Ear infection, outer

Page last reviewed: 13/07/2011

Otitis externa is a condition that causes inflammation (swelling) of the external ear canal. This is the tube between the outer ear and eardrum (tympanic membrane).

Otitis externa is sometimes called 'swimmer's ear' or 'tropical ear'. This is because it can sometimes be caused by getting water inside your ear canal and it is often more common in humid conditions.

Otitis externa can also be caused by an infection or an allergic reaction to something that comes into contact with the external ear canal. In many cases of otitis externa, the cause is unknown.

How common is otitis externa?

Each year, otitis externa affects around 1% of the population. Although anyone can get otitis externa, it is slightly more common in women than in men.

People with certain chronic (long-term) conditions are at greater risk of developing otitis externa. Such conditions include:

 

  • eczema (a skin condition)
  • asthma (a condition that causes the airways to become inflamed, making breathing difficult)
  • allergic rhinitis (a condition where an allergic reaction causes the inside of your nose to become inflamed)

Otitis externa can be easily treated with eardrops and analgesics (painkillers). However, in rare cases, complications can develop, such as the formation of abscesses (pus-filled growths), which can form in and around your affected ear, and cellulitis (a bacterial infection). See Otitis externa - complications for more details.

There are a number of simple measures that may prevent otitis externa from recurring. See Otitis externa - prevention for more information.

Page last reviewed: 13/07/2011

There are three different types of otitis externa:

  • localised otitis externa
  • acute diffuse otitis externa
  • chronic otitis externa

Each type of otitis externa has slightly different symptoms, which are described below.

Localised otitis externa

Localised otitis externa (furunculosis) is an infection of a hair root (follicle) in your ear canal. The symptoms of the condition may include:

  • a small red pimple in your ear canal which may have white or yellow pus at its centre. In rare cases, the pimple progresses to become a boil, which can obstruct your ear canal
  • severe ear pain (particularly when you move your ear). The pain may seem out of proportion to the size of the pimple and, in rare cases, the pimple or boil bursts, causing the pain to stop suddenly
  • occasional hearing loss, which can occur if the pimple or boil is obstructing your ear canal
  • tender and painful glands behind your ears, known as post-auricular lymph nodes

Acute diffuse otitis externa

Acute diffuse otitis externa is a more widespread inflammation (swelling) of the ear canal, which causes a skin rash that can extend to your outer ear (pinna) and your eardrum (tympanic membrane).

Acute diffuse otitis externa is the most common form of otitis externa.

Otitis externa is defined as acute (severe but short lasting) if it lasts for less than three weeks. The symptoms of acute diffuse otitis externa may include:

  • redness and swelling of your outer ear (pinna) and ear canal, which can be very painful
  • scaly skin in and around your ear canal, which may peel off
  • discharge from your ear, which can be either thin and watery or pus-like
  • itching and irritation in and around your ear canal
  • tenderness when you move your ear or jaw
  • swollen and sore glands (lymph nodes) in your throat
  • some hearing loss
  • ear ache (otalgia)

Chronic otitis externa

Like acute diffuse otitis externa, chronic otitis externa is a more widespread inflammation (swelling) of your ear canal, which causes a skin rash that can spread throughout your ear.

Otitis externa is defined as chronic (long lasting) if it lasts for longer than three months. In severe cases, the condition can last for several years.

The symptoms of chronic otitis externa are similar to those of acute diffuse otitis externa, but they may also include:

  • a constant itch in and around your ear canal, which is often the main symptom
  • discomfort and pain in your ear which becomes worse when you move it
  • a thin and watery discharge that comes from your ear
  • a lack of ear wax (cerumen)
  • a build-up of thick, dry skin in your ear canal, known as stenosis, which can narrow your ear canal and affect your hearing
Discharge
Discharge is when a liquid such as pus oozes from a part of your body.
Swelling
Inflammation is the body's response to infection, irritation or injury, which causes redness, swelling, pain and sometimes a feeling of heat in the affected area.

