Mouth Care for Patients Receiving Chemotherapy

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The immune system goes through changes during chemotherapy that make a child less able to fight infection.  This means any infection in the mouth could become serious.

Chemotherapy may cause the mouth to develop sores for a period of time. These mouth sores are called “mucositis” (mew koe SIE tis) or “stomatitis” (stow mah TIE tis). They are often painful and may make it hard for your child to eat and drink.  Open sores in  the mouth may also be a source of infection.

Always check with your child’s doctor before taking the child for any dental exams or dental work. There are times when dental work should not be done unless it is absolutely necessary.  Check with your health care provider before taking your child to the dentist.

Checking your child’s blood counts before any dental work is important. Your health care provider may want to prescribe antibiotics before dental work, or the dental work may need to be postponed.

Care of the Mouth and Teeth

Tooth Brushing

  • Wash your hands before and after helping your child with mouth care to help prevent infections.checking a child's mouth with a flashlight
  • Use a flashlight to look in your child’s mouth every day for mouth sores (Picture 1).
    • Look for any red, yellow or white areas and for any bleeding or sores.
    • Ask your child if any areas hurt.
    • Be sure to look at your child’s whole mouth. Check the lips, gums, tongue, under the tongue, cheeks, roof of the mouth and around the teeth.
  • Use a regular soft toothbrush. Do not use toothpicks and water irrigation devices (such as WaterPik®).
  • Help your child to brush his or her teeth at least 2 to 4 times a day, especially after breakfast and before bed. Children under age 9 should be supervised by an adult while they brush.
  • Use fluoridated toothpaste to help prevent tooth decay.
  • Brushes should be air dried.  There is no need to soak them in a special solution.

Flossing - If your child has not been taught how to floss, he should not begin flossing at this time.

Sore Lips - Use products on the lips that contain lanolin. These work well to keep lips moist and protect against damage.


  • Check with your doctor or dentist before using any mouth rinses or mouthwash froma store. Rinses that contain alcohol or heavy flavorings may sting and burn. Some may irritate the mouth while the child is on chemotherapy.
  • It is important to keep the mouth moist. A dry mouth makes it easier to get an infection or cavity. To keep the mouth moist, your child may use saline, sterile water or tap water as often as he would like to rinse and spit.
  • A sodium bicarbonate rinse may be helpful when the saliva is very thick. To make this rinse, mix 1/4 teaspoon salt and 1/4 teaspoon baking soda in 4 ounces of water.


  • Do not give your child foods and liquids that are high in sugar or acids. Examples of high-sugar or acidic drinks include sports drinks, regular and diet soda, fruit juices, sweetened teas and Kool-Aid®.
  • Dietary supplements like Pediasure® and Boost®  and some medicines taken by mouth contain a lot of sugar. Be sure to brush your child’s teeth or rinse his mouth with water after he drinks any supplements or takes medicines.
  • Do not let your child fall asleep with any foods, drinks, milk or medicine in his mouth.

Refer to the Helping Hands HH-IV-4, Dental: Teeth and Gum Careor HH-IV-29, Dental: Teeth and Gum Care for Infants and Toddlers.

What to Do If Your Child Gets Mouth Sores

Keep your child’s mouth clean.

  • Rinse every 1 to 2 hours with water, saline, sterile water or sodium bicarbonate rinse.
  • Continue with your tooth brushing routine.

Keep your child well hydrated.

  • Have your child keep a water bottle handy and take frequent sips.
  • Have your child suck on ice chips, popsicles and “slushies.”
  • Let your child drink through a straw.

Keep your child as comfortable as possible.

  • Use ice cold rinses every 1 to 2 hours.
  • Use ice packs on the neck and cheeks if it helps make your child more comfortable.
  • Give your child cold or cool foods.  Hot foods may irritate mouth sores.
  • Avoid salty, spicy, acidic or rough foods.
  • Moisten foods with cream or gravy.  Moist foods may be easier to swallow.

Offer soft foods like yogurt, cottage cheese, soup, scrambled eggs, pasta, quiche, applesauce and Jell-O®.

When to Call Your Doctor

Call your child’s doctor if you notice any of the following:

  • Discolored (red, yellow or white) areas in your child’s mouth.
  • Your child complains of pain.
  • Your child is not able to drink and seems to be getting dehydrated (dried out). Signs of dehydration include low or decreased urine output and a dry, sticky mouth.
  • Your child has a fever of 100.5º F or higher.

If you have any questions, be sure to ask your doctor, dentist or nurse.

HH-II-45 Mouth Care for Patients Receiving Chemotherapy (PDF)

Revised 9/16 Copyright 2002 Nationwide Children’s Hospital