How does chemotherapy affect the mouth and throat?

This fact sheet is part of a section about childhood cancer. To access the rest of the content in this section, see Childhood cancer. 

The lining of the mouth and throat becomes weak during chemotherapy treatment and may lead to inflammation and ulcers. This is called mucositis. Mucositis lessens the desire to eat, drink and swallow and it may also lead to septicaemia (bacteria entering the bloodstream). Good mouth care will help avoid infection and will increase comfort.

What is good mouth care?

• brushing the teeth using a soft-bristled toothbrush and toothpaste at least twice a day. This helps to stop plaque build-up and prevent gum disease
• make sure your child's toothbrush is clean and replace it every one to two months
• before a visit to the dentist, tell the dentist that your child is having chemotherapy
• tell your doctor if your child is having trouble with their teeth
• always tell your doctor before making a dental appointment
• keep lips moist by using creams often, including after brushing. Creams such as lanolin and soft paraffin will protect against drying and chapping

When is mouth soreness likely to happen?

Mouth soreness is likely to happen seven to ten days after chemotherapy has begun. This is the time when the blood cell counts are likely to be lowest, and the lining of the mouth will be weak.

What about eating and drinking?

There is advice about food and drink for children with sore mouths in:

• Sore mouth & throat in childhood cancer - advice about nutrition

What are the signs of a sore mouth?

If your child can't tell you their mouth is sore, these are the signs to look for:

• drooling (in younger children)
• difficulty speaking or opening the mouth
• refusing food and drink because of pain when eating
• difficulty swallowing
• dry or cracked lips
• pale, rigid gums
• redness and / or swelling of the gums
• bleeding gums
• mouth ulcers

How can you help make mouth care fun?

Involve brothers and sisters in the game of mouth care.

• role play with a dolly or teddy
• use praise and encouragement; ask for kisses to smell the sweet, fresh breath
• play with the swabs, pretending to paint pictures inside the mouth
• encourage independence by allowing younger children to hold the swab, put on the gel etc.

Where to go for more information and support

Acknowledgements