Skin Reactions

Mouth Sores (Mucositis)

Mouth sores, known as oral mucositis, are small cuts or sores that form in the mucosa, which is the lining of the inside of the mouth. The cells of the mucosa divide rapidly, as do cancer cells. So when chemotherapy and radiation therapy are administered to attack cancer cells, they also may attack the cells of the mucous membrane and lead to mouth sores.

Mouth sores can affect the gums, tongue, roof of the mouth or lips. They sometimes begin as mild pain or burning, followed by white patches that may become large, red lesions. Chemotherapy-related mouth sores usually develop within a few days after treatment begins and heal within two to four weeks after chemotherapy ends. Mouth sores caused by radiation usually develop two to three weeks after the start of radiation therapy, and it may take four to six weeks for them to heal. Pain may range from mild to severe, sometimes making it difficult to talk, eat or swallow. The pain from mouth sores can have far-reaching effects if the discomfort prevents you from eating. If the results are life-threatening, you may require feeding tubes.

Managing mouth sores involves taking steps to prevent them, to minimize pain or discomfort and to help them heal. Taking good care of your teeth and gums is essential, and you should brush your teeth and floss several times a day. If you will be receiving chemotherapy, you may also want to suck on ice chips during the first half-hour of your treatment. This will reduce the likelihood of mouth sores because the cold limits the amount of the drug that reaches your mouth. If mouth sores develop, your doctor may suggest rinsing your mouth with special solutions or prescribe a medication that coats the lining of your mouth. Topical pain medications are an option as well. The table near the bottom of the page summarizes some of the ways in which you can control your symptoms.

Talk to your doctor about the risk of mouth sores for the type of treatment you will receive. Call your doctor when you first notice any type of sore in your mouth. The sooner you treat mouth sores, the better chance you have of preventing them from becoming severe.

Medications associated with mouth sores:

  • alemtuzumab (Campath)
  • asparaginase (Elspar)
  • busulfan (Myleran)
  • capecitabine (Xeloda)
  • carboplatin (Paraplatin)
  • cetuximab (Erbitux)
  • cyclophosphamide (Cytoxan)
  • cytarabine (Cytosar-U)
  • daunorubicin (Cerubidine)
  • docetaxel (Taxotere)
  • doxorubicin (Adriamycin)
  • epirubicin (Ellence)
  • etoposide (VePesid, Toposar, Etopophos)
  • everolimus (Afinitor)
  • fluorouracil (Adrucil)
  • gemcitabine (Gemzar)
  • gemtuzumab ozogamicin (Mylotarg)
  • hydroxyurea (Hydrea, Droxia)
  • idarubicin (Zavedos)
  • interleukin 2 (Proleukin)
  • irinotecan (Camptosar)
  • lomustine (CeeNU)
  • mechlorethamine (Mustargen)
  • melphalan (Alkeran)
  • methotrexate (Rheumatrex, Trexall)
  • mitomycin (Mutamycin)
  • mitoxantrone (Novantrone)
  • oxaliplatin (Eloxatin)
  • paclitaxel (Taxol)
  • pentostatin (Nipent)
  • procarbazine (Matulane)
  • thiotepa (Thioplex)
  • topotecan (Hycamtin)
  • vinblastine (Vinblastin)
  • vincristine (Oncovin)

Ways to prevent and manage mouth sores

Symptom Treatment Suggestions
Routine oral care
• Regularly remove and clean your dentures.
• Check your mouth twice each day with a small flashlight and tongue blade.
• Clean your mouth and teeth gently with a soft toothbrush, cotton swab or mouth swab.
• Rinse your mouth with salt or baking soda.
• Use gentle mouthwashes regularly; your doctor will let you know which ones are good for
• Keep lips moist with K-Y jelly or lip balm; do not use Vaseline.
Pain relief
• Suck on ice chips.
• Apply topical, local anesthetic solutions or jelly, such as lidocaine.
• Use oral analgesia or intravenous analgesia with opioids as prescribed by your doctor.
• Rinse with medicated mouthwashes (dexamethasone, nystatin) to decrease inflammation
  and yeast infections.
• Use topical corticosteroids (dexamethasone solution, triamcinolone 0.1 percent in Orabase)
  on irritated areas on the tongue, mouth or lips.
Enhance healing
• Maintain good nutrition, including high-protein and high-calorie foods, which are soft and/or
  semi-liquid. Liquid supplements such as Boost and Ensure can also be used.
Diet habits
• Drink a large amount of fluids (aim for two to three quarts per day) and use a straw to avoid
  mouth sores while drinking.
• Eat soft foods and cut in small pieces.
• Eat foods at room temperature or slightly warm.
What to avoid
• Do not eat hot, spicy, greasy, fried, coarse or rough-textured foods.
• Do not consume very hot or very cold beverages and foods.
• Avoid citric juices or foods containing acid, such as tomatoes, oranges and lemons.
• Avoid all alcoholic beverages and tobacco products.
• Do not use liquid medications containing alcohol, such as some cough medicines, if they are
  not essential.