The document provides an extensive overview of acute otitis externa, detailing its anatomy, causes, symptoms, diagnosis, and treatment options. Key factors that increase the risk include water exposure, trauma, and dermatologic conditions, with common symptoms being ear pain, discharge, and hearing loss. Treatment typically involves cleaning the ear canal, using appropriate antibiotics, and managing inflammation, with attention to complications like necrotizing otitis externa, which may require aggressive medical intervention.

1. Otitis Externa
DR. ADSON TUMUHIMBISE

2. Review of Anatomy of the auricle

3. Review of the Anatomy of the external ear

4. Acute otitis externa
• Inflammation of the external ear A.k.a swimmer’s ear
• Can involve the entire canal skin and mucoperiosteum (bony canal
skin) hence diffuse OE or is localised OE

6. The inherent defense mechanisms of the ear canal include:
1. The tragus and conchal cartilage partially cover the opening of the ear
canal and help to prevent foreign body entrance.
2.Hair follicles and the isthmus narrowing inhibit entry of contaminants into
the ear canal.
3. Сеrume helps create an acidic ear canal environment, which inhibits
ո
bacterial and fungal growth. It is also hydrophobic, repelling water that
might otherwise create an ideal culture medium. In addition, the sticky
quality of сеr me helps to trap fine debris.
ս ո
• NOTE; The lining of the ear canal is a keratinizing squamous epithelium
that undergoes continual sloughing. Epithelial migration is a naturally
occurring cleaning process for the ear canal that allows egress of keratin
debris and сеr mеn. Epithelial migration begins in the center of the
ս
tympanic membrane and continues out to the medial, then lateral aspects
of the ear canal.

7. Specific factors increase the risk of
external otitis
• S imming or other water exposure is a well-documented risk factor for
ԝ
external otitis. Excess moisture leads to skin maceration and
breakdown of the skin-ϲer men barrier, changing the microflora of the
ս
ear canal to predominantly gram-negative bacteria
• Any trauma such as from excessive cleaning or aggressive scratching of
the ear canal not only removes ϲer mе but can also create abrasions
ս ո
along the thin layer of skin in the ear canal, allowing organisms to gain
access to deeper tissue. In addition, part of a cotton swab may become
detached or a small piece of tissue paper may be left behind in the ear
canal; these remnants can partially disintegrate and fester, causing a
severe skin reaction and infection.

8. • Devices that occlude the ear canal such as hearing aids,
earphones, or diving caps.
• Allergic contact dermatitis can lead to external otitis (eg,
from earrings or chemicals in cosmetics or shampoos).
• Dermatologic conditions can also predispose to external
otitis (e.g., рѕοriаѕis, atopic dermatitis).
• Immunosuppression
• Prior radiation therapy can cause ischemic ear canal
changes, alter cerumen production and epithelial migration,
and predispose to external otitis.
• Swimming

10. CLINICAL FEATURES
• The most common symptoms of external otitis are ear pain, рrurit s,
ս
discharge, and hearing loss
• On physical examination, the auricle and tragus should be examined for
erythema or signs of trauma. Tenderness with tragal pressure or when the
auricle is manipulated or pulled are indicative findings of external otitis.
• Otoscopy is critical for distinguishing between external otitis, otitis media,
and other ear pathology. The ear canal usually appears edematous and
erythematous in external otitis. Debris or ϲеr mе is typically yellow, brown,
ս ո
white, or gray. Оtοmусоsis, a fungal infection of the external canal, may take
on different appearances (eg, fine, dark coating with Aspergillus; white,
sebaceous-like material with Candida). The tympanic membrane may be
erythematous in external otitis and only partially visible due to canal edema

11. DIAGNOSIS
• The diagnosis of external otitis is clinical, based upon a characteristic
history and physical examination
• The diagnosis of external otitis should also be questioned when the
patient has a perforated tympanic membrane. It is likely that the
primary focus of disease in these patients is the middle ear, with
secondary inflammation of the ear canal.
• Cultures — Cultures are generally reserved for patients with severe
cases of external otitis and recurrent otitis externa.

