Otitis Externa Dr. Kripa JacobENT SpecialistATLAS Hospital

Ruwi

Anatomy and Physiology

• Consists of the auricle and EAM• Skin-lined apparatus• Approximately 2.5 cm in length• Ends at tympanic membrane• Auricle is mostly skin-lined cartilage• External auditory meatus

– Cartilage: ~40%, Bony: ~60%– S-shaped, Narrowest portion at bony-cartilage junction

Anatomy and Physiology

• EAC is related to various contiguous structures– Tympanic membrane– Mastoid– Glenoid fossa– Cranial fossa– Infra-temporal fossa

Anatomy and Physiology

• Innervation: cranial nerves V, VII, IX, X, and greater auricular nerve

• Arterial supply: superficial temporal, posterior and deep auricular branches

• Venous drainage: superficial temporal and posterior auricular veins

• Lymphatics

OTITIS EXTERNA

DEFINITION

• An acute or chronic infection of the whole or a part of the skin of the external ear canal

CAUSES OF OTITIS EXTERNA

INFECTIVE REACTIVE

Bacterial Fungal Viral

Staph. arues

Pseudomonos

Others

Aspirigillus Niger

Candida Albicans

Herpes zoster

Others

Eczematous Seborrheic

Speculum findings:• the canal may be so swollen that a view

into the ear is impossible• In swimmers, divers and surfers, chronic

water exposure can lead to the growth of bony swellings in the canal known as exostoses. These can interfere with the drainage of wax and predispose to infection.

Organisms

1. Pseudomonas species

2. Staphylococci

3. Streptococci/Gram negative rods

4. Fungi (Aspergillus/Candida species)

Acute Otitis Externa (AOE)

• “swimmer’s ear”• Pre-inflammatory stage• Acute inflammatory stage

• Mild• Moderate• Severe

Factors contributing to AOE

• High humidity• Water exposure• Maceration of canal skin• High environmental temperature• Local trauma• Perspiration• Allergy• Stress• Removal of normal skin lipids• Absence of cerumen• Alkaline pH of canal

AOE: Pre-inflammatory Stage

• Oedema of stratum corneum and plugging of apopilosebaceous unit

• Symptoms: pruritus and sense of fullness• Signs: mild edema• Starts the itch/scratch cycle

AOE: Mild to Moderate Stage

• Progressive infection• Symptoms

• Pain• Increased pruritus

• Signs• Erythema• Increasing edema• Canal debris, discharge

AOE: Severe Stage

• Severe pain, worse with ear movement

• Signs• Lumen obliteration• Purulent otorrhoea• Involvement of peri-

auricular soft tissue

AOE: Treatment

• Most common pathogens: P. aeruginosa and S. aureus, E.coli and proteus.

• Four principles• Frequent canal cleaning; swab or suction• With sever EO, placement of a wick made of

sponge or gauze provides a pathway for drops to be delivered to the EAC wall skin for 48-72 hours!

• Topical antibiotics, and if severe>> Systemic or PO-ABT

• Pain control• Instructions for prevention

AT A GLANCE. . .

• Otalgia• Tenderness on palpation or manipulation

(Tragus sign)• Ear fullness• Conductive hearing loss.• Erythema of meatus and canal• Swelling and obstruction of canal• Crusting and discharge• Odor!

Furunculosis

• Acute localized infection• Lateral 1/3 of posterosuperior canal• Obstructed apopilosebaceous unit• Pathogen: S. aureus

Furunculosis: Symptoms

• Localized pain• Pruritus• Hearing loss (if lesion occludes canal)

Furunculosis: Signs

• Edema• Erythema• Tenderness• Occasional

fluctuance

Furunculosis: Treatment

• Local heat• Analgesics• Oral anti-staphylococcal antibiotics• Incision and drainage reserved for

localized abscess• IV antibiotics for soft tissue extension

Erysipelas

• Acute superficial cellulitis

• Group A, beta hemolytic streptococci

• Skin: bright red; well-demarcated, advancing margin

• Rapid treatment with oral or IV antibiotics if insufficient response

Otomycosis

• Acute Fungal infection of EAC skin• 10% of OE caused by fungi, not bacteria• Primary or secondary• Two most common pathogens

