowed bony and cartilaginous portions with ossicular deformities; TM is smaller and partly replaced with a bony septum

Schuknecht Type C (total atresia)

Absent bony canal, ossicular malformations, missing TM, pneumatized mastoid

Schuknecht Type D (hyponeumatic total atresia)

Same as Type C, but with poor mastoid pneumatization

Hearing loss with pinna deformity alone

No hearing loss expected unless the ear canal or middle ear is also involved

Hearing loss with atresia/stenosis

Mild to moderately severe conductive hearing loss depending on severity; speech clarity stays fairly intact because the loss is mainly a loss of energy, not detail

Best treatment for atresia-related hearing loss

Amplification (hearing aids / Bone Anchored Hearing Aids)

Patient evaluation for congenital ear anomalies

Neuro/developmental milestones, craniofacial development, degree of aural development (TM presence, atresia vs. stenosis), facial nerve function, and hearing/amplification needs

Why CT scanning can wait in these patients

Scanning can be delayed unless sensorineural hearing loss (SNHL) is present

Why surgery is delayed in congenital aural atresia

Until pneumatization of the temporal bone is complete

Typical surgical age for external/middle ear reconstruction

6 to 10 years old; recent trend toward 5-6 years for bilateral cases, due to the importance of binaural hearing

Unilateral atresia with normal hearing in the other ear

Generally needs no medical intervention

Improvement threshold that eliminates unilateral hearing handicap

Improving hearing to 25 dB

Surgical candidacy - qualifies

Normal bone conduction thresholds, good speech discrimination, no inner ear abnormalities

Surgical candidacy - disqualifies

Little or no middle ear/mastoid pneumatization on CT scan

Labyrinthine injury (surgical complication)

High-frequency sensorineural hearing loss (HFSNHL) from direct ossicle manipulation or acoustic energy from the drill

Facial nerve injury (surgical complication)

Risk from abnormal temporal bone development; temporary paresis may occur when the nerve is transposed to access the oval window

Stenosis (post-surgical complication)

Develops in up to 25% of patients; treated with secondary meatoplasty

Canal infections (post-surgical complication)

Increased incidence because normal keratin migration and protective secretions are gone

Persistent/recurrent conductive hearing loss (post-surgical)

Caused by inadequate mobilization of ossicular mass, joint discontinuity, fixed stapes, or lateralization of the graft

Atopic Dermatitis (Eczema)

A systemic disease causing pruritic, erythematous skin lesions that are small, scaly, crusty, and fluid-filled; usually presents in childhood with a family history of asthma, allergic rhinitis, or other atopic disorders

Atopic Dermatitis - secondary infection risks

Staphylococcus aureus, herpes simplex, dermatophyte fungi and yeast (from scratching)

Atopic Dermatitis - triggers

Certain foods, environmental changes, psychological/emotional stress, airborne allergens

Atopic Dermatitis - treatment

Gentle soap, moisturizers, topical steroids

Allergic Contact Dermatitis

A hypersensitive reaction of the external ear to a known allergen (soap, shampoo, earrings, hearing aids, topical medications)

Allergic Contact Dermatitis - acute phase

Erythema, edema, pruritus; small raised lesions forming fluid-filled, crusty vesicles

Allergic Contact Dermatitis - chronic phase

Skin becomes thickened from chronic rubbing/scratching

Allergic Contact Dermatitis - treatment

Avoid the allergen; may take about three weeks for lesions to fully epithelialize; cool compresses, topical corticosteroids

Psoriasis

A chronic inflammatory skin disorder, prevalence 2-5%, about 1/3 familial with autosomal dominant transmission and incomplete penetrance; no gender bias

Psoriasis - lesion appearance

Pink, pruritic, erythematous, circumscribed plaques with a silvery adherent scale

Psoriasis - treatment

Very strong topical corticosteroids, UV light

Necrotizing External Otitis (NEO)

A potentially lethal infection of the EAC and surrounding structures, typically seen in diabetics and immunocompromised patients; caused by Pseudomonas aeruginosa

NEO - symptoms

Deep-seated aural pain, chronic otorrhea, aural fullness in a poorly controlled diabetic with a history of otitis externa

NEO - treatment

IV antibiotics for at least 4 weeks with serial gallium scans, local canal debridement, pain control; hyperbaric oxygen is experimental

NEO - mortality

Essentially unchanged despite newer antibiotics (37% to 23%); higher (60%) with multiple cranial neuropathies; can recur up to 12 months after treatment

Perichondritis/Chondritis

Infection of the perichondrium/cartilage, usually resulting from trauma to the auricle (can be spontaneous in diabetics)

Perichondritis - treatment

Mild: debridement plus topical/oral antibiotic. Advanced: hospitalization plus IV antibiotics. Chronic: surgical excision of necrotic tissue

Relapsing Polychondritis

Episodic, progressive inflammation of cartilage (suspected autoimmune) affecting the external ear, larynx, trachea, bronchi, and nose

Relapsing Polychondritis - danger

Laryngeal/tracheal involvement can cause increasing respiratory obstruction

Relapsing Polychondritis - treatment

Oral corticosteroids

Herpes Zoster Oticus

Viral infection from reactivation of varicella zoster along a cranial nerve dermatome (shingles); described by J. Ramsay Hunt in 1907

Ramsay Hunt Syndrome

Herpes zoster of the pinna with otalgia and facial paralysis

Herpes Zoster Oticus - symptom timeline

Early: burning ear pain, headache, malaise, fever. Late (3-7 days): vesicles, facial paralysis

Herpes Zoster Oticus - treatment

Corneal protection, incision/drainage of blisters, oral steroid taper (10-14 days), antivirals

Erysipelas

Acute superficial cellulitis from group A, beta-hemolytic streptococci; skin is bright red with a well-demarcated, advancing margin

Radiation-Induced Otitis Externa

Otitis externa occurring after radiotherapy; limited cases treated like chronic OE, bone involvement requires surgical debridement

Sebaceous Cyst

Caused by plugged sebaceous gland ducts; occurs most often in the post-auricular crease; may block the lateral canal

Preauricular Cyst/Sinus

A congenital malformation from a problem in embryological development; may indicate inner ear problems

Dermoid Cyst

A developmental cyst that contains hair, skin, and glands

Cysts - treatment

Surgical excision if the cyst enlarges, drains, or becomes infected; fine needle aspiration after local anesthesia is an option