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Patient Education

Mouth Sores During Cancer Treatment

Cancer treatments such as radiation therapy to the head or neck, some chemotherapy agents and biological therapy can cause mouth sores. These small ulcerations and sensitive areas on the lips, tongue or gums can be painful and often lead to poor intake of food and beverages, resulting in weight loss.

Suggestions to improve nutritional intake while experiencing mouth sores:

Choose creamy-soft textures.

Examples include: avocado, baked sweet potatoes, mashed potatoes made with non-fat powdered dry milk, Greek yogurt, baby foods such as pears or prunes, cottage cheese, cream soups, macaroni and cheese and spinach soufflé.

Cook food until soft and tender.

Avoid citrus fruit and juices, spicy foods, tomato products, salty foods, raw vegetables, sharp or crunchy foods and alcoholic beverages.

Drink beverages with a straw, which can help push the drinks beyond the painful areas of your mouth.

Eat cold or room-temperature food.

Ask your dietitian or doctor if a medical food supplement such as Ensure®, Boost®, Carnation® Breakfast Essentials™ or Boost Glucose Control® is right for you.

Other tips for mouth sores:

  • Rinse your mouth every two hours for 15-20 seconds with 1 teaspoon salt + 1 teaspoon baking soda in 1 quart of water.
  • Use a cold-air humidifier at night.
  • Brush your teeth with a soft, nylon-bristled toothbrush and non-abrasive toothpaste that contains fluoride. Note that whitening toothpastes may contain hydrogen peroxide, which can irritate sore mouths.
  • Avoid mouthwashes containing alcohol or other irritants.
  • Remove and clean dentures between meals on a regular basis; if sores are present under your dentures, leave them out between meals and at night.
  • Avoid toothpicks and other sharp objects.
  • Keep lips moist with petroleum jelly, a mild lip balm or cocoa butter.
  • Ask your physician if a prescription medication rinse is right for you.
  • Notify your physician if you notice white patchy areas which may indicate yeast or fungal growth