• 80%-90% caused by Aspergillus • Candida

• Mostly in patients who have previously been treated with antibacterial or corticosteroid ear drops

OTOMYCOSIS

Otomycosis: Symptoms

• Pruritus deep within the ear• Dull pain• Hearing loss (obstructive)• Tinnitus• Symptoms are similar to bacterial otitis

externa, but otomycosis is often associated with less pain and more pruritus

Otoscopic examination : Signs

• Swollen and erythematous EAC

• Abundant fungal debris containing filamentous elements (white, gray, yellow, or black) in cheesy material

• White, or black fungal debris

Otomycosis

Otomycosis: Treatment

• Thorough cleaning and drying of canal• Topical antifungals (clotrimazole for eg.,

amphotericine B, oxytetracycline-polymyxin, and nystatin are very effective!)

• Acidifying of the EAC with drops like 2% acetic acid, 3% boric acid are also helpful in the t/t of fungal infections.

Necrotizing (malignant) External Otitis(NEO)

• Potentially lethal infection of EAC and surrounding structures

• Pseudomonas aeruginosa is the usual culprit

• Risk Factors:

- Diabetes Mellitus

- Elderly

- Immunocompromised state

- Human Immunodeficiency Virus (HIV)• Typically seen in diabetics and

immunocompromised patients

NEO: Signs & Symptoms• Similar to Otitis Externa except

• Severe, unrelenting Ear Pain and Headache• Persistent discharge• Does not respond to topical medications• Commonly associated with Diabetes Mellitus

• Granulation tissue in posterior and inferior canal• Pathognomonic for necrotizing otitis• Occurs at bone-cartilage junction

• Extra-auricular findings• Cervical Lymphadenopathy• Trismus (TMJ involvement)• Facial Nerve Palsy or paralysis • (Bell's Palsy)

• Associated with poor prognosis

NEO: Diagnosis, Prevention and Treatment:

• Prognosis; Reportedly mortality 20-53%

• Diagnosis : History, Physical Examn, Labs and Imaging:- Labs; FBC, Culture of discharge, ESR, Serum glucose,

Serum creatinine.- Radiology; CT, or MRI (ear)

• Prevention:- Avoid use of cotton swabs in ear and other canal trauma.- Use caution when irrigating ear of high risk patients.- Treat eczema of ear canal and other pruritic dermatitis

NEO: Treatment

• Intravenous antibiotics for at least 4 weeks – with serial gallium scans monthly

• Local canal debridement until healed• Pain control• Use of topical agents controversial• Hyperbaric oxygen experimental• Surgical debridement for refractory cases

NEO: Mortality

• Death 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

Perichondritis/Chondritis

• Infection of perichondrium/cartilage• Result of trauma to auricle• May be spontaneous (overt diabetes)• Usual pathogens include pseudomonas

species and mixed flora

Perichondritis: Symptoms• Pain over auricle and deep in canal• fever• Pruritus

Perichondritis: Signs• Tender auricle• Induration• Oedema• erythaema• Advanced cases

• Crusting & weeping• Involvement of soft

tissues

Perichondritis: Treatment

• Aspiration of the pus• Use antibiotics of gram-negative coverage, specifically

anti-pseudomonals.• If frank chondritis develops, incisions should be made

in the cartilage in order to provide adequate drainage.• Mild: debridement, topical & oral antibiotic• Advanced: hospitalization, IV antibiotics• Chronic: surgical intervention with excision of necrotic

tissue and skin coverage

Herpes Zoster Oticus(Ramsay Hunt Syndrome)

• J. Ramsay Hunt described in 1907• Viral infection caused by varicella zoster• Infection along one or more cranial nerve

dermatomes (shingles).- herpes zoster of the pinna with otalgia.- facial paralysis- sensorineural hearing loss- Bullus myringitis- A vesicular eruption of the concha of the

pinna and the EAC.