Page last reviewed: 13/07/2011

There are several different causes of otitis externa, as well as a number of factors that may provoke the condition, making it more likely to occur. However, in many cases of otitis externa, particularly chronic otitis externa, the cause is unknown.

Possible causes of otitis externa include:

  • a lack of ear wax (cerumen)
  • increased temperature
  • high humidity
  • damage to the ear canal caused by hearing aids or cotton wool swabs

Details of specific causes of the three types of otitis externa, and the provoking factors of the condition, are outlined below.

Localised otitis externa

Localised otitis externa is caused by an infection of a hair root (follicle) in your ear canal. The infection is usually the result of a type of bacteria known as Staphylococcus aureus.

Acute diffuse and chronic otitis externa

The causes of acute diffuse otitis externa and chronic otitis externa are essentially the same. However, in many cases of chronic otitis externa, the cause is unknown. Some of the known causes are described below.

Bacterial infection

Bacterial infection is a common cause of acute otitis externa. The bacteria that cause the infection are usually either Pseudomonas aeruginosa or Staphylococcus aureus. In cases of chronic otitis externa, there may be a chronic, low-grade infection, which is difficult to diagnose.

Seborrhoeic dermatitis

Seborrhoeic dermatitis is a common skin condition where the areas of your skin that are naturally greasy (sebaceous), such as the side of your nose, your forehead and your scalp, become irritated and inflamed (swollen). This may be a contributory factor in the development of otitis externa.

Middle ear infection

If you have had a middle ear infection, such as otitis media, your ear may have been producing discharge over a prolonged period of time. In some cases, the discharge may cause otitis externa.

Fungal infection

The species of fungus that can cause otitis externa includes the Aspergillus variety and the Candida albicans variety, which also causes thrush.

If you have been using antibacterial eardrops or aural corticosteroids (ear medication that relieves swelling) over a long period of time to treat another infection, you may develop a secondary fungal infection that can cause otitis externa.

Allergic and irritant reactions

Otitis externa can sometimes be caused by an allergic or irritant reaction to something that comes into contact with your ears, such as ear medication, ear plugs or shampoo. If you wear a hearing aid, you may find that it makes the inside of your ear sweaty, which sometimes can cause otitis externa.

Incomplete treatment

If you are being treated for acute otitis externa and you do not complete your treatment, you may go on to develop chronic (long-term) otitis externa.

Factors that can provoke otitis externa

The following factors are not direct causes of otitis externa, but they may make developing the condition more likely.

Ear damage

Your ear canal is very sensitive and can easily become damaged through scratching, excessive cleaning, ear syringing and the insertion of cotton buds. You may also damage your ear canal by incorrectly or excessively wearing hearing aids, ear plugs or ear phones.

Excessive moisture

You are more likely to get otitis externa if liquid gets into your ear canal. Swimming (particularly in dirty or polluted water), sweating and humid environments may increase your risk of getting otitis externa.

Chemicals

Your chances of getting otitis externa are increased if you use products that contain chemicals in or near your ears, such as hair sprays, hair dyes and earwax softeners.

Underlying skin conditions

As well as seborrhoeic dermatitis being a potential risk factor for otitis externa, underlying skin conditions, such as psoriasis, eczema and acne, can also increase your risk of developing the condition.

Allergic conditions

If you have allergic rhinitis or asthma, you may also be at higher risk of developing otitis externa.

Weak immune system

If you have a condition that weakens your immune system, such as diabetes, HIV or AIDS, or if you have been having certain cancer treatments, such as chemotherapy, you may be at higher risk of developing otitis externa.  

GlossaryInflammation
Inflammation is the body's response to infection, irritation or injury, which causes redness, swelling, pain and sometimes a feeling of heat in the affected area.

Page last reviewed: 13/07/2011

See your GP if you think you may have otitis externa. They will ask you about your symptoms and whether you use any items that are inserted into your ears, such as hearing aids or ear plugs.

