Oral Mucositis (Mouth Sores From Chemo and Radiation)

Oral mucositis is the soreness, redness, and open sores that show up inside the mouth during chemotherapy or radiation to the head and neck. It often starts as a sunburned feeling in the cheeks or tongue, then turns into raw patches that make eating, talking, and even swallowing water hurt. If that's where you are right now, we're sorry. It's one of the hardest parts of cancer treatment, and you're not doing anything wrong. It does heal.

Short answer

Oral mucositis is inflammation and sores of the mouth lining caused by chemotherapy or head and neck radiation. It isn't contagious. Chemo sores usually start 5–10 days after a dose and heal in 2–4 weeks. Radiation sores build from week 2–3 and heal weeks after treatment. Gentle mouth care and pain control help. Call your oncology team right away for fever or if you can't eat or drink.

Not sure this is what you have? Answer five quick questions in our mouth spot checker. It compares what you see with more than 40 common conditions and tells you how soon to have it looked at.

Call your oncology team right away if:

  • You have a fever of 100.4°F (38°C) or higher during chemo, or chills. With low blood counts, mouth sores can let infection in, and a fever can be an emergency.
  • You can't eat or drink, or you're barely getting fluids down. Dehydration sneaks up fast when swallowing hurts.
  • Pain isn't controlled by what you've been given, or you're bleeding from the mouth and it won't stop.

Don't wait for your next appointment, and don't wait until morning if it's a fever. Use the after-hours number your cancer center gave you.

Who gets itVery common with head and neck radiation and high-dose chemo
After a chemo doseStarts in 5–10 days, heals in 2–4 weeks
During radiationBuilds from week 2–3, worst near the end
Contagious?No
Who manages itYour oncology team, with your dentist helping
Where oral mucositis shows up in the mouthIllustration of an open mouth showing oral mucositis: red, raw patches and yellow-white sores on the inner lips, inner cheeks, sides and underside of the tongue, the floor of the mouth, and the soft palate at the back. The gums and the hard roof of the mouth are shaded orange as places mucositis is less likely, where sores during chemo could point to a herpes infection instead.Inner upper lipHard palateless likely; think herpesSoft palateInner cheekSides and underside oftongue, floor of mouthGums around teethless likely; think herpesInner lower lipInnercheekRed, raw mucositis with yellow-white sores (soft, moveable lining)Less typical spots for mucositis
Oral mucositis favors the soft, moveable lining of the mouth. With radiation, it shows up mainly inside the area being treated. Illustration: CJ Henley, DMD.

What oral mucositis looks like

People usually feel it before they see it. The first sign is often a burning or scalded feeling, a bit like you drank coffee that was too hot. Then the lining of the mouth changes:

  • Redness that looks shiny or swollen, often on the inside of the cheeks, the inner lips, or the sides of the tongue.
  • Open sores that may be covered with a yellow-white or gray film. The film is a layer of dead cells and fibrin, not pus, and it shouldn't be scraped off.
  • Patches that merge. In more severe cases, small sores join into large raw areas.
  • Thick saliva or mucus, especially with radiation, plus bleeding when you brush if your platelets are low.

So what do chemo mouth sores look like compared with radiation mouth sores? They look much alike. The difference is mostly where they are. Chemo can affect the whole mouth. Radiation sores stay inside the area being treated, so someone getting radiation for a throat or tongue cancer may have sores on one side or toward the back, and none at the front.

Oral mucositis grades: the WHO 0 to 4 scale in plain words

Your oncology nurses will probably look in your mouth at visits and give the mucositis a grade. There are several mucositis grading scales. The one used most often is the World Health Organization (WHO) scale, which grades by what you see and by what you can eat. That second part is why your team keeps asking how meals are going.

