Chemotherapy May Cause Oral Mucositis


Oral mucositis is probably the most common, debilitating complication of cancer treatments, particularly chemotherapy and radiation. It can lead to several problems, including pain, nutritional problems as a result of inability to eat, and increased risk of infection due to open sores in the mucosa. It has a significant effect on the patient’s quality of life and can be dose-limiting (i.e., requiring a reduction in subsequent chemotherapy doses). 

Radiation therapy or chemotherapy may cause mucositis (tissue swelling) in your mouth. You may have symptoms such as:

  • Mouth pain.
  • Mouth sores.
  • Infection.
  • Bleeding, if you are getting chemotherapy. Radiation therapy usually does not lead to bleeding.

With chemotherapy, mucositis heals by itself when there is no infection. Healing usually takes 2 to 4 weeks. Mucositis caused by radiation therapy usually lasts 6 to 8 weeks, depending on how long you have radiation treatment.


Oral mucositis is a common complication of chemotherapy. It begins 5-10 days after the initiation of chemotherapy and lasts 7-14 days. Chemotherapy-induced oral mucositis causes the mucosal lining of the mouth to atrophy and break down forming ulcers.

Patients typically experience the following:

  • Oral pain
  • Erythema
  • Difficulty opening the mouth
  • Difficulty eating, drinking, and speaking
  • Difficulty with mouth care regimens


Diagnosis is based on the symptoms the patient is experiencing and the appearance of the tissues of the mouth following chemotherapy, bone marrow transplants or radiotherapy. Red burn-like sores or ulcers throughout the mouth is enough to diagnose mucositis.

The severity of oral mucositis can be evaluated using several different assessment tools. Two of the most commonly used are the World Health Organization (WHO) Oral Toxicity score and the National Cancer Institute Common Toxicity Criteria (NCI-CTC) for Oral Mucositis. While the NCI system has separate scores for appearance (erythema and ulceration) and function (pain and ability to eat solids, liquids, or nothing by mouth), the WHO score combines both elements into a single score that grades the severity of the condition from 0 (no oral mucositis) to 4 (swallowing not possible such that patient needs supplementary nutrition). Another scale developed in 1999, the Oral Mucositis Assessment Scale (OMAS) has been shown to be highly reproducible between observers, responsive over time, and accurate in recording symptoms associated with mucositis. The OMAS provides an objective assessment of oral mucositis based on assessment of the appearance and extent of redness and ulceration in various areas of the mouth.



If you have oral mucositis, it is very important you have a good oral hygiene routine because it can reduce the severity of your symptoms and how long you experience them.

Below is some general advice on good oral hygiene. However, always follow any advice your cancer treatment team gives you if it differs from the advice below.

  • Brush your teeth every morning and evening and after every meal.
  • Use a toothbrush with soft bristles.
  • Replace your toothbrush regularly. Most toothbrushes need to be replaced every three months.
  • Floss your teeth at least once a day or as advised by your treatment team.
  • Rinse your mouth five or six times a day using a bland rinse. A bland rinse is a mixture of water and sodium bicarbonate (baking soda) or a mixture of water and salt (to make a saline solution). Your treatment team will be able to advise you about the type of bland rinse suitable for you.
  • Do not use a mouth rinse that contains alcohol.
  • Avoid tobacco, alcohol and irritating foods, such as hot, spicy, acidic or rough foods.
  • Use a water-based moisturiser to protect your lips.
  • Make sure you drink plenty of fluids throughout the day. A minimum of 1.2 litres (2 pints) is the recommended daily amount.

Ice cubes

Sucking ice cubes or ice chips is sometimes recommended as a way of providing relief from the symptoms of oral mucositis.

The healthcare professionals treating you will advise you about whether ice cubes could help you or not.

Pain relief

Oral mucositis is often painful, but there are several kinds of painkillers available that you can try. You may be given painkillers in the form of a mouth rinse, gel or spray.

If a painkiller is not effective, other medicines can be tried alongside it, or a stronger painkiller can be used. Worsening pain does not always mean you will need to be admitted to hospital, and in most cases you can take the painkilling medication yourself at home.

If a simple painkiller such as paracetamol doesn’t work, you may then be prescribed a stronger type of painkiller, such as codeine. If this is still not effective, a stronger opioid can be prescribed, such as morphine.

Non-steroidal anti-inflammatory drugs (NSAIDs) may provide pain relief for some people. However, if you are receiving some types of chemotherapy, NSAIDs could damage your kidneys and affect the way they work. For this reason, you should only take painkillers as advised by your treatment team.


Palifermin is a type of medication that has proved to be successful in treating people having a stem cell transplant (bone marrow transplant), which usually includes chemotherapy or radiotherapy.

Palifermin encourages the growth of new cells on the lining of the mucous membrane. This growth is thought to reduce the severity of your symptoms and encourage any ulcers to heal faster. Palifermin also stops sores forming, so can be used to prevent, as well as treat, mucositis.

Palifermin is given by injection. You should receive an injection once a day for three days before your chemotherapy or radiotherapy, and then for three days afterwards, for a total of six doses.

Common side effects of palifermin include:

  • skin rash, itchiness and redness
  • an increase in the thickness of the lining of your mouth or tongue
  • a change in the colour of your mouth or tongue
  • aching joints
  • altered taste

Less common side effects include swelling of the face or mouth.

The side effects should pass after you have completed the course of palifermin.

Low-level laser therapy (LLLT)

Low-level laser therapy (LLLT) is another treatment that can reduce the severity of oral mucositis. It involves focusing low-energy lasers (beams of light) at affected tissue. LLLT is thought to work by stimulating certain cells that then help to speed up the healing process.

As LLLT requires specialist equipment and training, it may only be available at specialist cancer centres or clinics.

Infected ulcers

The mouth ulcers (sores) that mucositis causes can become infected. If this happens, your treatment team may prescribe medication for this. You may also be given a special mouth wash to use to prevent further infections.

Mucositis may increase the risk of oral thrush, which can be treated with antifungal medicines.