Mucositis is a condition that causes pain and inflammation of the surface of the mucous membrane. The mucous membrane is the soft layer of tissue that lines the digestive system including the:
- mouth
- stomach
- anus (back passage)
Mucositis develops as a side effect of radiotherapy and chemotherapy. The radiation used during radiotherapy and the powerful cancer-killing medicines used in chemotherapy can damage the cells of the mucous membrane.
However, in radiotherapy, mucositis will only occur if the high-energy beams of radiation are directed at the areas of the body where the mucous membrane is present, such as the mouth and oesophagus (the passageway that connects the mouth to the stomach). Therefore, patients who are receiving radiotherapy for other types of cancer, such as breast cancer, will not usually develop mucositis.
Types of mucositis
There are two types of mucositis:
- oral mucositis occurs inside the mouth and can cause painful mouth ulcers (sores) to develop
- gastrointestinal mucositis occurs inside the digestive system and often causes diarrhoea
How common is mucositis?
Mucositis can be a very common side effect of certain types of cancer treatment. For example, four out of ten people who have chemotherapy as part of their cancer treatment will develop some degree of mucositis.
Mucositis is more common among certain types of cancer. For example, one in three people who have radiotherapy or chemotherapy for head or neck cancers will develop mouth problems, such as oral mucositis.
At least three-quarters 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 oral mucositis.
Radiation-induced mucositis is less common in cancer treatments that do not involve the head or neck, but it can still be a problem.
Outlook
Oral mucositis can be very painful, but the ulcers that are caused by the condition will heal without treatment and will not leave scars.
The symptoms of mucositis should begin to improve three or four weeks after chemotherapy or radiotherapy has finished. However, if you have had radiotherapy that is aimed directly at your mouth, it may take six to eight weeks before your symptoms start to improve.
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 management and monitoring.
Many people with mucositis find it painful to swallow food and require alternative feeding methods, 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 it can be a life-threatening condition that requires emergency treatment.
Preventing mucositis can often be difficult. However, treatments are available that can shorten the duration of the condition and reduce the severity of its symptoms. See Mucositis - treatment and Mucositis - prevention for more information.
