Mouth Sores or Mucositis

Approved by the Cancer.Net Editorial Board, 09/2015

Mucositis is swelling inside the mouth and throat that can lead to painful ulcers and mouth sores.

Talk with your doctor if you notice pain or other changes in your mouth during cancer treatment. Relieving side effects, also called symptom management or palliative care, is an important part of cancer care and treatment.

Causes of mouth sores

There are several possible causes of mouth sores related to cancer and cancer treatment. Understanding the cause may help you and your health care team manage this side effect.

  • Chemotherapy. Up to 40% of people receiving chemotherapy experience mouth sores.

  • Radiation therapy to the head and neck area

  • Bone marrow/stem cell transplant. Mouth sores are a possible sign of graft-versus-host disease, which is a side effect of these procedures.

Managing mouth sores

The best way to manage mouth sores is to prevent them or treat them early. Here are some suggestions and options for preventing and treating mouth sores:

  • Suck on ice chips immediately before and during each chemotherapy treatment. This may prevent mucositis caused by certain types of chemotherapy.

  • Your doctor may recommend specific pain-relief strategies if you develop mouth sores. Options include the following:

    •  A mouthwash solution that contains lidocaine, sometimes called magic mud, magic mouthwash, or triple mix

    • Over-the-counter drugs, such as acetaminophen (Tylenol). However, it is important to avoid taking aspirin during cancer treatment unless your doctor tells you otherwise.

    • Prescription pain medicine

It is also wise to take special care of your mouth during cancer treatment. The following suggestions below may help. Also, learn more about dental and oral health during cancer treatment.

  • Visit an oncologic dentist before starting treatment if you will be receiving radiation therapy to the head and neck. An oncologic dentist is experienced in treating people with head and neck cancer.

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

  • Floss gently.

  • Rinse or gargle with a solution of saltwater and baking soda. Try a solution of 1/2 teaspoon of salt plus 1/2 teaspoon of baking soda in a glass of water. Avoid mouth rinses that have alcohol in them.

  • Lessen the time that you wear your dentures. Avoid wearing them at night, and consider removing them between meals to help reduce mouth irritation.

  • Choose foods that require little or no chewing.

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

More Information

Side Effects of Chemotherapy

Side Effects of Radiation Therapy

Side Effects

Additional Resource

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