Ear examination

Your GP may use an instrument that has a light at one end, known as an otoscope, to examine your outer ear (pinna) and your ear canal. They will check your ear for redness and inflammation (swelling).

During the examination of your ear, your GP may also check for flaky skin, any visible sign of a fungal infection and whether or not your eardrum (tympanic membrane) is perforated (has a hole in it).

Ear swab

If you have recurring episodes of otitis externa or if medication that you have previously been prescribed has failed to treat the condition, your GP may take a sample from your ear using an ear swab. This will help determine whether your infection is bacterial or fungal so that your GP can prescribe the appropriate medication.

GlossaryBacteria
Bacteria are tiny, single-celled organisms that live in the body. Some can cause illness and disease and some others are good for you.

Page last reviewed: 13/07/2011

Several simple medications can be used to effectively treat most cases of otitis externa. If you have localised otitis externa (where a hair root in your ear canal becomes infected), you may not need treatment as the condition may clear up on its own.

General advice

Whatever type of otitis externa you have, follow the general self-care advice below to assist your treatment:

  • Avoid getting your affected ear wet, for example by wearing a shower cap while showering and bathing. Remove any discharge or debris by gently swabbing your ear with cotton wool, being careful not to damage it.
  • Remove anything from your affected ear that may cause an allergic reaction, such as hearing aids, earplugs and earrings.
  • Treat any underlying skin conditions that may aggravate your otitis externa, such as seborrhoeic dermatitis, psoriasis or eczema.
  • Relieve ear pain using painkillers such as paracetamol or ibuprofen. Do not take ibuprofen if you are asthmatic or have stomach problems, such as stomach ulcers (past or present). If you are unsure whether you should take it, check with your GP, practice nurse or pharmacist. Children under 16 years of age should not take aspirin.

Inform your GP or practice nurse if you have an allergic disposition (a tendency to have allergies). Eardrops that contain certain substances, such as neomycin or propylene glycol, are more likely to cause an allergic reaction than others. Your GP, practice nurse or pharmacist will be able to advise you about which type of eardrops are most suitable for you.

Localised otitis externa

If you have localised otitis externa, the condition may heal on its own in a few days. You can relieve any pain using analgesics (painkillers), such as paracetamol or ibuprofen.

Do not take ibuprofen if you are asthmatic or have stomach problems, such as ulcers. Children under 16 years of age should not take aspirin.

It may help to put a warm towel or flannel on your affected ear.

Without treatment, it is likely that the pimple or boil in your ear canal will eventually burst, drain and heal by itself. However, you may not want to wait for this to happen because you may be in considerable pain and discomfort.

See your GP if you have localised otitis externa that has not healed by itself after about a week. If your infection is severe, oral antibiotics may be prescribed. In rare cases, where the pimple or boil is very painful and swollen, your GP may suggest draining it to remove the pus. Your GP may remove the pus using a surgical needle, or you may be referred to a specialist.

Do not scratch your ear or use cotton buds to clean your ear, as this will cause pain in your ear canal.

Acute diffuse otitis externa

If you have acute diffuse otitis externa, analgesics (painkillers), such as paracetamol or ibuprofen, will help relieve any pain you have. Do not take ibuprofen if you have asthma or stomach problems, such as ulcers (past or present). Children under the age of 16 should not take aspirin.

It is likely that you will need treatment to relieve the inflammation caused by acute diffuse otitis externa. Your GP may prescribe a topical ear preparation in the form of eardrops. Topical treatments are those that are applied directly to the area that needs to be treated.
 
There is a wide range of eardrops made up of different ingredients that can treat acute diffuse otitis externa. These include:

  • antibiotic preparations
  • corticosteroid preparations
  • antifungal preparations
  • antibiotic and corticosteroid preparations
  • acidic preparations

In most cases of acute otitis externa, topical treatments are effective in treating the infection. However, you may need to take strong analgesics (painkillers) during the first few days of treatment. If you are prescribed antibiotic and steroid eardrops, you can expect your symptoms to start improving approximately six days after treatment has started.

