Definition
A.Otitis externa is an inflammation of the external ear canal, which commonly produces pruritus, pain, and purulent discharge. It may be acute or chronic depending on the underlying pathogenesis.
Incidence
A.Otitis externa is seen in patients of all ages.
B.Both genders are equally affected.
C.Incidence is higher during summer months.
D.Patients with asthma, allergic rhinitis, atopic dermatitis, or other chronic skin disorders are more likely to experience recurrent otitis externa.
Pathogenesis
A.Acute diffuse otitis externa (swimmer’s ear): Bacteria causes 90% of cases. Pseudomonas is the most common bacterial infection (67%), followed by Staphylococcus and Streptococcus. Infection can also be fungal (Aspergillus, 90%). Bacterial or fungal invasion is usually preceded by trauma to the ear canal, aggressive cleaning of the naturally bactericidal cerumen, or frequent submersion in water (swimming).
B.Chronic otitis externa: Condition generally results from a persistent, low-grade infection and inflammation with Pseudomonas.
C.Eczematous otitis externa: Otitis externa is associated with primary coexistent skin disorder such as atopic dermatitis, seborrheic dermatitis, and psoriasis.
D.Necrotizing or malignant otitis externa: Invasive Pseudomonas infection results in skull base osteomyelitis. Cranial nerve palsies (of the VII, IX, and XII cranial nerves) and periostitis of the skull base have been associated with necrotizing otitis externa. Necrotizing or malignant otitis externa is a life-threatening condition that occurs in diabetic or immunocompromised patients. It is most commonly seen in the immunocompromised or diabetic geriatric patient.
Predisposing Factors
A.Exposure to a moist or humid environment (frequent swimming).
B.Ear trauma from scratching, foreign object, or vigorous cleaning.
C.Use of a hearing aid or ear plugs.
D.Primary skin conditions.
E.Immunocompromised, malnourished, or comorbid conditions.
Common Complaints
A.Otalgia.
B.Itching.
C.Erythematous and swollen external canal.
D.Purulent discharge.
E.Hearing loss from edema and obstruction of canal with drainage.
Other Signs and Symptoms
A.Plugged ear sensation (aural fullness).
B.Tenderness to palpation (tragus).
Subjective Data
A.Elicit onset, duration, and intensity of ear discomfort.
B.Inquire into the patient’s history of previous ear infections.
C.Determine whether the patient notes any degree of hearing loss.
D.Question the patient about recent exposure to immersion in water (swimming).
E.Determine if the patient wears hearing aids, earplugs, or other devices that may impact the ear canal.
F.Question the patient as to ear canal cleaning practices and any recent trauma to canal.
Physical Examination
A.Temperature.
B.Inspect:
1.Carefully examine the ear with otoscope because of extreme tenderness.
2.Observe the ear for erythematous and edematous external canal; look for otorrhea and debris.
3.Observe tympanic membrane, which may appear normal.
4.Inspect nose and throat.
C.Auscultation: Auscultate heart and lungs.
D.Palpate:
1.Apply gentle pressure to tragus and manipulate pinna to assess for tenderness.
2.Palpate preauricular, postauricular, and lateral cervical lymph nodes.
Diagnostic Tests
A.Examine ear canal scrapings and drainage under microscope for hyphae (if fungal infection is suspected from previous history or ineffective topical therapy).
Differential Diagnoses
A.Otitis externa.
B.acute otitis media (AOM).
C.Chronic suppurative otitis media.
D.Cholesteatoma.
E.Mastoiditis.
F.Referred pain.
Plan
A.General interventions:
1.The primary treatment goals are to reduce pain and inflammation and to treat the underlying organism.
2.In extreme cases, the patient’s ear canal may be blocked by edema or drainage, preventing passage of ear drops. Cautiously irrigate the canal and insert a cotton wick (approximately 1 inch long for adults) by gently rotating it to allow passage of drops. Consider referral for abnormal or extensive cases.
