Mucositis

What happens in mucositis

The lining of the mouth and gut replaces itself every few days. Chemotherapy and radiation kill rapidly dividing cells, so they damage this lining along with cancer cells. Inflammation follows, the surface thins and breaks down into ulcers, and bacteria on the surface make the inflammation worse. Healing starts once the treatment stops and the lining regrows.

Mucositis can affect the whole digestive tract:

• Oral mucositis: the mouth and throat. It is the most visible form.
• Esophageal mucositis: pain and burning when swallowing.
• Gastrointestinal mucositis: the stomach and intestines, causing GI discomfort such as cramping, bloating, nausea and diarrhea.

Symptoms

Mouth and throat

• redness, soreness or burning, often starting on the inside of the cheeks, sides of the tongue and floor of the mouth
• shallow ulcers, sometimes covered with a white or yellow layer
• mouth pain when eating, drinking or talking
• pain on swallowing and difficulty swallowing
• bleeding, thick saliva and altered taste

Gut

Gastrointestinal mucositis causes diarrhea, abdominal cramps, nausea, bloating and, with rectal involvement, rectal pain. So yes, mucositis can cause GI discomfort, and severe diarrhea can lead to dehydration.

Grades

Doctors use the World Health Organization scale for oral mucositis:

Causes and risk factors

Treatments that cause mucositis

• Chemotherapy, especially 5-fluorouracil, methotrexate, cytarabine, doxorubicin, melphalan and high-dose regimens.
• Radiation to the head and neck, which causes mucositis in most people treated for head and neck cancer, often severe and lasting the whole course.
• Radiation to the abdomen or pelvis, causing intestinal and rectal mucositis.
• High-dose therapy before a stem cell or bone marrow transplant.
• Targeted drugs such as mTOR inhibitors (everolimus), which cause distinctive aphthous-like mouth ulcers.

What raises the risk

• poor oral hygiene, gum disease or ill-fitting dentures
• smoking and alcohol
• dry mouth
• malnutrition and dehydration
• reduced kidney function, which slows drug clearance
• certain genetic variations in drug-handling enzymes, such as DPD deficiency with 5-fluorouracil

Causes of mucositis in women

The causes are the same in women and men. Women do appear to develop mucositis and other chemotherapy side effects somewhat more often with certain drugs, including 5-fluorouracil. Women having chemotherapy for breast cancer or pelvic radiation for cervical, uterine or ovarian cancer may develop oral or intestinal mucositis. Non-cancer causes of mouth inflammation, such as aphthous ulcers, iron or B12 deficiency and lichen planus, also affect women and should be distinguished from treatment-related mucositis.

Diagnosis

Mucositis is diagnosed by looking in the mouth during cancer treatment. The team will grade it, check for infection that can look similar, and ask about pain, eating and bowel habits. Swabs may test for:

• Candida, which causes oral thrush with white, wipeable patches
• Herpes simplex virus, which can reactivate during treatment and cause painful ulcers on the lips, gums and palate. See herpes simplex stomatitis

In transplant patients, mouth sores appearing later may be graft-versus-host disease.

Treatment

Mouth care

• brush gently with a soft toothbrush twice a day and replace it often
• rinse several times a day with bland rinses, such as salt and baking soda water (about 1/2 teaspoon of each in 8 oz or 240 ml of water)
• avoid alcohol-based mouthwashes
• keep the lips moist with a bland balm
• remove dentures if they rub

Pain relief

• topical anesthetic or "magic mouthwash" rinses prescribed by the cancer team
• benzydamine mouthwash, which also helps prevent mucositis from head and neck radiation
• doxepin rinse in some centers
• acetaminophen (paracetamol), and opioids, including patient-controlled morphine, for severe pain. Ask your team before using NSAIDs, which can affect platelets and kidneys

Eating and drinking

• choose soft, moist, cool or lukewarm foods: yogurt, smoothies, mashed potato, eggs, soups
• avoid spicy, salty, acidic, crunchy and very hot foods, and alcohol
• use a straw for drinks
• nutritional supplement drinks help maintain weight
• a feeding tube may be needed for severe, prolonged mucositis, especially with head and neck radiation

Treating gut mucositis

Antidiarrheal medicine (as directed by the team), fluids and electrolytes, and octreotide for severe chemotherapy-related diarrhea.

Treating infection

Antifungals for thrush, antivirals for herpes, and urgent antibiotics if fever occurs with a low white cell count (neutropenia).

Prevention

The MASCC/ISOO guidelines support several measures:

• Dental check-up before treatment to fix infections and sharp teeth.
• Oral cryotherapy: sucking ice chips for about 30 minutes during short infusions of bolus 5-fluorouracil or high-dose melphalan. Cold narrows blood vessels so less drug reaches the mouth.
• Photobiomodulation (low-level laser therapy): for people having stem cell transplants or head and neck radiation.
• Palifermin: a growth factor given before some transplant conditioning regimens.
• Benzydamine mouthwash during head and neck radiation.
• Good oral hygiene throughout.

Outlook

Chemotherapy-related mucositis usually peaks about a week after a cycle and heals within 2 to 3 weeks. Radiation mucositis builds through the course and heals 2 to 4 weeks after the last session. Severe mucositis can force doctors to reduce or delay cancer treatment, which is why prevention matters. Long-term dry mouth (xerostomia) after head and neck radiation is a separate, often lasting problem.

Frequently asked questions

What is mucositis?

Mucositis is inflammation and ulceration of the moist lining of the digestive tract, most often the mouth and gut, caused mainly by chemotherapy and radiation. It causes mouth sores, pain when eating, and diarrhea, and usually heals within a few weeks after treatment ends.

Can mucositis cause GI discomfort?

Yes. Gastrointestinal mucositis inflames the stomach and intestinal lining, causing cramps, bloating, nausea, diarrhea and sometimes rectal pain. Severe diarrhea during cancer treatment can quickly cause dehydration and should be reported to your cancer team the same day.

How long does mucositis last?

After chemotherapy, symptoms usually start in 5 to 10 days and heal within 2 to 3 weeks. With radiation, mucositis builds over the course and settles 2 to 4 weeks after the final session. Infection, smoking and poor nutrition can slow healing.

What is the best mouthwash for mucositis?

Bland rinses of salt and baking soda in water are recommended for routine care. Benzydamine helps prevent and ease mucositis from head and neck radiation. Your cancer team may prescribe anesthetic or combination rinses for pain. Avoid alcohol-based mouthwashes, which sting and dry the mouth.

Is mucositis the same as stomatitis?

Stomatitis means any inflammation of the mouth, from infections, ulcers, allergies or vitamin deficiencies. Mucositis specifically describes the damage caused by cancer treatment, and it can extend beyond the mouth into the whole digestive tract.