Oral mucositis grading scale, WHO grades 0 to 4Five panels showing a patch of cheek lining getting worse from left to right. Grade 0: normal pink lining, no changes. Grade 1: soreness and redness, no open sores. Grade 2: redness and small sores, can still eat solid food. Grade 3: larger sores, liquids only. Grade 4: severe sores, can't eat or drink by mouth. Grades 3 and 4 are marked as reasons to call the oncology team.Grade 0Grade 1Grade 2Grade 3Grade 4No changesLining looksnormalSoreness andrednessNo open soresRedness andsmall soresCan still eatsolid foodLarger soresLiquids onlySevere soresCan't eat ordrink by mouthKeep up mouth care, tell your teamTell your teamCall your oncology team today
The WHO oral mucositis grading scale, simplified. Grades 3 and 4 mean eating and drinking are seriously affected. Illustration: CJ Henley, DMD.
GradeWhat it looks and feels likeEating
0Nothing yetNormal
1Sore, red, maybe a burning feeling. No open sores.Normal, maybe some foods sting
2Red with soresYou can still eat solid food
3Bigger or more sores, quite painfulLiquids only
4Severe, widespread soresCan't eat or drink enough by mouth. Often needs IV fluids or a feeding tube for a while.

You may also hear about other scales, like the National Cancer Institute's CTCAE, which your team uses to track side effects in a standard way. The idea is the same. Higher numbers mean more trouble eating and more need for help.

When mucositis starts and how long it lasts

The timing depends on the treatment. Chemo mucositis tends to come and go with each cycle. Radiation mucositis builds slowly over the weeks of treatment and takes a while to settle after the last session.

Timeline of oral mucositis during a chemotherapy cycle and during a 6 to 7 week course of head and neck radiationTop chart, one chemotherapy cycle over 4 weeks: no sores for the first few days after the dose, sores start around days 5 to 10, are worst about 1 to 2 weeks after the dose, and heal as blood counts recover, often by about day 21. Bottom chart, head and neck radiation given 5 days a week for about 7 weeks: redness and soreness begin around weeks 2 to 3, sores build and are usually worst near the end of treatment and in the week or two after, then heal over roughly 2 to 4 weeks after the last treatment, sometimes longer.Chemotherapy: one cycleDay 0Day 7Day 14Day 21Day 28Chemo dosemouth feels fine at firstSores startdays 5–10Worst about 1–2 weeks after the dosewhen blood counts are often lowestHeals as blood counts recoveroften by about day 21Head and neck radiation: about 6–7 weeksRadiation, 5 days a weekStartWk 2Wk 4Wk 6Wk 8Wk 10Wk 12Last treatmentRedness, sorenessweeks 2–3Usually worst near the endand for a week or two afterHeals over~2–4 weeks, sometimes longer
Typical timing of mouth sores from chemo and radiation. Your own timeline depends on your drugs, doses, and radiation plan. Illustration: CJ Henley, DMD.

When does mucositis start after chemo, and how long does it last?

Mucositis from chemo usually shows up about 5 to 10 days after a dose. It's typically worst over the following week, which often lines up with the time your white blood cell count is lowest. As counts recover, the lining heals, usually within 2 to 4 weeks if there's no infection on top. If you're getting chemo every 2 or 3 weeks, you may notice a pattern: sore mouth, recovery, next cycle. With high-dose chemo before a stem cell transplant, sores tend to start about 7 to 10 days in and last until counts come back.

How long do radiation mouth sores last?

With head and neck radiation, the mouth usually starts feeling sore and red around the second or third week. Sores build as the dose adds up and are often at their worst in the last couple of weeks of treatment and the week or two after. Most people see real improvement within about 2 to 4 weeks after the last treatment. Larger fields, higher doses, and chemo given along with radiation can make it last longer. Dry mouth and taste changes often hang on well after the sores have healed.

What causes oral mucositis, and who gets it worst

Chemo and radiation target cells that divide quickly. The lining of your mouth renews itself every week or two, so it gets hit too. The treatment sets off inflammation in the tissue under the surface, the top layer thins out and breaks down, and sores form. Bacteria in the mouth then make the open areas more inflamed and painful. It isn't caused by anything you did, and it isn't a sign that treatment is going badly.

