Otitis externa
What antiseptics and acidifying solutions can be used for otitis externa?
Antiseptics and acidifying solutions function as bacteriostatic agents. Alcohol and acetic acid are commonly used.
What is the treatment for mild otitis externa?
For mild external otitis, we use a topical preparation combination such as acetic acid-hydrocortisone (an acidifying agent and a glucocorticoid).
What is the pathogenesis of otitis externa?
Breakdown of the skin-cerumen barrier is the first step in the pathogenesis of external otitis. Inflammation and edema of the skin then leads to pruritus and obstruction. The pruritus prompts scratching that may create further injury. This sequence of events alters the quality and amount of cerumen produced, impairs epithelial migration, and increases the pH of the ear canal. The resulting dark, warm, alkaline, moist ear canal becomes an ideal breeding ground for numerous organisms..
How is the ear canal cleaned?
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 ear drops into the site of inflammation. Ear canal cleaning should be performed through an otoscope that allows direct visualization and use of a wire loop or cotton swab to remove cerumen and debris. If the tympanic membrane is intact, the ear canal can be irrigated with a 1:1 dilution of 3% hydrogen peroxide with water at body temperature.
What are complications of otitis externa?
Complications of external otitis include periauricular cellulitis and malignant external otitis.
When should cultures be performed for otitis externa?
Cultures are generally reserved for patients with severe cases of external otitis. Performing culture is usually more costly than simply starting empiric treatment, which is usually very effective. Thus, patients with mild and moderate external otitis do not need culture of the ear canal prior to starting therapy. However, cultures should be performed in those with severe external otitis, recurrent external otitis, chronic otitis externa, immunosuppressed patients (eg, post-transplant, HIV, receiving chemotherapy or radiation therapy), infections in patients after ear surgery, and patients who do not respond to initial therapy.
What is the epidemiology of otitis externa?
External otitis can occur in all age groups. An estimated 10 percent of people develop external otitis during their lifetime. Annual rates of ambulatory care visits in the United States for external otitis are highest during childhood and decrease with age: ●7 percent ages 0 to 4 years ●19 percent ages 5 to 9 years ●16 percent ages 10 to 14 years ●9 percent ages 15 to 19 years ●5 percent ages ≥20 years External otitis is more likely to occur in the summer, compared to winter months.
What is the treatment for moderate otitis externa?
For moderate disease, we use a topical preparation combination that is acidic and contains an antibiotic and a glucocorticoid. The antibiotic should have coverage against Staphylococcus aureus and Pseudomonas aeruginosa. Cipro HC (ciprofloxacin-hydrocortisone) and Cortisporin (neomycin-polymyxin B-hydrocortisone) are good first-line agents.
What is the treatment for severe otitis externa?
For patients with severe disease, management includes topical therapy, wick placement, and, if there is evidence of deep tissue infection, oral antibiotics. We use a topical preparation that is acidic and contains an antibiotic, an antiseptic, and a glucocorticoid. The antibiotic should have coverage against S. aureus and P. aeruginosa. Cipro HC (ciprofloxacin-hydrocortisone) and Cortisporin (neomycin-polymyxin B-hydrocortisone) are good first-line agents. Patients with severe disease should also have a wick placed if swelling may prevent adequate access of topical agents to the medial canal. Wicks are commercially available and made of polyvinyl alcohol sponge. They expand as the ototopical medicine is applied. Wicks allow topical medications to reach the medial aspect of the ear canal; they also facilitate longer retention of topical solution in the affected areas. Wicks should be replaced every one to three days if significant swelling persists. For patients with deeper tissue infection (extension of infection beyond the external canal), systemic antibiotics, in addition to topical antibiotics, are indicated because of lack of adequate penetration with local therapy. When systemic antibiotics are necessary, we recommend a quinolone, such as ciprofloxacin or ofloxacin, for coverage of S. aureus and P. aeruginosa.
What is the next step for patients who do not respond to treatment?
In patients who do not respond to treatment, culture of the ear canal and/or referral to an otolaryngologist should be considered.
What is malignant otitis externa?
Malignant external otitis (also termed necrotizing external otitis) is a severe, potentially fatal complication of acute bacterial external otitis. Most common in elderly diabetic patients or other immunocompromised individuals, it occurs when the infection spreads from the skin to bone and marrow spaces of the skull base (also involving soft tissue and cartilage of the temporal region). Patients typically have severe otalgia and otorrhea with pain that appears out of proportion to examination findings. Granulation tissue at the bony cartilaginous junction of the ear canal floor is a classic finding. Edema, erythema, and frank necrosis of ear canal skin may be evident.
What physical exam findings are consistent with otitis externa?
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. However, these signs may be absent in mild cases. 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 cerumen is typically yellow, brown, white, or gray. The tympanic membrane in patients with external otitis should be mobile with pneumatic insufflation.
What differential diagnoses should be considered when evaluating a patient for otitis externa?
Otomycosis — Otomycosis is a fungal infection of the external auditory canal. Contact dermatitis — Patients with persistent edema and erythema of the ear canal and auricle despite appropriate external otitis treatment may be experiencing an allergic reaction. Chronic suppurative otitis media — Patients with chronic suppurative otitis media (CSOM) may also present with a draining ear and can be mistakenly thought to have external otitis. Carcinoma of the ear canal — Cancer of the external auditory canal is a rare disease that should always be considered any time there is an abnormal tissue growth in the ear canal or a lack of response to prolonged external otitis treatment. Psoriasis — Psoriasis can commonly involve the external ear canal, causing redness and scaling often extending to the conchal bowl and auricle.
What counseling should you provide to patients with otitis externa?
