Otitis Externa

Key Features

Essentials of Diagnosis

• Rapid onset of symptoms in the past 3 weeks and

• Symptoms of ear canal inflammation, including otalgia, itching, or fullness, with or without hearing loss or jaw pain and

• Signs of ear canal inflammation, including tenderness of the tragus and/or pinna, ear canal edema and/or erythema, otorrhea, regional lymphadenitis, tympanic membrane (TM) erythema, or cellulitis of the pinna and adjacent skin

General Considerations

• Defined as a cellulitis of the soft tissues of the external auditory canal, which can extend to surrounding structures such as the pinna, tragus, and lymph nodes

• Humidity, heat, and moisture in the ear are known to contribute to the development of otitis externa, along with localized trauma to the ear canal skin

• Most common organisms are Staphylococcus aureus and Pseudomonas aeruginosa

Clinical Findings

• Acute onset of pain

• Aural fullness

• Decreased hearing

• Itching in the ear

• Manipulation of the pinna or tragus causes considerable pain

• Discharge may start out as clear then become purulent and may also cause secondary eczema of the auricle

• Ear canal is typically swollen and narrowed, and the patient may resist any attempt to insert an otoscope

• Debris is present in the canal, and it is usually very difficult to visualize the TM due to canal edema

Differential Diagnosis

• Acute otitis media with TM rupture

• Furunculosis of the ear canal

• Herpes zoster oticus

• Mastoiditis

Diagnosis

• Clinical

Treatment

• Pain control, removal of debris from the canal, topical antimicrobial therapy, and avoidance of causative factors

• Fluoroquinolone eardrops are first-line therapy

• If the ear canal is too edematous to allow entry of the eardrops, a Pope ear wick (expandable sponge) should be placed to ensure antibiotic delivery

• Oral antibiotics are indicated for any signs of invasive infection, such as fever, cellulitis of the face or auricle, or tender periauricular or cervical lymphadenopathy

• In such cases, in addition to the ototopical therapy, cultures of the ear canal discharge should be sent, and an antistaphylococcal antibiotic prescribed while awaiting culture results

Outcome

Complications

• If untreated, facial cellulitis may result

• Malignant otitis externa

  • Can develop in immunocompromised persons

  • Infection spreads to the skull base with resultant osteomyelitis

  • Life-threatening and should be evaluated with a fine-cut temporal bone CT scan

References