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Light Therapy for Oral Mucositis

What is light therapy?

Light therapy, or photobiomodulation, is the use of low-level laser and LED light to prevent or treat oral mucositis. Light therapy can decrease swelling, reduce pain, and promote tissue healing. 

Mucositis is swelling and irritation of the lining of the digestive system. This condition can be caused by cancer treatments including chemotherapy and radiation. Oral mucositis, sometimes called stomatitis, is irritation and sores (ulcers) that occur in the lining of the mouth including cheeks, gums, lips, or tongue. 

Learn more about mouth and throat sores.

Benefits of light therapy for oral mucositis

Child patient receiving light therapy

Light therapy can be used to prevent and treat mouth pain and inflammation caused by oral mucositis.

Sores in the mouth and throat are a common side effect of cancer treatment. Certain treatments have a higher risk of mucositis. These include radiation therapy, stem cell (bone marrow) transplant, and certain chemotherapy medicines.

Mucositis can cause pain and make it hard for patients to eat or drink. In some cases, this can result in dehydration and weight loss and increase your child’s risk for gastrointestinal tube placement (feeding tube). Mucositis can also increase the risk of infection and hospitalization.

Light therapy for oral mucositis is quick and painless. The goal is to reduce swelling and discomfort and promote tissue healing. In some cases, your care team may recommend light therapy to help prevent mouth and throat sores before they develop.

Learn how light therapy is used at St. Jude.

Illustration showing different grades of mucositis from grade 1 through grade 4

Diagnosis of oral mucositis

Your care team will do an exam of your child’s mouth and throat before the start of light therapy. They will also ask about your child’s pain and their ability to eat and drink. 

The care team will grade the oral mucositis on a scale of 1 to 4. Grade 1 is mild, and Grade 4 is most severe. The grade will help guide the treatment.   

These exams will be done regularly to track oral mucositis over time and see how well the therapy is working. 

What to expect during light therapy

Light therapy is easy to apply and can be done in your child’s hospital room or in an outpatient setting. A trained health care provider will do the treatment. Light therapy may be done up to 5 times a week. 

Light therapy uses a painless low-level laser and LED light that applies red light to areas of tissue. 

  • The red-light probe is aimed at the areas of concern on the outside and inside of the oral cavity. 
  • Each site is treated for approximately 1 minute. 
  • Depending on the areas treated, each session can take 5-10 minutes.

Your care team will plan the treatments and let you know what to expect.

Your child can eat and drink as usual after light therapy. Follow your care team’s instructions for mouth care.

Possible side effects of light therapy

There are no major risks associated with the light therapy. The treatment is quick and painless. 

There is a very small risk of irritation caused by the light. Your child will be given glasses to wear during treatment to make sure the light does not bother their eyes.

Tips to help manage oral mucositis

It is not always possible to prevent mouth and throat sores. Ways to help manage oral mucositis include:

  • Brush teeth with soft bristle toothbrush.
  • Use toothpaste with fluoride.
  • Use mouth rinses recommended by the care team. Do not use alcohol-based mouth washes.
  • Apply lip moisturizer or ointment.
  • Drink plenty of water.
  • Do not smoke cigarettes or use tobacco products.
  • Eat foods high in calories and protein.
  • Choose foods that are easy to chew and swallow. 
  • Avoid foods and beverages that can irritate the mouth. These include spicy or acidic foods, alcoholic beverages, and foods rough in texture.

Let your care team know if your symptoms get worse or do not improve.

Questions to ask your care team

  • Is my child at higher risk for mouth and throat sores?
  • What symptoms should I watch for?
  • How often and for how long will my child need light therapy?
  • What special mouth care does my child need?
  • Are there other treatments for oral mucositis?

Key points about light therapy

  • Light therapy uses a painless low-level laser and LED light to prevent or treat oral mucositis.
  • Oral mucositis (stomatitis) is inflammation and sores in the mucous membranes that line the mouth and throat. 
  • Mucositis is a common side effect of cancer treatments including chemotherapy and radiation.
  • The goal of light therapy is to reduce swelling and discomfort and promote tissue healing. 
  • Light therapy is quick, painless, and easy to apply.
  • Always follow your care team’s instructions for mouth care.


Reviewed: February 2024