OVERVIEW

What is otitis externa?

Otitis externa, also known as swimmer's ear, refers to a diffuse inflammation of the skin and subcutaneous tissue of the external ear canal caused by bacterial or fungal infections, allergens, or ear trauma.

Typical symptoms include ear pain, discharge, and itching. Acute bacterial infection is the most common cause and is not contagious. The main treatments for otitis externa include cleaning the ear canal, treating inflammation and infection, and managing pain.

If left untreated, the infection may spread to surrounding tissues, leading to cellulitis, malignant otitis externa, or even complications such as parotitis, meningitis, brain abscess, or encephalomalacia.

Is otitis externa common?

Otitis externa is common, affecting about 10% of people, with children being more susceptible.

SYMPTOMS

What are the common symptoms of otitis externa?

• Pain: Noticeable ear pain, sometimes even severe. Touching the tragus may also cause pain, and the pain worsens when opening the mouth or chewing. Occasionally, pain may radiate to the same side of the head, and there may be slight discharge from the ear canal.

• Itching: Sometimes, the external ear canal may feel itchy. There may also be foul-smelling yellow-white discharge. Occasionally, unpleasant white or yellow discharge may be expelled from the ear.

• Other symptoms: May be accompanied by fatigue, fever, tinnitus, hearing loss, or a feeling of fullness in the ear.

How does otitis externa develop?

It mainly occurs when water enters the ear canal, the skin is injured, or immunity is weakened. These conditions compromise the skin barrier function of the external ear canal, allowing bacteria to invade and cause inflammation.

What types of otitis externa are there?

Based on the patient's symptoms and the severity of inflammation observed during examination, otitis externa can be classified into:

• Mild otitis externa: Slight pain, discomfort, or itching in the ear canal. Examination may reveal mild redness and swelling of the ear canal skin.

• Moderate otitis externa: More noticeable pain or itching. Examination shows significant swelling of the ear canal skin, partially blocking the canal but not completely.

• Severe otitis externa: Intense ear pain, possibly accompanied by fever, general malaise, headache on the same side, and worsened pain when opening the mouth or chewing. Severe itching may also occur. Examination reveals swollen ear canal skin completely blocking the canal, redness around the ear, and possibly swollen, painful lymph nodes on the same side.

What complications or serious consequences can otitis externa cause?

• Spread of inflammation to surrounding tissues, leading to periauricular cellulitis.

• In diabetic patients or the elderly, bacterial infection may progress to malignant otitis externa (also called necrotizing otitis externa), a potentially life-threatening complication of acute bacterial otitis externa.

• Infection spreading to nearby areas may cause parotitis. If it reaches the base of the brain, it can lead to meningitis, brain abscess, encephalomalacia, or even death.

CAUSES

What are the common causes of otitis externa?

• Water entering the external ear canal, such as during swimming.
• Long-term irritation of the external ear canal by pus from suppurative otitis media.
• Damage to the skin of the external ear canal, such as using hard tools to remove earwax.
• Individuals with diabetes or elderly people, who have weakened local resistance in the external ear canal.
• Long-term use of hearing aids, earphones, or diving caps.
• Local allergic reactions caused by wearing earrings or ear studs.
• Irritation of the external ear canal by chemicals in cosmetics or shampoo.
• People with psoriasis or atopic dermatitis are more prone to otitis externa.
• Individuals who have undergone radiotherapy.

The above factors make it easier for various pathogens, such as bacteria or fungi, to cause infections.

Who is more likely to develop otitis externa?

It commonly occurs in children, individuals with diabetes, those with allergic constitutions, or people who wear hearing aids for extended periods.

Is otitis externa contagious?

Generally, it is not contagious.

DIAGNOSIS

How is otitis externa diagnosed?

• Obvious symptoms: Significant ear pain, possibly with a small amount of discharge from the ear canal. May be accompanied by symptoms such as fatigue and fever. Sometimes, itching in the ear canal may occur, along with tinnitus, hearing loss, or a feeling of fullness in the ear.

• History of ear infections, previous ear surgery, recent use of hearing aids, recent trauma to the ear canal by hard objects, recent use of ear instruments, or recent water exposure in the ear.

• Physical examination may reveal redness of the auricle and tragus. Pain may occur when pressing the tragus or pulling the auricle.

• Otoscopy may show redness and swelling of the ear canal, along with various types of discharge or earwax. The eardrum may also appear red.

