Otitis externa usually clears within a week or so. However, sometimes it persists. This leaflet lists possible causes and treatments for persistent otitis externa.
What is otitis externa?
Otitis externa is an inflammation of the ear canal, which may be caused by infection, allergy or other causes. Symptoms include itch, ear discharge, temporary dulled hearing and pain.
Most bouts of otitis externa clear within a week or so with ear drops or sprays. These usually contain an antibiotic and a steroid medicine. The antibiotic clears infection and the steroid reduces itch and inflammation. Short-lived episodes which clear up quickly are called 'acute'.
However, in some cases the otitis externa becomes persistent (chronic). This means it lasts longer than three months. Occasionally, it can last for several years.
What are the symptoms of chronic otitis externa?
The symptoms of chronic otitis externa are similar to those of acute otitis externa. Other symptoms may include:
- Constant itch in and around your ear canal.
- Discomfort and pain in your ear.
- A discharge from your ear.
- Your hearing also being affected. This can be due to some thick, dry skin building up in your ear canal, which then narrows it.
Reasons for otitis externa becoming persistent (chronic)
There are different reasons why some people develop chronic otitis externa. These are generally the same as for people who develop acute otitis externa. However, for many people with chronic otitis externa the underlying cause in unknown.
Causes of chronic otitis externa include:
If water, shampoo, soap, hairspray, etc, get into your ears, they may may cause irritation or itch. This may cause you to scratch or poke the ear. This can damage the skin in the ear canal and cause inflammation. Inflamed skin can quickly become infected. A vicious circle may then develop. The inflammation and infection cause more itch, you then scratch which makes things worse, etc. So, despite treatment, the infection may continue if you continue to poke or scratch your ear. Therefore:
- Try not to scratch or poke the ear canal with fingers, cotton wool buds, towels, etc.
- Do not clean the ear canal with cotton buds. They may scratch and irritate,and push wax or dirt further into the ear. The ear cleans itself and bits of wax will fall out now and then.
- Try not to let soap or shampoo get into your ear canal. You can do this when you have a shower, by placing a piece of cotton wool coated in soft white paraffin (eg, Vaseline®) into the outer ear.
- Do not use corners of towels or cotton buds to dry any water that does get into the ear canal. This will push things further in. Let the ear dry naturally.
- When you swim try to keep your ears dry. You can do this by wearing a tightly fitting cap that covers the ears. Some swimmers use silicone rubber earplugs but only use them if they do not irritate the skin in your ear canal.
Let the discharge out
As a rule, do not leave balls of cotton wool in the ear canal. This stops the discharge (or debris) which needs to come out. However, if the discharge is heavy, you may need to place some cotton wool lightly in the outer part of the canal to mop up the discharge. If you use cotton wool, replace it frequently with a fresh piece.
Sometimes otitis externa does not clear because ear drops are not used correctly. You have to put them in as often as prescribed to be fully effective. If the drops come out of the ear quickly, they may not work so well. When using drops:
- Lie with the affected ear upwards.
- Put several drops in the ear, and lie in this position for 1-2 minutes.
- Press the cartilage at the front of the ear canal a few times to push the drops deep inside the ear canal.
Resistant germs (bacteria)
Some bacteria which infect the ear canal are resistant to some antibiotic ear drops. A change to a different type of ear drop may be advised if you have used the first one correctly with little improvement after a week or so. Sometimes a small sample of the discharge (a swab) is taken and sent to the laboratory. This may help to identify which germ is causing the infection and which antibiotic is best to use against this germ. If the infection is severe, antibiotic tablets may be needed in addition to drops.
Clearing the discharge may be advised
A doctor or nurse may clean the ear canal. They do this by using cotton wool on the end of a special stick. This is gently pushed inside the ear canal to mop up any discharge or debris. Some GPs and nurses are trained to do this. Sometimes a referral to an ear specialist is needed. Sometimes gentle suction or syringing is used to remove discharge lying in the ear canal. You may need a regular clear-out of discharge every few days or so until the otitis externa has gone.
A wick may be advised if the ear canal is very swollen
A wick is a piece of gauze material which is soaked in antibiotic drops. It is gently placed in the ear canal by a doctor or nurse. The wick ensures that an antibiotic is always present and reaches the inner part of the ear canal. A wick is usually changed regularly.
Still no success?
The above treatments will usually clear most cases of otitis externa. However, a doctor may consider a few other measures if it still persists.
Some people develop an allergy or sensitivity to ear drops that are used for otitis externa. The itch and discharge may then become worse rather than better. If this is suspected then a change to an ear drop low in allergy reactions may be advised. Sometimes a doctor will advise that you stop all ear drops which contain antibiotics. A steroid-only ear drop may be tried to reduce inflammation. Referral to a specialist for skin patch testing is sometimes needed. This is to find out what is causing the allergy - for example, the antibiotic, or a preservative in a particular ear drop.
Most infections of the ear canal are caused by germs (bacteria). These germs usually clear up with antibiotic drops. An uncommon cause of persistent otitis externa is due to a fungal infection. Fungal germs are not killed by antibiotics - in fact, antibiotic and steroid ear drops can make a fungal infection worse. A fungal infection may be suspected if an otitis externa does not clear with the usual treatment. A small sample (swab) may be taken to confirm the diagnosis. Fungal infections in the ear canal are difficult to treat. It may take several weeks of antifungal ear drops and/or tablets to clear a fungal ear infection.
Middle ear infections
If the ear canal is full of discharge it may be difficult for a doctor to tell whether it is from the outer ear (otitis externa) or from a middle ear infection which has come through a burst eardrum. You may be referred to a specialist if the cause is not clear.
Sometimes the inflammation in the ear canal is a local area of a skin disorder, such as a small patch of eczema or psoriasis. The symptoms in the ear may be similar to an infection, but bacteria or fungal germs are not the cause. This is uncommon but the inflammation in the ear may flare up now and then, just as skin disorders flare up from time to time. The treatment which is usually advised is steroidal ear drops whenever symptoms flare up.
Necrotising otitis externa
This is a very rare condition and you will most likely only stand a chance of getting it if you are an elderly person with diabetes or you have a problem with your immune system. The infection spreads to the underlying bone and causes swelling of the ear canal, discharge and pain. It is mainly caused by a germ called Pseudomonas aeruginosa. It usually requires a lengthy course of antibiotic ear drops and tablets.
Referral to a specialist
This may be needed for such measures as cleaning the ear canal of discharge, if a fungal infection is suspected, or for a more detailed examination of the ear.
Preventing otitis externa
Otitis externa has a tendency to come back (recur). It is less likely to recur if you follow the advice given above in the section 'Sensitive ears'. In short, try to keep the ear canal dry and avoid soap or shampoo from getting in. The most important thing is to avoid scratching or poking the ear canal with fingers, towels, cotton wool buds or anything else.
Dr Tim Kenny
Dr Laurence Knott
Dr Helen Huins