Otitis externa is a condition that causes inflammation (redness and swelling) of the external ear canal, which is the tube between the outer ear and eardrum.
Otitis externa is often referred to as “swimmer’s ear” because repeated exposure to water can make the ear canal more vulnerable to inflammation.
It is more common in hot and humid climates (or at the end of the British summer) and five times more common in swimmers. It is most frequently seen in the 45-75 year-old age group.
Symptoms of otitis externa include:
- ear pain, which can be severe
- itchiness in the ear canal
- a discharge of liquid or pus from the ear
- some degree of temporary hearing loss
Usually only one ear is affected.
With treatment, these symptoms should clear up within a few days. However, some cases can persist for several months or longer.
When to see your GP
You should see your GP if you think you may have otitis externa.
Your GP will ask you about your symptoms and whether you regularly use any items that are inserted into your ears, such as hearing aids or ear plugs. They may also examine inside your ear using an instrument called an otoscope.
If you have recurring episodes of otitis externa that haven’t responded to treatment, your GP may take a swab of the inside of your ear. This will be tested to help determine what type of infection you have, if any, so that appropriate medication can be prescribed.
What causes otitis externa?
Most cases of otitis externa are caused by a bacterial infection, although the condition can also be caused by irritation, fungal infections and allergies.
There are a number of things that can make you more likely to develop otitis externa, including damaging the skin inside your ear and regularly getting water in your ear.
Getting water in your ear is particularly significant because this can cause you to scratch inside your ear, and the moisture also provides an ideal environment for bacteria to grow.
Who is affected?
Otitis externa is relatively common. It is estimated that around 1 in 10 people will be affected by it at some point in their lives.
The condition is slightly more common in women than men and is most often diagnosed in adults aged 45 to 75.
People with certain long-term (chronic) conditions, such as eczema, asthma or allergic rhinitis, are at greater risk of developing the condition.
How otitis externa is treated
Otitis externa does sometimes get better without treatment, but it can take several weeks. Your GP can prescribe ear drop medication that will usually improve the symptoms within a few days.
There are a number of different types of ear drops that may be used to treat otitis externa, but they all tend to be used several times a day for about a week.
Your GP may refer you to a specialist for further treatment and advice if symptoms are severe or they fail to respond to treatment.
Preventing otitis externa
To help reduce your chances of developing otitis externa, you should avoid inserting cotton wool buds and other things into your ears (including your fingers), as this can damage the sensitive skin in your ear canal.
If you are a regular swimmer, consider using ear plugs when swimming or wearing a swimming cap to cover your ears and protect them from water.
You should also try to avoid getting water, soap or shampoo into your ears when you have a shower or bath.
The aim of treatment is:
- To settle symptoms.
- To cure infection.
- To reduce risk of recurrence.
- To prevent complications.
If the condition is painful then appropriate analgesia is required.
Topical treatment is recommended, unless there is spread with cellulitis or the patient is systemically unwell. In most cases the choice of topical intervention does not appear to influence the therapeutic outcome significantly.
Packing with ribbon gauze or a sponge ear wick soaked in an astringent such as aluminium acetate or steroid helps to reduce oedema of the ear canal.
One study reports that antibiotic-steroid combination has a superior effect.
If packing to reduce oedema is not used, advise patients with a swollen ear canal to lie on one side with the affected ear up and to keep this position for 10 minutes after the introduction of ear drops.
Treatment with an an antibacterial or corticosteroid should be for no longer than seven days, because of risk of a secondary fungal infection or possible allergy developing.
Contact sensitivity with topically applied ear drops is most commonly due to antibiotics, especially aminoglycosides and preservatives.
Management for children is the same as for adults.
Complications of otitis externa are uncommon, but some can be very serious.
One rare complication of otitis externa is malignant otitis externa, which is where an infection spreads from the ear canal into the surrounding bone.
This requires prompt treatment with antibiotics and sometimes surgery, as it can be fatal if left untreated.
Most cases of otitis externa resolve within a few days of starting treatment. If malignant otitis externa is suspected, urgent referral to ENT should be made.