If you have severe acute diffuse otitis externa, your GP may refer you for specialist treatment. This may involve using one or more of the methods below to remove earwax and allow eardrops to work more effectively: 

  • syringing or irrigation, where water is injected through the nozzle of a syringe into the ear canal to dislodge and wash away any ear wax
  • microsuction, where a small suction device is used to remove any ear wax, discharge and debris from your outer ear (pinna) and ear canal
  • dry swabbing to gently mop out any ear wax from your ear canal

You may also need an ear wick, which is a soft cotton gauze plug that is covered with medication and inserted into your ear canal. An ear wick allows the medication to reach the end of your ear canal. It should be changed every two or three days. This type of treatment should only be carried out by a specialist.
 
In very severe cases of infection, an oral antibiotic, such as flucloxacillin, may be prescribed. 

Chronic otitis externa

In most cases of chronic otitis externa, the exact cause of the condition cannot be identified. If this is the case, your GP will probably prescribe a topical preparation in the form of eardrops to be used for seven days. The eardrops will probably contain a corticosteroid (medication to relieve swelling) without an antibiotic.
 
As chronic otitis externa is a long-term condition, your treatment may have to continue for two to three months. If your condition has not improved after this time, your GP may prescribe antifungal eardrops instead.

If your chronic otitis externa appears to be caused by an underlying skin condition, such as seborrhoeic dermatitis, psoriasis or eczema, your GP may prescribe a treatment for the skin condition before treating otitis externa.

If your otitis externa appears to be caused by a fungal infection, a topical antifungal preparation in the form of eardrops may be prescribed.

You will only need to have specialist treatment for chronic otitis externa if:

  • your condition does not improve following the treatment prescribed by your GP
  • your ear canal is in danger of closing up
  • you have had an allergic reaction and you need a skin patch test to determine what you are allergic to
GlossaryAntibiotic
Antibiotics are medicines that can be used to treat infections caused by micro-organisms, usually bacteria or fungi. Examples of antibiotics include amoxicillin, streptomycin and erythromycin.
Discharge
Discharge is when a liquid such as pus oozes from a part of your body.
Pain
Pain is an unpleasant physical or emotional feeling that your body produces as a warning sign that it has been damaged.
Swelling
Inflammation is the body's response to infection, irritation or injury, which causes redness, swelling, pain and sometimes a feeling of heat in the affected area.

Follow these steps to apply eardrops effectively.

  • Gently remove any discharge, ear wax or debris from your outer ear and ear canal using a twist of cotton wool. Do not insert cotton wool buds into your ear.
  • Warm the eardrops by holding the bottle in your hand for a few minutes before applying them. This will help bring the eardrops up to body temperature. This will prevent any dizziness caused by applying cold eardrops.
  • To insert the eardrops, lie on your side with your affected ear facing up. The eardrops should fill your ear canal.
  • Gently push and pull your ear to work the drops in and to get any trapped air out.
    Stay lying down for 3-5 minutes to ensure that the eardrops do not come out of your ear canal. If this is not possible, try gently plugging the ear for a few minutes using a piece of cotton wool covered in petroleum jelly (Vaseline) or moistened with the eardrops.
  • Leave your ear canal open to dry.

Page last reviewed: 13/07/2011

Complications associated with otitis externa are usually uncommon. However, the complications below can sometimes occur.

Abscesses

Abscesses are pus-filled growths that can form in and around your affected ear after an infection. They usually heal on their own but, in some cases, your GP may need to drain the pus from them.

See the Health A-Z topic about Abscesses for more information.

Stenosis of the ear canal

Stenosis is the name given to the build-up of thick, dry skin in your ear canal, which can occur if you have chronic otitis externa. It can affect your hearing because the build-up of skin makes your ear canal narrower. In rare cases, it can cause deafness. Stenosis of the ear canal can be treated using eardrops for chronic otitis externa.