Things that raise the risk

  • Radiation to the head and neck, especially when chemo is given at the same time.
  • High-dose chemo before a stem cell transplant (for example, melphalan).
  • Certain chemo drugs, including 5-fluorouracil (5-FU), methotrexate, doxorubicin, and others.
  • Mouth sores from chemo pills. Oral cancer drugs can do it too. Capecitabine turns into 5-FU in the body. Everolimus and some other targeted drugs cause a type of sore (often called stomatitis) that looks more like canker sores, usually in the first weeks.
  • Tooth and gum problems going in, like infected teeth, sharp edges, or gum disease.
  • Smoking, alcohol, and a dry mouth.
  • Kidney problems that slow how the body clears some chemo drugs.

Mucositis vs. stomatitis

You'll see both words. "Stomatitis" means inflammation anywhere in the mouth, from any cause. "Oral mucositis" is the specific kind caused by cancer treatment. Some oncologists use "stomatitis" for the canker-like sores from targeted drugs like everolimus, which behave a little differently and are often treated with a steroid rinse your oncologist prescribes.

Can you get oral mucositis without cancer?

True oral mucositis almost always comes from cancer treatment. A few medicines used for other conditions can cause something similar, most notably methotrexate. Mouth sores from methotrexate are a known warning sign of toxicity, especially if a weekly dose was taken daily by mistake, so call the prescribing doctor that day. One more source of confusion: dentists use "peri-implant mucositis" for gum inflammation around a dental implant. That's a completely different, much milder problem. Other mouth sores without cancer treatment are usually canker sores or one of the causes on our mouth ulcers page.

Oral mucositis symptoms

  • Burning, stinging, or a raw feeling, worse with spicy, salty, acidic, or hot foods
  • Pain when eating, talking, or swallowing, sometimes down into the throat (radiation mouth pain often includes the throat when it's in the field)
  • Red, swollen, or shiny lining, then open sores
  • Thick, stringy saliva, especially with radiation
  • Bleeding from the gums or sores, mainly when platelets are low
  • Trouble wearing dentures
  • Taste changes

Chemo mouth taste and radiation mouth taste

Taste changes are their own side effect, but they often travel with mucositis. During chemo, many people describe a metallic or bitter taste, or food that tastes like nothing. During head and neck radiation, taste often fades in the first few weeks, and dry mouth makes it worse. Taste usually starts coming back in the months after treatment ends, though for some people it doesn't fully return to how it was. Plastic utensils can help with a metallic taste. Tart foods can wake up taste but will sting open sores, so save them for when the mouth has healed.

Mucositis, thrush, or herpes? Infections that look similar

Cancer treatment lowers your defenses, and two common infections can show up on top of mucositis or be mistaken for it. They're worth spotting early because they're treatable with prescription medicine. If something changes suddenly or looks different from what your nurses have been seeing, tell them.

Oral mucositisOral thrush (yeast)Herpes reactivation
What it looks likeRed, raw lining with sores that may have a yellow-white filmWhite or creamy patches that usually wipe off and leave a red, sore spot. Sometimes just redness and burning.Clusters of small sores that run together, often with ragged edges
WhereSoft lining: cheeks, inner lips, sides and underside of the tongue, soft palateTongue, palate, cheeks, corners of the mouthLips, gums, hard palate, and in people with very low counts, anywhere
TimingFollows the chemo cycle or builds through radiationAny time, especially with steroids, antibiotics, or dry mouthCan appear suddenly, sometimes with a cold sore on the lip
Contagious?NoNot usually a concern for healthy family membersYes, the virus can spread by contact
TreatmentMouth care, pain control, timeAntifungal medicine, such as nystatin rinse, clotrimazole troches, or fluconazoleAntiviral medicine, such as acyclovir or valacyclovir (Valtrex)
Learn moreThis pageOral thrushCold sores and oral herpes

Two more possibilities your team may think about: bacterial infections in people with very low white counts, and, in people who have had a stem cell transplant, graft-versus-host disease, which can cause lacy white lines and sores much like oral lichen planus. Some immunotherapy drugs can also cause lichen planus-like patches, dry mouth, or taste changes rather than classic mucositis.

