The tonsils are two small glands that sit on either side of the throat. In young children, they help to fight germs and act as a barrier against infection.
When the tonsils become infected, they isolate the infection and stop it spreading further into the body.
As a child's immune system develops and gets stronger, the tonsils become less important and usually shrink. In most people, the body is able to fight infection without the tonsils.
It's rare for complications to occur as a result of tonsillitis. Some of the problems that can occur are outlined below.
Middle ear infection
A middle ear infection (otitis media) is where the fluid in the middle ear, between the eardrum and inner ear, becomes infected by bacteria. In most cases, the infection clears by itself.
Quinsy is an abscess (a collection of pus) that develops between one of the tonsils and the wall of the throat. It's a rare complication of tonsillitis that often affects teenagers and young adults. If one develops quinsy, the symptoms will become rapidly worse. Symptoms include:
- a worsening sore throat, usually on one side
- a high temperature of 38C (100.4F) or above
- difficulty opening the mouth
- pain and difficulty swallowing, which may lead to drooling saliva
- difficulty speaking or changes to the voice
- bad breath
- earache on the affected side
- headache and feeling generally unwell
- swelling around the face and neck
Only one in 1,000 children with tonsillitis will go on to develop quinsy. It's treated with a combination of antibiotics and surgery to drain the pus from the abscess.
Persistent or recurring tonsillitis (chronic tonsillitis) may cause breathing difficulties during sleep. This is known as obstructive sleep apnoea (OSA).
OSA that's due to chronic tonsillitis tends to affect children more than adults. Your child won't usually wake up during sleep, but their deep sleep will be disturbed. This can make them feel very tired during the day.
Children affected by sleep apnoea will often snore or gasp loudly as they sleep.
If your child develops sleep apnoea as a result of tonsillitis, a tonsillectomy (surgical removal of the tonsils) will usually be recommended.
Other complications of tonsillitis are very rare and usually only occur if an underlying bacterial infection is left untreated. They include:
- Scarlet fever – a condition that causes a distinctive pink-red skin rash
- Rheumatic fever – this causes widespread inflammation throughout the body, leading to symptoms such as joint pain, rashes and jerky body movements
- Glomerulonephritis – an infection (swelling) of the filters in the kidneys that can cause vomiting and a loss of appetite