12. Pathophysiology of AOE
• Preinflammatory Stage
• Edematous stratus corneum layer of skin
• Fullness and itching
• Bacterial invasion
• Acute Inflammatory Stage
• Pain and tenderness
• Early stage- mild erythema and minimal edema with a small amount of
clear or slightly cloudy canal secretion
• Moderate stage- more pain, itching, edema and discharge (thicker and
more profuse)
• Severe stage- reached in the absence of treatment, characterized by
canal lumen obliteration; profuse and purulent discharge, occasional
white papules on skin, and frequent spread to adjacent tissues

15. • Medical Treatment has four fundamental principles
1.CLEANING THE EAR CANAL (aura toilet)
• Cleaning out the external canal (aural toilet) is the first step in treatment.
The removal of cerumen, desquamated skin, and purulent material from
the ear canal greatly facilitates healing and enhances penetration of topical
ear drops into the site of inflammation.
• Ear canal cleaning should be performed using an otoscope that allows for
direct visualization, employing a loop-tipped ear curette or cotton swab to
remove cerumen and debris. If the tympanic membrane (ТM) is intact, the
ear canal can be irrigated (with a 1:1 dilution of 3% hydrogen peroxide with
water at body temperature) to enhance debris removal.
• Acetic acid drops to acidify the canal

16. 2. Good use of appropriate antibiotics
• Combination topical drops (Antibiotic and steroid). Commonly
used antibiotics include fluoroquinolones like ciprofloxacin,
ofloxacin and topical aminoglycosides like tobramycin, gentamicin ;
COMBINATIONS include; ciprofloxacin-dexamethasone, polymyxin
B -neomycin-hydrocortisone. Duration of RX 7 to 14 days.
• Ear wick/ cotton stent necessary if moderate stage of swelling or
more
• Severe stages need oral antibiotics too for controlling regional
spread
• Note; A) aminoglycosides should better be used for less than 10 days to
minimize ototoxicity and should be avoided in non intact TM.
B).Proper installation of ear drops involves the patient tilting the head to
opposite shoulder, pulling the superior aspect of auricle upward.

17. 3.Treatment of inflammation and pain
• Glycerin drops for edema and pain control
• Analgesia like NSAIDS
4. Recommendations regarding prevention
• Avoid instrumentation
• Acidifying drops (vinegar/acetic acid solution) when humid
• Keep H20 out of the ear when possible
• Rarely, patients will need admission; in these cases, look for middle
ear involvement, complications, etc.; consider IV Abx in this case.
• Surgical treatment is rarely required in AOE

18. Differential Diagnosis
• Necrotizing otitis externa.
• Perichondritis, chondritis and relapsing polychondritis
• Furunculosis and carbunculosis
• Psoriasis and seborrheic dermatitis
• Carcinoma may present as infection (SCC most common, can have
BCC, melanoma, adenoma or adenoCa.)
• Contact dermatitis
• Chronic suppurative otitis media

19. • Complications
• Spread to local and regional tissues; may lead to cellulitis; Pain is
generally mild and systemic manifestations are usually absent,
which help distinguish cellulitis from malignant external otitis.
• Perchondritis, chondritis or erysipelas.
• Malignant external otitis
• Chronic otitis externa.
Rarely gets this far as most seek treatment early

20. Copyrights apply

21. Chronic Otitis Externa
• Long standing inflammation of the EAC with no complete resolution
between episodes
• No clear cut demarcation time period between AOE and COE;
differentiated using clinical findings
• Presentation:
• Chronic Inflammatory Stage
• Less pain but more profound itching, constant
• Thickened dry canal wall skin with flaking with intermittent
episodes of discharge
• Auricular eczematization , lichenification (skin thickening) and
ulceration
• Can have canal obliteration

22. • Surgical Management
• Rarely needed – used for hypertrophic COE with Tx failure to
reconstruct the ear canal
• Medical management
• Otic antibiotic and steroid combinations is mainstay
• Mild fungal infections can usually be treated with an acetic acid
solution, or topical antifungal agent, such as 1% clotrimazole.
• If the ear canal is severely swollen, an ear stent may be inserted to
facilitate the delivery of topical medications (commercial: popewick,
local: thin ribbon gauze)
• Oral Abx only following C+S. Start empirical Rx in patients with fever,
immunosuppression, diabetes, adenopathy, or an infection extending
outside the ear canal.