Daily mouth care during chemo and radiation

A simple, steady routine is the one thing every major guideline agrees on. A clean mouth has fewer bacteria irritating the sores and a lower chance of infection. The MASCC/ISOO guidelines support using an organized oral care routine during chemo, head and neck radiation, and stem cell transplants. Here's the basic version we give our patients. Follow your cancer center's instructions if they differ.

  1. Brush gently after meals and at bedtime. Use an extra-soft toothbrush and a mild fluoride toothpaste. Soften the bristles in warm water first. If brushing truly hurts too much, use the softest brush you can for now and get back to it as soon as you can. Foam swabs don't clean teeth well and shouldn't replace brushing for long.
  2. Keep flossing if you already floss and it doesn't cause bleeding. If your platelets are low, ask your oncology team whether to pause.
  3. Rinse often with a bland rinse. Mix about ½ teaspoon salt and ½ teaspoon baking soda in a cup (8 oz) of water. Swish gently and spit. Many people rinse every few hours while awake and after meals. This is the chemo mouth rinse recipe most cancer centers hand out, and it's fine to make fresh each day.
  4. Skip alcohol-based mouthwash. It burns and dries the mouth. If your team wants you to use an antiseptic rinse, they'll tell you which one.
  5. Keep your lips moist with a plain lip balm or lanolin. Ask your radiation team what's OK on your lips before treatment sessions.
  6. Keep dentures clean and out as much as you can. Clean them daily, soak them overnight, and leave them out when your mouth is sore.
  7. Use fluoride every day if you're having head and neck radiation. That usually means fluoride gel in custom trays at bedtime. It protects teeth from the fast decay that radiation-related dry mouth can cause.
  8. Look in your mouth once a day with a flashlight and mirror, and tell your team about new white patches, blisters, or bleeding.

Mouth sores from chemo home remedies: what to skip

  • Hydrogen peroxide for days on end. It can slow healing. Use it only if your team tells you to, and only briefly.
  • Anything that burns: alcohol, lemon, vinegar, cinnamon, or strong mint products.
  • Homemade "magic mouthwash." Don't mix numbing medicines yourself. See below.
  • Supplements and herbal rinses without checking. Some interact with chemo.

Chemo mouth sores treatment: what helps the pain

Pain from oral mucositis is real and can be severe. Treating it isn't a sign of weakness. Good pain control keeps you eating, drinking, and getting through treatment on schedule. Your oncology team decides which medicines are right for you, and they'll adjust as things change.

OptionHow it helpsThings to know
Bland salt and baking soda rinsesKeep sores clean, loosen thick saliva, sootheSafe to use often. Over the counter.
Ice chips or cold waterNumb the mouth for a short timeFine for comfort. Skip cold if you're getting oxaliplatin, which can make cold feel painful.
Over-the-counter numbing gels (benzocaine, lidocaine)Brief relief for a single spot before mealsAsk your team first. Numbing the back of the mouth can affect swallowing. Never use benzocaine in children under 2.
Coating or barrier gels and rinsesForm a film over soresSome are over the counter and some are prescription. Results vary from person to person.
Acetaminophen (Tylenol)General pain reliefCheck your temperature before taking it, because it can hide a fever. Ask your team before using ibuprofen or aspirin, which may not be safe with low platelets.
Prescription rinses (magic mouthwash, doxepin, morphine rinse)Numb or calm the mouthPrescription only. Evidence is mixed. See the next section.
Prescription pain medicine by mouth, patch, or IVSteady control of moderate to severe painCommon with radiation and transplants. Taking it on a schedule, before pain gets bad, works better than chasing it.

Does honey help chemo mouth sores?

Possibly, mostly for radiation. The MASCC/ISOO guidelines list honey as a suggestion for preventing mucositis in people getting head and neck radiation, based on smaller studies where people both coated the mouth with it and swallowed it. It isn't a cure. Check with your oncology team first, especially if you have diabetes or very low white counts, and never give honey to a baby under 1.