Patient education regarding proper ear hygiene cannot be overemphasized. The adage "don't put anything smaller than your elbow in your ear" to clean the ear canal is valuable advice. Patients should be told that the ear canal is self-cleaning and that fingers, towels, cotton swabs, or other foreign objects should not be inserted. The ear should be protected from water during recovery from external otitis. This can be accomplished by placing a cotton ball coated with petroleum jelly in the ear canal while bathing. Patients with active external otitis should not swim. Ideally, they should refrain from water sports for 7 to 10 days.
What is the clinical follow-up for otitis externa?
Patients will generally experience some symptom improvement within 36 to 48 hours after treatment is initiated, with full symptom resolution by about six days. The timeframe for clinical follow-up depends on the severity of external otitis. Patients with mild external otitis only need to return if symptoms persist or worsen beyond one week. For patients with moderate disease, follow-up is recommended at one to two weeks. Patients with severe disease may need to be seen even sooner.
What is periauricular cellulitis?
Periauricular cellulitis presents with erythema, edema, and warmth of the skin around the auricle. Pain is generally mild and systemic manifestations are usually absent, which help distinguish cellulitis from malignant external otitis.
What are steps patients can take to prevent otitis externa?
Specific measures for those who engage in water sports include use of ear plugs, shaking the ear dry after swimming, and blow drying the ear after water exposure (placing the blow dryer on a low setting 12 inches away from the ears). Drops containing alcohol and/or acetic acid help to dry the ear, prevent skin maceration, and re-acidify the ear canal, but it is unclear if any type of intervention prevents recurrence of external otitis. Hearing aids should be removed nightly and regularly cleaned.
What are risk factors for developing otitis externa?
Swimming or other water exposure is a well-documented risk factor for external otitis. Excess moisture leads to skin maceration and breakdown of the skin-cerumen barrier, changing the microflora of the ear canal to predominantly gram-negative bacteria Any trauma such as from excessive cleaning or aggressive scratching of the ear canal not only removes cerumen, but can also create abrasions 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. Devices that occlude the ear canal such as hearing aids, earphones, or diving caps can predispose to external otitis. 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 (eg, psoriasis, atopic dermatitis). Prior radiation therapy can cause ischemic ear canal changes, alter cerumen production and epithelial migration, and predispose to external otitis.
How is otitis externa diagnosed?
The diagnosis of external otitis is clinical, based upon a characteristic history and physical examination.
What is the anatomy of the external ear?
The external auditory canal is a cylinder measuring approximately 2.5 cm in length and 7.0 to 9.0 mm in width, extending from the conchal cartilage of the auricle to the tympanic membrane. The inner bony portion of the canal contains thin skin without subcutaneous tissue. The dermis in this area is in direct contact with the underlying periosteum. Thus, minimal inflammation or instrumentation of the bony canal causes significant pain and/or injury. The inferior tympanic recess is a small depression in the inferior medial aspect of the ear canal, adjacent to the tympanic membrane. Debris can collect in this area and cause or perpetuate infection.
What is the anatomy of the external ear (cont.)?
The fissures of Santorini are a series of embryologic fissures in the anterior aspect of the cartilaginous portion of the canal through which neurovascular tissues pass. These fissures also allow potential spread of ear canal disease to the parotid region, temporomandibular joint, and soft tissue of the upper neck.
What topical antibiotics can be used for otitis externa?
The ideal antibiotic regimen should have coverage against the most common pathogens, S. aureus and P. aeruginosa: ●The fluoroquinolones ofloxacin and ciprofloxacin provide excellent coverage against both pathogens.
What are defense mechanisms of the ear canal?
The inherent defense mechanisms of the ear canal include: ●The tragus and conchal cartilage partially cover the opening of the ear canal and help to prevent foreign body entrance. ●Hair follicles and the isthmus narrowing inhibit entry of contaminants into the ear canal. ●Cerumen helps create an acidic ear canal environment, which inhibits bacterial and fungal growth. It is also hydrophobic, repelling water that might otherwise create an ideal culture medium. In addition, the sticky quality of cerumen helps to trap fine debris.
What are the components of care for otitis externa?
The major components of managing external otitis include: cleaning the ear canal, treating inflammation and infection, and pain control.
What is the microbiology of otitis externa?
The most common pathogenic organisms responsible for external otitis are P. aeruginosa (38 percent), S. epidermidis (9 percent), and S. aureus (8 percent).
How does otitis externa present clinically?
The most common symptoms of external otitis are ear pain, pruritus, discharge, and hearing loss.
What can be used for pain control in otitis externa?
The pain from external otitis is variable. Most patients with mild to moderate levels of ear pain will have prompt relief from topical therapy. Those with pain will generally respond to oral nonsteroidal antiinflammatory agents (NSAIDs) such as ibuprofen or naproxen, which can be started at the initial visit.
What is the spectrum of severity for otitis externa?
The spectrum of external otitis ranges from mild to severe, based upon the presenting symptoms and physical examination. ●Mild disease is characterized by minor discomfort and pruritus. There is minimal canal edema. ●Moderate disease is characterized by an intermediate degree of pain and pruritus. The canal is partially occluded. ●Severe disease is characterized by intense pain, and the canal is completely occluded from edema. There is usually periauricular erythema, lymphadenopathy, and fever.
What is otitis externa?
The term external otitis (also known as otitis externa or swimmer's ear) refers to inflammation of the external auditory canal. Infectious, allergic, and dermatologic disease may all lead to external otitis. Acute bacterial infection is the most common cause of external otitis.
What topical glucocorticoids can be used for otitis externa?
Topical glucocorticoids decrease inflammation, resulting in relief of pruritus and decreased pain. Preparations used to treat external otitis include hydrocortisone, dexamethasone, and prednisolone. They are generally well-tolerated.
