Help for Painful Mouth Sores on Chemo

Image © Dana Rothstein/Dreamstime

Chemotherapy is one of the therapies used to treat advanced colorectal cancer. This class of drugs works to destroy fast multiplying cells, such as cancerous ones. However, the cells lining your entire digestive tract also regenerate quickly, which makes them susceptible to the devastating effects of the chemotherapy drugs. These drugs cannot differentiate a healthy, oral mucosa cell from a rapidly dividing cancerous one in your colon.

Mucositis -- painful mouth sores -- is a possible side effect of chemotherapy and more common in women than in men.

Some factors can increase your chances of developing mouth sores on chemotherapy to include:

  • Chronic dehydration 
  • Poorly fitting dentures or partials
  • A history of poor oral hygiene
  • A history of prior chemotherapy and development of mucositis
  • Human immunodeficiency virus (HIV) or AIDS

Prevention if Possible

Well before you start chemotherapy, there are a few actions you can take to help reduce your chance of developing mouth sores. Start practicing good oral hygiene to include brushing your teeth and flossing at least once daily. Salt water mouth rinses should be done before and after you eat, as well as at bedtime.

If you have any dental problems, visit your dentist and get them resolved at least one month prior to starting treatment. Similarly, if you have dentures or partials that are not quite fitting right, make sure to get them adjusted or get a new pair fit prior to your chemotherapy.

Ill fitting dentures or partials can set the stage for mouth sores and discomfort.

Ice Chips During Chemo

During your chemotherapy session, suck on ice chips while the medication is being administered. This form of therapy, also known as cryotherapy, can help shrink the blood vessels in your mouth during treatment, which essentially blocks the amount of chemotherapy drug making it to the sensitive tissues of your mouth.


Watch and Report

Mucositis might start as a dry, burning feeling in your mouth or throat. It can rapidly progress to a pain with other symptoms to include:

  • Red, inflamed gum tissue or tongue
  • Bleeding from your mouth or a coppery taste in your mouth
  • Visible white patches on your inner cheeks or tongue
  • Difficulty or pain with talking or swallowing
  • Ulcerations or sores on your cheeks, lips or tongue

Report any of these symptoms to your oncologist as soon as you notice them. Left untreated, severe cases of mucositis can lead to an infection, which can delay your cancer treatment.

What to Avoid

There are a few things that can exacerbate your mouth sores and your pain. You will want to avoid any spicy or acidic foods until your mouth heals. Things such as citrus (including orange juice), spicy peppers and herbs are all off the menu. Likewise, avoid:

  • Smoking or chewing tobacco
  • Drinking alcohol or using alcohol based mouthwashes
  • Whitening toothpastes, strips, or rinses
  • Hard bristled toothbrushes
  • Vaseline based lip balms or glycerin mouth swabs

    Treatment Options

    Even when oral care is the last thing in the world you want to do, frequent oral care throughout the day is recommended. If you avoid brushing or rinsing because of the pain, your sores can easily get infected and more pain and mucositis will ensue.

    If possible, increased protein ingestion will help your mouth to regenerate and heal tissues. Eating might not sound that appetizing with your mouth pain, but maintaining adequate protein intake is important. You can get mouth-friendly liquid protein in shakes or smoothies with whey or casein proteins, in soft scrambled eggs, or even in lentil soup.

    Although there are a few prescription medications specifically designed to help with mouth sores, they are not FDA approved for people undergoing colorectal cancer treatment. The prescription medications are tailored to people who have head, neck and blood cancers at this time. 

    Your doctor can prescribe a lidocaine based rinse, that might help to numb your mouth for a short time and provide pain relief. Likewise, some people are ordered to swish and spit out milk of magnesia or Mylanta, to help neutralize any acids and promote oral comfort. 

    It is not recommended that you take any over the counter non-steroidal anti-inflammatory drugs, such as ibuprofen or aspirin, as they can increase your risk of bleeding, which is not good if the chemotherapy is already decreasing your personal blood-clotting agents, the platelets in your blood.

    If these remedies do not provide relief, you can talk to your doctor about prescription medications such as carafate (Sucralfate) swishes, stomach acid neutralizers, and prescription medications for pain relief.


    National Cancer Institute. (n.d.). Oral Complications of Chemotherapy and Head/Neck Radiation–For Health Professionals.  Accessed online September 30, 2015.

    Oral Cancer Foundation. (n.d.). Mucositis. Accessed online September 28, 2015.

    Continue Reading