B.
See Section III: Patient Teaching Guide Otitis Externa.
1.The patient should be advised to keep water out of the ear during treatment, which typically lasts 1 week. During that time, bathing or showering is permitted with earplugs or a cotton ball coated with petroleum jelly inserted into the ear to block water passage into the ear canal.
C.Pharmaceutical therapy (oral antibiotics are indicated only if there is an associated otitis media and should not be used alone for otitis externa):
1.For early, mild cases associated with swimming in which the primary symptom is pruritus, homemade preparations of 50% isopropyl alcohol and 50% vinegar can be used as a drying agent and to create an unsatisfactory environment for Pseudomonas growth.
2.Mild infection: Topical therapy—use of acidifying agent such as Vosol or Vosol HC, which includes a glucocorticoid therapy. Instill five drops in the ear canal three to four times daily. (Vosol and Vosol HC are contraindicated with perforated eardrum; Vosol HC is contraindicated with viral otic infections.)
3.Moderate infection: Use of an acidifying agent, antibiotic and glucocorticoid therapy, Ciprofloxacin, and Cortisporin is suggested. The suspension is recommended rather than the solution if the integrity of the tympanic membrane is in question. Other alternative medications include ofloxacin (Floxin), polymyxin B, and neomycin (Cortisporin Otic), suspension or solution:
a.If fungal infection is suspected, Nystatin 100,000 units/mL or clotrimazole topical solutions may be used for candida or yeast infections.
b.Acyclovir is the treatment of choice for herpes simplex or herpes zoster.
4.Severe or resistant infections in healthy patients may require additional management with oral antibiotics and antifungals. In addition, oral antibiotics should be considered as an adjunct to topical therapy in patients who are immunocompromised, malnourished, or have comorbidities, including associated otitis media and/or cellulitis of the outer ear:
a.Ciprofloxacin for pseudomonal infections; dicloxacillin or cephalexin for staphylococcal infections.
b.Itraconazole (Sporanox) for treatment of otomycosis (fungal otitis externa).
5.Use of acetaminophen or ibuprofen should be adequate for pain control. Pain uncontrolled by these medications should be a red flag for serious infection and warrants immediate referral.
Follow-Up
A.Follow-up is based on symptom severity and patient comorbidities.
B.If wicking was required, the patient should be seen in 24 hours.
C.Recheck mild to moderate cases in 1 week.
Consultation/Referral
A.Any patient suspected of necrotizing otitis externa requires immediate referral because of potential life-threatening complications of osteomyelitis.
Individual Considerations
A.Geriatrics:
1.Ramsay Hunt syndrome, also known as herpes zoster oticus, occurs when the shingles virus breaks out near the ear, affecting cranial nerves V, IX, and X, causing painful blisters/rash near the ear and/or the external ear canal. Facial paralysis, change in taste perception, and/or hearing loss in the affected ear may occur. Symptoms may include shingles rash near the ear and/or inside the external ear canal, ear pain, change in taste, hearing loss, ringing in the ear, dizziness, and/or facial paralysis near the ear/mouth. Prompt treatment with antiviral medications is recommended to prevent permanent damage to the nerve. Hearing loss and facial paralysis is commonly temporary but may be permanent. Nerve damage may occur. Referral to an otolaryngologist for evaluation is recommended.
2.Malignant otitis externa is found mostly in the elderly and/or diabetics. Treatments include surgical removal of dead tissue, antibiotics, and hyperbaric oxygen treatment (HBOT), if the patient is determined a candidate.
3.There is an increased risk of otitis externa with diabetic geriatrics. The primary goal is to keep blood glucose controlled and to monitor ear canals frequently.
4.Elderly population are apt to clean ears more often than younger adults secondary to dry itchy skin. Frequent cleansing may alter the immune response and pH balance of the external canal predisposing the risk of otitis externa infection.