Mouth Sores and Dry Mouth

Cells in the mouth can be affected by chemotherapy and radiation therapy to the head and neck. As such, it’s important to keep the mouth and teeth as clean as possible. Your child will feel more comfortable, and you can help prevent mouth sores or other infections.

General mouth care

Have your child brush their teeth with a soft toothbrush after each meal and before bed.

Rinse the mouth with water after brushing. Do not use mouthwashes that contain alcohol. Alcohol dries out the mouth.

If a dry mouth is a problem, have your child suck on sugar- free hard candies or ask your health care provider about mouthwashes or other products for dry mouth.

Caring for mouth sores (Stomatitis)

Some chemotherapy medicines and radiation therapy to the head and neck can cause mouth sores. The inside of the mouth may be red or may have sores that can be painful. You may also see white plaques (small raised areas) in the mouth that may be from a fungal infection.

If mouth sores are a problem:

  • Give your child plenty of fluids.
  • Have your child drink fluids with a straw.
  • Avoid spicy or acidic foods.
  • Give your child foods that are cold or at room temperature.
  • Try soft, tender, or pureed (beaten or blended) foods.
  • Avoid dry or coarse foods.
  • Cut food into small pieces.
  • Rinse the mouth with water or a mouthwash recommended by your healthcare provider several times a day.
  • Avoid mouthwash that contains alcohol.

Your healthcare provider may give your child a medication to treat a fungal infection in the mouth (thrush), and/or a pain medication if the sores are painful. Call your healthcare provider if your child cannot drink fluids, swallow, or if your child’s medicine does not help take away the pain.


  • Avoid food and drinks with extreme temperatures that can hurt the mouth and throat. Lukewarm or room-temperature foods and beverages may be better tolerated.
  • Avoid acidic foods and beverages like citrus and tomato juices that can burn the mouth and throat. Fruit nectar, especially pear nectar, may be well tolerated.
  • Avoid salty or spicy foods that can burn or sting. Offer blander foods instead.
  • Try soft foods that are easy to chew, or consider mixing food in a blender with fluid (water, broth, gravy) to make it easier to eat.
  • Experiment with liquid nutritional formulas. A registered dietitian can provide suggestions and samples of products to try.
  • Encourage using a straw to drink fluids and thinned pureed food instead of a spoon.
  • Ask your child’s doctor or nurse about medicine you can give before meals to numb the mouth or throat.
  • Avoid commercial mouthwash containing alcohol, which can burn.

Dealing with a dry mouth

Radiation therapy to the head or neck area can reduce the flow of saliva and cause a dry mouth, making it harder to chew and swallow foods. Dry mouth can also change the way foods taste.


  • Try very sweet or tart foods and beverages (but avoid tart foods if the child has a sore mouth or throat).
  • Sucking on hard candy, popsicles, or chewing gum can help produce more saliva. Sugar-free candies and gum are better to avoid tooth decay.
  • Serve foods with sauces, gravies, or butter to help make them moist and easier to swallow.
  • Prepare soft and pureed foods.
  • Use lip balm to keep your child’s lips moist.
  • Sipping on liquids throughout the day may help keep the mouth moist.
  • Ask the doctor about products that can help with a dry mouth.