If the above conditions are met, a diagnosis can generally be confirmed.

What tests are needed for otitis externa?

• Complete blood count (CBC): Helps diagnose bacterial infections.

• Otoscopy: Provides a clear view of the severity of inflammation in the ear canal.

• Culture of ear canal discharge: A small swab is used to collect discharge from the ear canal for testing, mainly to identify the specific bacteria or fungi causing the infection.

What diseases can otitis externa be confused with?

• Allergic contact dermatitis of the ear canal: Caused by an allergic reaction to medications, cosmetics, or shampoos applied to the ear canal, with itching as the main symptom. Patch testing can help identify the allergen.

• Chronic suppurative otitis media: Mainly presents with purulent discharge from the ear canal, along with ear pain, hearing loss, tinnitus, or dizziness. However, there is usually no pain when pulling the tragus, and obvious perforation of the eardrum may be present. An ear CT scan may help with differential diagnosis if needed.

• Ear canal cancer: Should be considered if abnormal growths are present in the ear canal or if long-term treatment for otitis externa is ineffective. Common symptoms include mild pain and bloody discharge from the ear canal. A biopsy can confirm the diagnosis.

• Psoriasis of the ear canal: Psoriasis can occur in the ear canal, causing redness and flaking. A biopsy can aid in diagnosis.

TREATMENT

Which department should I visit for otitis externa?

Otolaryngology (ENT).

What are the treatment options for otitis externa?

The main treatments for otitis externa include: cleaning the ear canal, treating inflammation and infection, and managing pain.

• Bacterial otitis externa:

  • Systemic antibiotics to control infection.
  • Symptomatic treatment with sedatives or pain relievers if needed.
  • Removal of earwax, pus, or debris under otoscopy, followed by ear canal irrigation with hydrogen peroxide.
  • Topical application of antibiotic or corticosteroid ointments/drops, such as ofloxacin ear drops.

• Fungal otitis externa:

  • Topical antifungal treatments, such as 1% clotrimazole solution or other antifungal creams/ointments applied to the ear canal.
  • Refractory cases may require oral antifungal medication.

Is follow-up necessary for otitis externa? How is it done?

Yes, follow-up is required, and the schedule depends on severity:

• Mild cases: Revisit if symptoms persist or worsen after 1 week.
• Moderate cases: Recommended follow-up in about 1 week.
• Severe cases: Revisit every 2–3 days.

Can otitis externa be completely cured?

Yes, timely treatment can fully cure otitis externa.

Can otitis externa recur after treatment? What if it recurs?

Otitis externa may recur due to reinfection. If it does, seek medical attention immediately for proper diagnosis and standardized treatment.

DIET & LIFESTYLE

What should patients with otitis externa pay attention to in their diet?

• There are no special dietary restrictions; a healthy and balanced diet is sufficient.

• When cooking, use less salt, less oil, and fewer high-salt seasonings. Avoid pickled vegetables and meats.

• Do not rely solely on refined rice and wheat for staple foods. Replace some with whole grains, legumes, potatoes, or pumpkin.

• Balance meat and vegetables. Prefer white meats like chicken, duck, and fish, and limit fatty meats. Eggs and milk are important sources of protein and other nutrients.

• Vegetarians can eat more beans and bean products to supplement protein.

• Eat plenty of fruits and vegetables.

• Avoid alcohol as much as possible.

What should patients with otitis externa pay attention to in daily life?

• During recovery, avoid getting water in the ears. When showering, place a cotton ball coated with petroleum jelly in the ear canal to prevent water entry.

• Avoid swimming while suffering from otitis externa.

• Do not wear hearing aids or headphones during otitis externa.

• Avoid picking the ears.

PREVENTION

Can otitis externa be prevented? How to prevent it?

Otitis externa can be prevented. Specific measures are as follows:

• Avoid using hard objects to clean the ears, such as fingers, towels, cotton swabs, or other hard items.
• For frequent swimmers, shake out or use a hairdryer to dry the ears after water enters the ear canal, and avoid using cotton swabs.
• Those engaged in water sports should wear earplugs.
• Avoid wearing hearing aids or headphones for extended periods. Hearing aids should be removed at night and cleaned regularly.
• Diabetic patients should actively control blood sugar levels.
• Individuals with suppurative otitis media should seek timely treatment and keep the ear canal clean.
• Prevent shampoo, conditioner, cosmetics, etc., from entering the ear canal.