23. Necrotizing (Malignant) External Otitis
• Life-threatening condition that may result as a complication of AOE
• A.k.a osteomyelitis of the temporal bone
• Infection can spread via fissures of Santorini in the canal or
tympanomastoid fissure
• Almost always caused by Pseudomonas; can be fungal in HIV patients
• 25% have CN VII involvement; IX, X or XI possible
• Diagnosis. Should be suspected in a patient presenting with otorrhea
( especially at night) and otalgia that has not responded to topical
antibiotics.
• Otalgia > 1 month
• Several weeks of purulent otorrhea with granulations
• DM, immunocompromised or elderly are high risk factors
• Cranial nerve involvement

24. • Clinical/Radiographic Findings
• Usually have granulations in floor of the canal
• Bony erosion on contrast-enhanced CT
• Lab; elevated ESR/CRP
• Differential Diagnosis
• Severe AOE
• Carcinoma like SCC
• Canal cholesteatoma (keratinized collection of squamous epithelial
cells in the middle ear or mastoid that may get infected)
• Eosiniphilic granuloma or Wegener’s granulomatosis

25. • Medical Treatment: Manage like other osteomyelitis
• Dual-agent long-term IV antibiotics recommended. A prolonged course
of IV antibiotics, lasting for up to 6 weeks, may be required. Anti
pseudomonal drugs like cipro, piperacillin /tazobactum, cefepime,
ceftazidime.
• Vigorous blood-sugar control
• Frequent aural toilet and antibiotic ear drops
• Fungal NEO requires long duration of treatment (12 weeks)
• Surgical Treatment
• Surgical debridement and suction of the ear canal is usually necessary
under magnification
• Biopsy if suspicious for tumor (by ENT surgeon)

26. Other Related Conditions
• Perichondritis and Chondritis (Localised OE)
• Complication of infections or trauma
• Cartilage oozes; canal can swell shut
• Medical treatment same as above
• Surgical is different: just debride cartilage leaving skin
• Drain can be used with bacitracin irrigation via drain post-op
• Furunculosis (hair follicle infection) and Carbunculosis ( coalescence of
several inflamed follicles into a single inflammatory mass)- Localised OE
Gram +ive infections of hair follicles
• Lesions are small and circumscribed
• Rx: Warm soaks, or I&D if it doesn’t pop spontaneously; drops

27. • Otomycosis
• Fungal Infection of EAC skin; typically in setting of COE
• Aspergillus most common; very itchy
• Otoscopy shows white, black or gray membrane/ discharge
• Dry the ear; antifungal powders are helpful or acid , combination drops
• Herpes Zoster and Simplex ((Localised OE))
• Initially: burning, pain or headache; vesicles within days
• Crusts following vesicle rupture
• Zoster is unilateral in dermatome distribution
• Antivirals like acyclovir or famcyclovir may help

28. • Dermatoses
• Caused by irritant (acid, alkalis, soap, plastic hearing aid, etc.)
• Allergic = delayed hypersensitivity (rubber from headphones; nickel
from ear-rings)
• Erythema, itching, discharge and vesiculation
• Remove irritating agent – use steroids
• Seborrheic dermatitis is more widespread and refractory to treatment
• Radiation-Induced Otitis Externa
• Weakened defenses from radiation; leads to inflammation/infection.
• Manage as AOE.
• In case of osteoradionecrosis, refer to ENT

29. • Any questions?????