Mouth Sores or Mucositis

Aprobado por la Junta Editorial de Cancer.Net, 01/2020

A person with cancer may have swelling inside the mouth and throat that can lead to painful mouth sores. This condition is called mucositis.

Tell your health care team if you have pain, mouth sores, or other changes in your mouth during cancer treatment. Relieving side effects is an important part of cancer care and treatment. This is called palliative care or supportive care.

What causes mouth sores?

Understanding the cause of your mouth sores will help you better manage them with your health care team. Chemotherapy, radiation therapy to the head and neck area, and bone marrow/stem cell transplantation can all cause mouth sores.

In the case of radiation therapy, symptoms may not develop right away. After radiation therapy is completed, it may take time for your mouth sores to improve. 

Mouth sores may also be a sign of graft-versus-host disease, a common side effect of a bone marrow/stem cell transplant.

How are mouth sores treated?

The best way to manage mouth sores is to prevent them or treat them early. If you are receiving chemotherapy, sucking on ice chips right before and during treatment may prevent mouth sores. Visit a dentist that specializes in cancer care before starting radiation therapy to the head or neck area.

Your doctor may also recommend pain relief strategies, like a mouthwash solution called magic mouthwash, magic mud, or triple mix. Ingredients in this mouthwash may vary, but it typically includes an antihistamine, anesthetic, an antacid, antibiotics, and/or an antifungal. You may be prescribed prescription pain medicine or they may suggest over-the-counter acetaminophen. Avoid taking aspirin during cancer treatment unless your doctor tells you otherwise. Your health care team may use a prescription liquid medication called palifermin (Kepivance). This medicine is given by vein (intravenously; IV). It can be used before and after certain treatments to reduce the risk of mucositis.

It’s important to continue to eat and drink regularly during cancer treatment, but mouth sores may make it uncomfortable. To help, take your pain medicine 30 minutes before you eat or drink. Talking with a registered dietitian can be very helpful to get other strategies to help with mouth sores. For instance, they can help figure out whether you need to take food supplements, such as protein shakes, to get the nutrition you need.

It is a good idea to take special care of your mouth during cancer treatment. The following tips may help:

  • Brush your teeth gently with fluoride toothpaste several times a day. If the mouth sores are severe, use an oral sponge on a stick, instead of a toothbrush.

  • Floss gently.

  • Rinse or gargle with a solution of saltwater and baking soda. Try mixing 1/2 teaspoon of salt plus 1/2 teaspoon of baking soda in a glass of water.

  • Avoid mouth rinses with alcohol in them.

  • If you wear dentures, lessen the time that you wear them. Avoid wearing them at night and consider removing them between meals.

  • Choose foods that require little or no chewing.

  • Avoid acidic, spicy, salty, coarse, and dry foods.

  • Try drinking through a straw to help avoid irritating your mouth sores

  • Other strategies undergoing further study using clinical trials include the use of cryotherapy (the use of cold) or low level laser therapy. Let your doctor know if you are interested in participating in these types of studies.

Talk with your doctor, nurse, or other health care team member if you are having mouth sores. They can help you find solutions that will help ease pain and make sure you are getting the nutrition you need. 

Related Resources

Did You Know that Cancer Treatment Can Affect Your Mouth?

Nutrition Recommendations During and After Treatment

Side Effects of Chemotherapy

Side Effects of Radiation Therapy

Managing Eating Challenges After Head and Neck Cancer Treatment

More Information

National Cancer Institute: Oral Complications of Chemotherapy and Head/Neck Radiation