Outer ear infection (otitis externa)

The medical term for an outer ear infection is otitis externa. This means inflammation of your outer ear canal (the tube that leads into your ear). It’s often caused by an infection.

About outer ear infection

An outer ear infection can be acute or chronic. When describing an illness, the terms 'acute' and 'chronic' refer to how long you have had it, not to how serious the condition is. An acute outer ear infection comes on suddenly and usually goes away within a week of receiving treatment. Chronic outer ear infection causes ongoing symptoms that may last for several months or keep reoccurring.

Cleaning your ears with cotton buds can cause an outer ear infection. This can cause damage to your ear canal and irritate it, and removing too much wax or pushing wax into your ear can increase your risk of inflammation and infection.

Sometimes, a hair follicle at the entrance to your ear canal becomes infected, causing a boil. This is called localised otitis externa.

If an infection affects more of your ear canal and reaches your ear drum, this is called widespread or diffuse otitis externa. This type of outer ear infection is sometimes called swimmer's ear because it often develops after you have spent time in water.

Symptoms of outer ear infection

Symptoms of an outer ear infection can include:

• pain
• itching
• discharge from your ear
• temporarily dulled hearing – if the swelling is enough to block your ear canal

If you have any of these symptoms, see your GP.

Complications of outer ear infection

Infections can spread across your skin (cellulitis) or form a large abscess.

Otitis externa can sometimes progress to a severe infection called malignant otitis. This is when the infection spreads into the bones surrounding your ear, which make up your skull. It can be life-threatening without treatment. If you have problems with your immune system or diabetes, you may be more likely to get malignant otitis.

If left untreated, an outer ear infection can cause deafness. This is because your ear canal can become narrowed or completely blocked.

Causes of outer ear infection

Outer ear infections are usually caused by bacteria or yeast (fungal infection). Anything that irritates the skin of your ear canal or causes an allergic reaction can also cause inflammation.

You’re more likely to develop an outer ear infection if you:

• damage your ear canal – with a cotton bud, your fingernail, or any other object
• use hearing aids or earplugs – these can irritate your ear canal or introduce bacteria
• swim often – this can affect the amount of ear wax in your ear; too little allows bacteria to grow and too much causes water to become trapped, becoming an ideal environment for bacteria
• swim in contaminated water – this may introduce bacteria
• live in a hot, humid climate – the infection is then known as tropical ear
• are sensitive to certain soaps, shampoos, hairsprays and hair dyes – these can irritate your ear canal
• have a build-up of wax in your ear canal that causes discomfort and signs of infection
• have a narrow ear canal, which means that water can become trapped and is susceptible to bacteria
• have a skin condition, such as dermatitis or psoriasis – broken skin is more likely to become inflamed

Diagnosis of outer ear infection

Your GP will ask about your symptoms and examine you. He or she may also ask you about your medical history.

Your GP may look into your ear using an instrument called an otoscope to check for signs of swelling and infection. He or she may ask you to move your jaw to see if you feel pain.

If your symptoms don't improve after treatment or they reoccur, your GP may take a sample of the discharge from your ear using a swab. This will be sent to a laboratory for testing to find out whether your ear infection is caused by a bacterial or fungal infection.

If you have reoccurring outer ear infections that don’t respond to treatment, or you have suspected malignant otitis, your GP will refer you to an ear, nose and throat (ENT) specialist – a doctor specialising in conditions affecting the ear.

Treatment of outer ear infection

Treatment usually consists of controlling pain and treating the inflammation.

Medicines

The following medicines can help relieve and treat the symptoms of an outer ear infection.

• Over-the-counter painkillers (eg paracetamol or ibuprofen) to relieve pain.
• Acetic acid ear drops or spray to kill several types of bacteria. You can buy these over-the-counter. They are often used to treat mild infections.
• Antibiotics to treat a bacterial or yeast infection. These are usually prescribed as ear drops but your GP may prescribe tablets if you have widespread infection or you’re at risk of having a severe infection.
• Steroid-containing ear drops to help reduce swelling in your ear and any subsequent itching from eczema.
• Aluminium acetate ear drops to help to reduce swelling in your ear.

Most ear drops will contain a combination of steroids, antibiotics and antifungals and some come in a spray rather than ear drops. You may need to have your ear cleaned and any discharge or wax removed by your doctor or nurse before using ear drops to treat an infection. You may be asked to lie down or tilt you head to the side with your affected ear facing upwards when you use ear drops. Sometimes, it’s advised to keep still for ten minutes after using ear drops or a spray.

It may be difficult to get ear drops into your ear if your ear is swollen, so your doctor or nurse may apply the treatment using an ear wick. An ear wick is ribbon gauze or a sponge wick, which is placed in your ear and absorbs the drops when they are applied. This allows the ear drops to stay in constant contact with the affected part of your ear. The ear wick is usually left in place for a couple of days, before your doctor or nurse removes it. The ear wick is usually fitted and removed in hospital.

Alternatively, your doctor or nurse may smear a small strip of gauze dressing with antibiotic ointment and gently place it in your ear canal. You may be shown how to remove the dressing yourself.

Prevention of outer ear infection

You can help to prevent an outer ear infection by taking steps to keep your ears clean and dry.

The following tips can help to reduce your risk of having an outer ear infection.

• Don't lie with your head underwater in the bath.
• Put cotton wool smeared with petroleum jelly in your ears before you wash your hair or have a shower.
• Keep hairspray or shampoo away from your ears.
• Dry your ears with a hair dryer (on the lowest heat setting) after washing your hair.
• Don’t use cotton buds or other objects to clean your ear canal.
• Never pick your ears with your fingernails.
• Wash your hands before touching your ears.
• If you regularly use ear plugs in your workplace, make sure you use a clean pair every day.
• Use ear plugs when you go swimming.

Produced by Natalie Heaton, Bupa Health Information Team, September 2012.

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