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Southern Cross Medical Library

The purpose of the Southern Cross Medical Library is to provide information of a general nature to help you better understand certain medical conditions. Always seek specific medical advice for treatment appropriate to you. This information is not intended to relate specifically to insurance or healthcare services provided by Southern Cross. For more articles go to the Medical Library index page.

Outer ear infection (swimmer's ear)

Outer ear infection, known as otitis externa, is the infection of skin in the outer ear canal. It is sometimes referred to as swimmer's ear. Symptoms can include pain, itching, muffled hearing and a feeling of blockage and ear pressure.  Treatment and prevention will normally include removing or avoiding the causes of irritation or blockages.

What is outer ear infection?

The ear is made up of three different sections: the outer ear, the middle ear, and the inner ear. These parts all work together so you can hear and process sounds. The outer and middle ear are separated by the eardrum – a very thin piece of skin that vibrates when hit by sound waves.

Ear anatomy

This page deals with outer ear infection (otitis externa), a common condition that can affect people of all ages in which the skin that lines the outer ear canal is infected. This is normally a bacterial infection, but viral or fungal infection are also possible causes.   A separate page deals with middle ear infection (otitis media).


Factors that contribute to outer ear infection include lack of ear wax, hot and humid weather, regular water exposure, and injury to the thin layer of skin in the outer ear canal often caused by use of cotton buds or hearing aids. Swimmers are particularly prone to developing outer ear infection; hence, the condition is commonly known as swimmer's ear. People with allergic conditions, such as eczema, psoriasis, hay fever, and asthma, are more likely to develop an outer ear infection. 


The most common symptoms of outer ear infection include: 

  • Itching in the ear
  • Redness and swelling inside the outer ear canal
  • Feelings of pressure or fullness in the ear
  • Muffled hearing 
  • Mild to severe earache 
  • Discharge from the ear.

Discussion your medical history and a physical examination are usually sufficient for your doctor to diagnose an outer ear infection. 


Outer ear infection is usually successfully treated by removal of any blockage or debris in the outer ear canal, use of corticosteroid and antibiotic ear drops to control inflammation and infection, and avoidance of contributing factors (bathing and swimming) until the infection has cleared.  Moisture in the ear, and irritation of the skin in the ear canal, should be avoided.

Paracetamol or ibuprofen can be taken for pain relief. More severe cases may require oral antibiotics. 


The following ear hygiene practices can help to prevent outer ear infection: 

  • Avoid inserting objects (e.g. cotton buds) into the ear canal 
  • Avoid washing the ears with soap 
  • Avoid swimming in polluted water (look for signs at beaches and lakes alerting swimmers to high bacterial levels) 
  • Empty the ear canals of water after swimming or bathing by holding the head horizontally or using a hair dryer on a low setting. 

Frequent use of earplugs can injure the ear canal, which may increase the chances of outer ear infection occurring.


Mayo Clinic (2016). Swimmer’s ear (Web Page). Rochester, NY: Mayo Foundation for Medical Education and Research. [Accessed: 24/01/18]
O’Toole, M.T. (Ed.) (2013). Otitis externa. Mosby’s Dictionary of Medicine, Nursing & Health Professions (9th ed.). St Louis, MI: Elsevier Mosby.
Waitzman, A.A. (2017). Otitis externa (Web Page). Medscape Drugs and Diseases. New York, NY: WebMD LLC. [Accessed 24/01/18]

Reviewed: January 2018

Go to our Medical Library Index Page to find information on other medical conditions.