Definition

Otitis externa, commonly known as swimmer's ear, is an outer ear infection. The outer ear encompasses the earlobe and the ear canal up to the eardrum. Residual water in the ear canal frequently induces this condition, creating a moist environment ideal for bacterial proliferation. 

Additionally, actions such as earpicking or inserting foreign objects like cotton swabs can trigger otitis externa by damaging the delicate skin lining the ear canal. Treatment typically involves the use of ear drops. Prompt intervention can prevent more severe complications and infections.

Causes

While otitis externa is predominantly caused by bacteria, it can occasionally be caused by fungi or viruses, even though it’s rare.

Natural Defenses of the Ear

The outer ear canal possesses inherent defense systems that maintain cleanliness of the outer ear and deter infections. These protective features include:

• A thin layer of wax with acidic and water-repellent properties lines the ear canal, inhibiting bacterial growth. This wax, along with dead skin cells and other debris, accumulates and forms cerumen (earwax), which moves outward due to fine hairs in the ear canal lining.
• The outer ear's structural design, including the earlobe, helps prevent foreign objects from entering the ear.

Pathogenesis of Infection

In otitis externa, the ear's natural defense systems are compromised. Contributing factors include:

• Excess moisture in the ear canal provides an ideal environment for bacterial growth.
• Exposure to contaminated water.
• Damage to the sensitive skin of the ear canal, creating small wounds that allow germ entry.

Risk factor

Several factors can heighten the risk of developing otitis externa:

• Prolonged moisture in the ear canal due to excessive sweating, humid weather, or water remaining after swimming.
• Exposure to high levels of bacteria in contaminated water.
• Cleaning the ear canal with objects like cotton swabs, safety pins, hairpins, or nails, can cause scratches or abrasions, facilitating germ entry.
• Use of ear devices, such as earbuds or hearing aids, may inflict minor skin damage.

Symptoms

Otitis externa symptoms typically begin mildly but can intensify if untreated or if the infection spreads. Based on symptom severity, the condition is categorized as mild, moderate, and severe.

Signs and symptoms of mild otitis externa

• Itching in the ear canal
• Redness in the ear canal
• Ear discomfort, exacerbated by pulling the earlobe or pressing the tragus (small protrusion at the front of the ear)
• Clear, odorless fluid discharge from the ear

Signs and symptoms of moderate otitis externa

• Increased frequency of itching
• Intensified pain
• Spreading redness of the ear
• Increased fluid discharge
• Fullness and blockage sensation in the ear due to swelling, discharge, and earwax
• Onset of hearing loss

Signs and symptoms of severe otitis externa

• Severe pain radiating to the face, neck, or head
• Complete blockage of the ear canal
• Redness or swelling of the outer ear
• Swollen lymph nodes in the neck
• Fever

Diagnosis

Doctors typically diagnose otitis externa through a combination of patient interviews, medical history reviews, and physical examinations. However, advanced-stage infections may require additional diagnostic tests.

Initial Examination

Diagnosis is based on medical interviews and physical examinations. Laboratory tests may not be needed on the first visit. Initial evaluations often include:

• Inspecting the ear canal using an otoscope with a lighted tip to identify redness, swelling, scaliness, and debris in the ear.
• Checking the eardrum for any tears.

Further Examination

Based on initial findings, symptom severity, or infection stage, further tests may be recommended:

• If the eardrum is damaged or torn, a referral to an otolaryngologist may be necessary to examine the middle ear and determine if the infection originates there, as treatment differs between external and middle ear infections.
• If the infection is unresponsive to treatment, ear fluid or wax samples may be taken and sent to a laboratory to identify the causative germs.

Management

Treatment Goals for Otitis Externa

The primary objectives in treating otitis externa are to eliminate the infection and fully heal the ear canal.

Ear Cleansing

Proper cleaning of the external ear canal is essential to ensure that ear drops effectively reach all infected areas.

Medications for Infection

Depending on the type and severity of the infection, doctors will typically prescribe various ear drops:

• Acidic solutions, to help balance the antibacterial environment in the ear.
• Steroids, to reduce inflammation.
• Antibiotics to address bacterial infections.
• Antifungal medications to treat fungal infections.

Consult a doctor about the best way to use ear drops. For optimal use of ear drops, follow these guidelines:

• Warm the ear drops by holding the bottle in your hand for a few minutes to match body temperature, reducing discomfort.
• After applying the drops, lie on your side with the infected ear facing up. Remain in this position for a few minutes to allow thorough medicine distribution in the ear canal.
• If possible, have someone else administer the ear drops to the ear.
• To widen the ear canal for better medicine application, gently pull the ear up and back.

Oral antibiotics may be prescribed if the infection worsens or does not respond to ear drops.

Pain Management

Doctors might recommend over-the-counter pain relievers such as ibuprofen, naproxen sodium, or paracetamol to alleviate ear pain. Stronger prescription pain medications may be necessary for more severe pain or infection.

To prevent further irritation and keep the ears dry during treatment:

• Avoid swimming or diving.
• Do not use earplugs, hearing aids, or earbuds while experiencing pain or discharge.
• Protect your ears from water exposure during bathing.

Complications

While otitis externa is typically not severe if treated promptly, complications can arise, particularly with delayed treatment. Some potential complications of otitis externa include:

• Temporary hearing loss, it usually resolves once the infection is treated.
• Chronic otitis externa is characterized by signs and symptoms persisting for more than three months. This condition is more likely if complicating factors include infections of rare bacterial strains, allergic reactions to antibiotic ear drops, skin conditions like dermatitis or psoriasis, or concurrent bacterial and fungal infections.
• Cellulitis or an infection of the tissue under the skin, though rare.
• Skull and ear cartilage damage, or early stage osteomyelitis. In rare cases, the infection can spread to the ear cartilage and skull bones, causing severe pain. This is more common in older adults, diabetics, or individuals with weakened immune systems.
• Widespread infection. Advanced skull base osteomyelitis can spread infection to other parts of the body, including the brain or nearby nerves, which can be life-threatening.

Prevention

Preventive measures for otitis externa include:

• Keep ears dry. After swimming or showering, tilt your head to each side to drain water from your ears. Dry the outer ear gently with a soft towel.
• Swim carefully. Choose clean swimming areas and inquire about water quality from the facility management.
• Protect the ears, use earplugs or a swimming cap to keep ears dry while swimming.
• Consult a doctor before swimming if you've recently had an ear infection or surgery.
• Avoid ear irritation. Do not insert foreign objects into the ear. Avoid scratching or trying to remove earwax with items like cotton swabs, paper clips, or hairpins, as this can push wax deeper, irritate the ear canal's skin, or cause damage.

Earwax naturally moves towards the ear canal opening due to fine hairs in the canal lining. It will be washed away during bathing. If necessary, gently wipe the outer ear with a damp cloth, avoiding hard objects. 

If earwax is excessive or blocks the ear canal, consult a doctor for safe and sterile removal. 

When to see a doctor? 

Consult a doctor for mild symptoms of otitis externa. However, if severe ear pain and fever accompany the symptoms, seek immediate medical attention in the emergency room.

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