Symptoms

• Early: burning pain in one ear, headache, malaise and fever

• Late (3 to 7 days): vesicles, facial paralysis

Treatment• Corneal protection• Oral steroid taper

(10 to 14 days)• Antivirals (e.g. Valacyclovir)• Facial nerve decompression

(controversial)!

Bullous Myringitis

• Viral infection • Confined to tympanic membrane• Primarily involves younger children

Bullous Myringitis: Symptoms• Sudden onset of severe pain• No fever• No hearing impairment• Bloody otorrhoea (significant) if rupture

Bullous Myringitis: Signs• Inflammation limited to TM & nearby canal• Multiple reddened, inflamed blebs.• Hemorrhagic vesicles

Bullous Myringitis: Treatment

• Self-limiting• Analgesics• Topical antibiotics to prevent secondary

infection• Incision of blebs is unnecessary

Chronic Otitis Externa• Acute otitis externa occurs in 4 of every 1000 people

per year• Otitis externa is defined as chronic when the duration

of the infection exceeds 4 weeks or when more than 4 episodes occur in 1 year

• Bacterial, fungal, dermatological aetiologies

COE: Symptoms• Unrelenting pruritus• Mild discomfort• Dryness, Crusting, and flaking of canal skin

COE: Signs

• Asteatosis• Dry, flaky skin• Hypertrophied skin• Muco-purulent otorrhoea

(occasional)

COE: Treatment

• Similar to that of AOE• Topical antibiotics, frequent cleanings• Topical Steroids• Surgical intervention

• Failure of medical treatment• Goal is to enlarge and resurface the EAC

Relapsing Polychondritis

• Uncommon progressive inflammatory disorder that may affect children, but more commonly in adults.

• Episodic and progressive inflammation of cartilages• Autoimmune etiology?• External ear, larynx, trachea, bronchi, and nose may

be involved• Involvement of larynx and trachea causes

increasing respiratory obstruction

Relapsing Polychondritis

• Fever, pain• Swelling, erythaema• Arthralgia!• Tenderness of the nasal

septum may progress to complete destruction of the septum

Diagnosis and Treatment

• Weak +ve RF• ANA +ve• High ESR,• Anaemia• And definitive Diagnosis

is made by a biopsy from the affected cartilage

- Systemic steroids such as prednisolone

- In resistant cases; dapsone, cyclophosphamide or azithioprine may be used

Radiation-Induced Otitis Externa

• OE occurring after radiotherapy

• Often difficult to treat• Limited infection treated

like COE• Involvement of bone

requires surgical debridement and skin coverage

Granular Myringitis (GM)

• De-epithelization of the TM• Localized chronic inflammation of pars

tensa with granulation tissue• Sequelae of primary acute myringitis,

previous OE, perforation of TM• Common organisms: Pseudomonas,

Proteus

GM: Symptoms• Foul smelling discharge from one ear• Often asymptomatic• Slight irritation or fullness• No hearing loss or significant pain

GM: Signs• TM obscured by pus • “peeping” granulations• No TM perforations

GM: Treatment

• Careful and frequent debridement• Topical anti-pseudomonal antibiotics• Occasionally combined with steroids• At least 2 weeks of therapy• May warrant careful destruction of granulation tissue if

no response

Eczema

• External signs to OE

(atopic, contact and sebrrheoic) dermatitis• Usual symptom is itching.• P/E; erythaema, oedema, flaking and crusting.• Treatment:

- Local cleansing.- Usage of corticosteroid and drying agents.• Metal sensitivity is the most common form of

chronic dermatitis involving the ear.!• Nickel is the most common offending metal.• Women are affected more than men.

- Ear piercing is an important cause of primary sensitization to nickel.

Conclusions

• Careful History

• Thorough physical exam

• Understanding of various disease

processes common to this area

• Vigilant treatment and patience

THANKS