Mucositis

Mucositis is a condition that causes pain and inflammation of the surface of the mucus membrane. The mucus membrane is the soft layer of tissue that lines your digestive system, including your mouth, stomach and anus (back passage).

Mucositis develops as a side effect of radiotherapy and chemotherapy. Both the radiation that is used in radiotherapy, and the powerful cancer-killing medicines that are used in chemotherapy, can damage the cells of the mucus membrane.

Types of mucositis

There are two types of mucositis:

• Oral mucositis: occurs inside the mouth and often causes painful mouth ulcers to develop.
• Gastrointestinal mucositis: develops inside the digestive system and often causes diarrhoea. 

How common is mucositis?

Mucositis can be a very common side effect for certain types of treatment.

For example, almost all people who receive high-dose radiotherapy to treat mouth or neck cancers, will develop the most severe symptoms of oral mucositis, known as grade three or grade four mucositis.

Also, 75% of people who receive high-dose chemotherapy because they are undergoing a stem cell transplant (more commonly known as a bone marrow transplant) will develop grade three or grade four mucositis.

See the Diagnosis section for more information about the grading system that is used for mucositis.

Mucositis is less common in cancer treatments that do not involve the head or neck, but it can still be a problem. For example, 40% of all cancer patients will develop some degree of mucositis.

Prognosis

The most serious cases of mucositis can lead to a number of associated health complications, some of which are occasionally life threatening. Therefore, the condition requires careful monitoring and management.

Many people with mucositis find it painful to swallow food (dysphagia) and require alternative methods of feeding, such as a feeding tube. A lack of suitable nutrition, combined with the symptoms of diarrhoea, can quickly cause a person to become malnourished and dehydrated.

Sometimes, mouth ulcers can become infected with bacteria. In people with a weakened immune system (as is usually the case in those receiving high-dose chemotherapy or radiotherapy) the infection can spread to the blood and then on to other organs. This is known as sepsis and can be a life-threatening condition that requires emergency treatment.

Preventing mucositis can often be difficult but there are treatments that can shorten the duration of the condition and reduce the severity of its symptoms.