Although complications associated with otitis externa are uncommon, there is a small risk of further problems developing.

Some of the main complications of otitis externa are described below.

Abscesses

Abscesses are painful, pus-filled growths that can form in and around the 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.

Narrowing of the ear canal

If you have long-term (chronic) otitis externa, thick and dry skin can build up inside your ear canal.

This causes the ear canal to narrow (stenosis), which may affect your hearing and can even cause deafness in rare cases. However, it can usually be treated with ear drops.

Inflamed or perforated eardrum

It is possible for any infection to spread to your eardrum. In some cases, the infection may cause pus to build up inside your inner ear and may rupture (tear) your eardrum. This is known as a perforated eardrum.

Symptoms include:

• temporary hearing loss
• earache or discomfort
• a discharge of mucus from your ear
• ringing or buzzing in your ear (tinnitus)

In many cases, a perforated eardrum will heal without treatment in a couple of months. Surgery may be recommended if it shows no signs of healing after this time.

Cellulitis

Cellulitis is a bacterial skin infection that can occur after otitis externa. It's when bacteria that 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 causes affected areas of skin to become red, painful, hot and tender to the touch.

Other symptoms include:

• feeling sick
• shivering
• chills
• a general sense of feeling unwell

Most cases of cellulitis can be treated with a seven-day course of antibiotics.

If cellulitis occurs in a person who was already very ill or who is very vulnerable to the effects of infection, they may need to be admitted to hospital as a precaution.

Malignant otitis externa

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

It usually affects adults more than children. Adults who have a weakened immune system are at a particularly increased risk of developing it. This includes people having chemotherapy or who have certain long-term health conditions, such as diabetes or HIV.

There were 810 cases of malignant otitis externa seen in hospitals in England between 2012 and 2013. More than 700 of these were diagnosed in people who were 60 or older.

Signs and symptoms of malignant otitis externa can include:

• severe ear pain and headaches
• exposed bone 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.