Infective Otitis Externa

What is Otitis externa?

Swimmer's ear is an infection of the outer ear (the visible part of the ear, including the earlobe), ear canal or both. Also known as otitis externa, it is usually the result of excessive moisture in the ear canal, although objects placed in the ear (including cotton-tipped swabs) can also trigger the infection. Occasionally, external otitis is caused by a dermatitis such as seborrhea, eczema, or psoriasis. Anybody can be infected with external ear infection. However, it most often affects children and young adults.

Normally, water that gets into a person's ear does not pose a health risk. The inside of the ear canal is made up of delicate skin protected by a thin layer of earwax. The ear canal lining has acidic properties that protect against infection by bacteria and fungi, which are more likely to grow in dark, warm and moist environments (such as the ear canal).

Excess moisture can alter the balance of acid in the ear canal, allowing bacteria or fungi to multiply, leading to infection. In addition, the ear canal is easily traumatized. An injury to the lining of the canal may allow bacteria or fungi to penetrate the skin and create an infection. The canal is most often injured due to forceful cleaning using cotton-tipped swabs. The presence of foreign objects in the ear canal or physical trauma to the ear can also cause injury that can lead to swimmer's ear. People who scratch their ears often due to eczema, allergies or other conditions are more likely to break the skin, allowing infectious agents to penetrate more easily.

Bacteria called Pseudomonas aeruginosa are the most common cause of external otitis. These germs are found in soil and water. Other types of bacteria can also cause swimmer's ear. In rare cases, a fungal infection may be responsible for the condition.

In some cases, complications associated with swimmer's ear may arise. Some people may experience reduced hearing that lasts until the infection clears. Others may be prone to recurrent episodes of swimmer's ear (chronic otitis externa). This can lead to infection of the surrounding skin (cellulitis).

People with certain underlying illnesses (e.g., diabetes, weakened immune system) may be more susceptible to serious complications as a result of ear infections. Bone and cartilage damage, known as malignant otitis externa, occurs when infection spreads to the bone and cartilage at the base of the skull. This is an extremely painful condition that is most likely to affect older adults and people with diabetes. It may require that a patient be hospitalized in order to be properly treated. Despite its name, cancer is not a feature of malignant otitis externa. In some cases, malignant otitis externa may spread to other parts of the body, including the brain and cranial nerves.

Swimmer's ear is not is not the same thing as a middle ear infection (otitis media). An easy way to distinguish the two conditions is to gently wiggle the outer ear. If no pain or discomfort results, the condition is likely not swimmer's ear. However, swimmer's ear is sometimes associated with a middle ear infection if the eardrum ruptures.

How is External Ear Infection diagnosed and treated?

Patients who suspect that they (or a family member) have swimmer's ear should contact their physician. A physician will perform a thorough physical examination of the ear and compile a thorough medical history to diagnose swimmer's ear. A lighted instrument (otoscope) will be used to examine the ear canal and eardrum. The physician will also look for signs of infection, such as scaly or flaking skin, a cut in the skin or moisture trapped in the ear canal. If there is drainage from the ear canal, a sample of it may be examined under a microscope for the presence of bacteria or fungi.

In many cases, prescription medications are required to treat swimmer's ear. These include antibiotics and antifungal medications that are usually taken in ear drop form. Oral medications (e.g., antibiotics in pill form) are not often necessary, unless the infection has spread outside the ear canal.

Over-the-counter (OTC) ear drops do not effectively treat swimmer's ear, although they may help prevent it. It is important that patients consult their physician prior to using any type of medication (including OTC ear drops). If an ear drum contains even a small perforation, use of these products or flushing of the ear canal may cause additional problems (e.g., tinnitus, vertigo, hearing loss). Some of these complications may require surgery.

In addition, corticosteroids may be recommended to relieve itching and inflammation. Oral pain medications may also be prescribed. Most often, swimmer's ear clears up within a week of beginning treatment.

Prior to use of medications, any drainage, debris or flaky skin is usually cleared from the patient's outer ear and ear canal. This allows the medications to more effectively penetrate the area. A physician may clean the area using a suction device or a cotton-tipped probe. If the ear canal is swollen, a special wick may be placed inside it to help medication reach deeply into the ear canal.

While recovering from swimmer's ear, patients will be asked to refrain from swimming, flying or scuba diving. In addition, they may be asked to alter their bathing habits to ensure that they do not trap water in their ears.

Patients may relieve discomfort by placing a warm (not hot) heating pad against the ear. OTC pain or anti-inflammatory medications may be used, although patients should consult their physician before taking these drugs.

Patients are urged to contact their physician if they develop new symptoms after treatment has begun. Such symptoms include fever, redness of the skin behind the ear, increased pain and increased drainage. In severe or recurrent cases of swimmer's ear, a physician may refer the patient to an ear, nose and throat specialist (otolaryngologist).

Medications

• You may use non-prescription drugs, such as acetaminophen or aspirin, for minor pain.
• Ear drops that contain antibiotics and cortisone drugs to control inflammation and fight infection.
• Topical creams or ointments for fungal or bacterial infections.
• Oral antibiotics for severe infection.

Information

Brand

Generic

Label

Cipro

Ciprofloxacin

Gyne-lotrimin

Clotrimazole

Prevention methods for swimmer's ear

Although swimmer's ear cannot always be prevented, people can take several steps to reduce their likelihood of contracting this infection. Drying the ears after swimming or bathing is crucial to reducing the risk of external otitis. Some experts have recommended using a hair dryer to dry the ear canal. It may also help to use an alcohol-based ear product that will dry out the ear. Such products can be found in pharmacies. Patients should consult their physician about whether these products are right for them, and whether a homemade solution may be used.

Swimming in pools and hot tubs with good chlorine and pH control can also significantly reduce the risk of contracting swimmer's ear. It is also important not to swim in an area that has been closed due to pollution. Using earplugs during swimming can help prevent water from getting in the ear canal. Using oil or lanolin eardrops in the ears prior to swimming can also protect against the effects of water.

People are urged to take steps to prevent irritating substances from entering the ear canal. For example, it may be helpful to place cotton balls in the ears when applying sprays or dyes to the hair. Patients may also be advised to avoid frequent washing of the ear canal with soap, which can upset the acid balance of the canal lining and promote infection.

Finally, everyone is urged to avoid putting objects in their ears, including fingers and cotton-tipped swabs. This will reduce the odds of scratching the ear canal, which can lead to an ear infection.

What might complicate it?

The condition may recur a number of times over a period of months, especially if it is caused by a fungus. Severe chronic otitis externa may reflect underlying diabetes, underactive thyroid, or kidney infection.

Predicted outcome

Appropriate treatment will provide improvement in three or four days.

Alternatives

Other common causes of drainage from the external ear canal include seborrhea, psoriasis, acute otitis media, basal cell carcinoma, neurodermatitis, furunculosis, and a foreign body (in the ear).

Appropriate specialists

Dermatologist, infectious disease specialist, and otolaryngologist.

Last updated 21 November 2019