Inflamed or perforated eardrum

If you have acute diffuse otitis externa or chronic otitis externa, it is possible for the infection to spread to your eardrum (tympanic membrane). In some cases, the infection may cause pus to build up inside your inner ear and may rupture (tear) your eardrum.

If you have a ruptured or perforated eardrum, you may be able to taste any medication that you put into your ear and you may be able to blow air out of your ear when you pinch your nose.

A perforated eardrum (where there is a hole in it) usually heals by itself in a couple of months. Avoid getting any liquid inside your ear until your eardrum has completely healed. As you will not be able to use eardrops, your GP may prescribe oral antibiotics to treat your otitis externa.

You can use analgesics (painkillers), such as paracetamol or ibuprofen, to minimise any pain caused by a perforated eardrum. Putting a warm towel or flannel to your ear may also help. Do not take ibuprofen if you have asthma or if you have stomach problems, such as ulcers. Children who are under 16 years of age should not take aspirin.

See the Health A-Z topic about Perforated eardrum for more information.

Cellulitis

Cellulitis is a bacterial skin infection that can occur as a result of otitis externa. It can happen when bacteria, which normally live harmlessly on the surface of your skin, enter your skin's deeper layers through damaged areas, such as those caused by otitis externa. Cellulitis can spread from the layers of your skin to surrounding tissues, glands (lymph nodes) and into your bloodstream, but it is easily treated using antibiotics.

If you have cellulitis of the neck or the face, you may be prescribed oral antibiotics to treat otitis externa.
 
See the health A-Z topic about Cellulitis for more information.

Malignant otitis externa

Malignant otitis externa is a serious but very rare complication of otitis externa, in which the infection spreads to the bone that surrounds your ear canal.

Malignant otitis externa usually affects adults more than children. In particular, adults who are immunocompromised (have a weakened immune system) have an increased risk of developing malignant otitis externa. This includes people having chemotherapy treatment or who have a chronic (long-term) health condition, such as diabetes, HIV or AIDS.

If you have malignant otitis externa, you may have the following symptoms:

  • severe ear pain and headaches
  • exposed bone may be visible in your ear canal
  • facial nerve palsy, where your face droops on the side of the affected ear

Without treatment, malignant otitis externa can be fatal. However, it can be effectively treated using antibiotics and surgery to remove any damaged tissue.

Page last reviewed: 13/07/2011

You can take a number of steps to avoid otitis externa and prevent it from recurring. These are described below.

Avoid damaging your ears

  • Do not insert cotton wool buds or other objects into your ears. Wax works its way out naturally and cotton buds should only be used to sweep around your outer ear (pinna).
  • If earwax build-up is a problem, have it removed by a healthcare professional.

Keep your ears dry and clean

  • Do not let water, soap or shampoo get inside your ears when you wash them. Wear a shower cap while you shower or bathe.
  • After washing, dry your ears using a hairdryer on a low setting. Never push the corners of a towel into your ears to dry them because this can cause damage.
  • If you swim regularly, wear a swimming hat that covers your ears or use ear plugs.

Treat and prevent other skin conditions

  • If you develop otitis externa and you have an allergic disposition (a tendency to get allergies), tell your GP or practice nurse. Eardrops that contain certain substances, such as neomycin or propylene glycol, are more likely to cause an allergic reaction than others. Your GP, practice nurse or pharmacist can advise you about which eardrops are most suitable for you.
  • If you have an allergic reaction to anything that is placed inside your ears, such as hearing aids, earplugs or earrings, remove the item. A mild allergic reaction will usually clear up on its own. Using hypoallergenic products (products that have a lower potential for causing allergic reactions) may also help.
  • Seek medical advice for any other skin conditions, such as psoriasis or eczema, so they can be treated using the right medication.
  • Try using acidifying eardrops or spray to help keep your ears clean, particularly before and after swimming. They may help prevent otitis externa recurring, and are available without a prescription in most pharmacies.

Content provided by NHS Choices www.nhs.uk and adapted for Ireland by the Health A-Z.

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