Symptom Management, Palliative Care, or Supportive Care to relieve side-effects is an important part of cancer care and treatment and should always form part of the overall treatment plan.

Xerostomia, more commonly called “dry mouth” occurs when the glands in the mouth and digestive system that secrete saliva for digestion do not make enough saliva, or spit, to keep the mouth moist. Saliva is needed for chewing, swallowing, tasting, and talking, so a dry mouth will make doing these activities more difficult.

Signs and Symptoms

Dry mouth often causes dental problems because saliva helps maintain a healthy balance of bacteria in the mouth; without enough saliva, the bacteria and other organisms in the mouth grow too quickly. This can cause sores and mouth infections, including an infection called thrush that is caused by an overgrowth of yeast.

Signs and symptoms of dry mouth include:

  • A sticky, dry feeling in the mouth
  • Thick, stringy saliva
  • Pain or a burning sensation in the mouth or on the tongue
  • Cracks in the lips or at the corners of the mouth
  • A dry, rough tongue
  • Difficulty chewing, tasting, or swallowing
  • Difficulty speaking

Saliva also washes away acids and food particles left in the mouth after eating, which means that a lack of saliva can cause gum disease and cavities (tooth decay).


Chemotherapy and radiation treatments can cause dry mouth by damaging the salivary glands.

Chemotherapy causes dry mouth by making the saliva thicker, which is usually a temporary symptom that clears up around 2-8 weeks after treatment ends.

Radiation therapy to the head, face, or neck may also cause dry mouth. It can take 6 months or longer for the salivary glands to start producing saliva again after the radiation therapy ends. Some individuals experience improvement during the first year after radiation treatment, but many individuals will continue to experience some level of long-term dry mouth, especially if the radiation therapy was directed at the salivary glands.

In addition, a disease called graft-versus-host disease (GVHD) (in which cells transplanted from a donor recognise the patient’s body as foreign and attack it), may cause dry mouth and mouth sores.

Antidepressants, medications called diuretics that increase urination, and some painkillers can also cause dry mouth. Dry mouth can also occur as a result from a mouth infection such as thrush or from dehydration.

Management and Treatment

Relieving side effects is an important part of total cancer care and treatment, which is why you should discuss any symptoms your child is experiencing, new symptoms and changes in symptoms with their Oncology Team so that they can work out a regimen of palliative or supportive care for them.

Take your child to see a dentist before they start any radiation treatment or chemotherapy to check the health of their mouth and teeth. It’s important to schedule this as soon as you can because if they need to have teeth removed, it should be done at least 3-4 weeks before treatment begins so their mouth has time to heal.

Although dry mouth cannot be prevented, some treatments can help, including:

  • Medication that prevents or lessens the side effects of radiation treatment
  • Saliva substitutes and mouth rinses
  • Medications that stimulate the salivary glands
  • Sucking on sugar-free sweets or chewing sugarless gum will also stimulate the salivary glands


The following tips may help with the management of dry mouth and the prevention of dental problems:

  • Encourage your child to brush their teeth after each meal and at bedtime with a soft-bristle toothbrush and fluoride toothpaste. Soak the brush in warm water for them first to make the bristles even softer.
  • Encourage your child to floss gently daily
  • Encourage your child to rinse their mouth with salt and baking soda 4-6 times a day, especially after meals (half a teaspoon of salt and half a teaspoon of baking soda in one cup of warm water).
  • Encourage your child to use fluoride rinses and gels when their radiation therapy starts. Fluoride rinses and gels are an important part of caring for the health of your child’s mouth during cancer treatment.
  • Encourage your child to drink sips of water throughout the day, and to use artificial saliva to moisten their mouth.
  • Use a cool mist humidifier in your child’s bedroom, especially at night.
  • Some dentists may prescribe medication to increase saliva production or rinses to fight infections in the mouth.

Consider the following tips for eating with a dry mouth:

  • Encourage your child to drink a lot of water throughout the day. Carrying a bottle of water may help them drink enough.
  • Give your child soft, moist foods that are cool or at room temperature.
  • Moisten dry foods with broth, sauces, butter, or milk.
  • Do Not give your child dry, coarse, or hard foods.
  • Do Not give your child acidic or spicy foods that burn the mouth.
  • Do Not give your child sticky, sugary foods and drinks.
  • Do Not give your child drinks with caffeine (such as coffee, tea, and cola), and acidic juices.