Magic mouthwash: what's in it, and does it work?

"Magic mouthwash" isn't one product. It's a name for a family of mouth rinses that a doctor or dentist prescribes and a pharmacy mixes. Hospitals and pharmacies each have their own versions.

What is in magic mouthwash? Most versions combine some of these:

  • a numbing medicine, usually viscous lidocaine
  • an antihistamine, usually diphenhydramine, which also has a mild numbing effect
  • a liquid antacid that helps it coat the mouth
  • sometimes an antifungal (nystatin), a steroid, or other ingredients

Is magic mouthwash over the counter? No. Some of the ingredients can be bought on their own, but the mixed rinse is a prescription, and you shouldn't try to make it yourself. Lidocaine in the wrong strength or amount can numb your throat enough to raise the risk of choking, and swallowing too much can be dangerous, especially for children. That's why we don't share a magic mouthwash recipe here. Your pharmacist will give you exact directions with the prescription.

Does it work? Many people say it takes the edge off for a short while, often before meals. The research is less impressive. In a large U.S. trial of people getting head and neck radiation, a lidocaine-diphenhydramine-antacid rinse and a doxepin rinse each eased pain more than a placebo rinse over 4 hours, but the difference was smaller than researchers consider clinically meaningful. The MASCC/ISOO guidelines don't make a recommendation for or against it. A morphine mouth rinse has a little more support for pain during chemo-radiation and is used at some centers.

Magic mouthwash side effects can include stinging, an odd taste, numbness that makes it hard to feel hot food or tell where food is in your mouth, and drowsiness from the diphenhydramine or doxepin. If it stings more than it helps, tell the prescriber. There are other options.

Eating and drinking with mouth sores

Keeping fluids and calories up matters more than eating perfectly. Weight loss and dehydration can make treatment harder on your body. If eating has become a battle, tell your team early. A dietitian can help, and if mucositis gets severe, your team may talk about a feeding tube for a while. That's a common, temporary bridge, not a failure.

  • Go soft, moist, and cool or room temperature. Yogurt, smoothies without citrus, scrambled eggs, oatmeal, mashed potatoes, soups that aren't hot, pudding, cottage cheese, soft pasta, and protein shakes.
  • Avoid what stings: citrus, tomatoes, vinegar, spicy food, salty snacks, alcohol, carbonation, and crunchy or sharp foods like chips and toast.
  • Add moisture. Gravies, sauces, broth, and butter make food easier to swallow.
  • Use a straw to get liquids past the sore spots.
  • Eat small amounts often instead of three big meals.
  • Time it. If you've been prescribed a numbing rinse or pain medicine, take it so it's working when you eat.
  • Sip all day. Water, milk, and nutrition drinks count. Keep a bottle within reach.

What a dentist can do before, during, and after treatment

Your oncology team manages mucositis. Our job is to get your mouth as ready as it can be before treatment, keep it comfortable during, and protect your teeth for the long run. Dr. Henley is on staff at Baptist Medical Center Jacksonville and works with many head and neck cancer patients and their oncology teams. You can read more on our head and neck cancer dental care page and in our post on cancer and dental health.

Before treatment

  • A pre-treatment dental exam with X-rays to find infected teeth, broken fillings, sharp edges, and gum problems. Ideally this happens a few weeks before treatment starts so there's time to heal if anything needs to be removed. Even a short visit helps.
  • Treat infections and remove teeth that can't be saved before radiation, when healing is more predictable. We coordinate timing with your oncology team so treatment isn't held up.
  • Custom fluoride trays for anyone having radiation that includes the salivary glands or jaws.
  • Smooth sharp teeth and adjust dentures so nothing rubs once the lining gets tender.
  • A plan for bone medicines. If you'll be getting drugs like zoledronic acid or denosumab, it changes how we plan dental work. See bone medications and your dental health.

During treatment

  • Check your mouth, spot thrush or herpes, and let your oncology team know what we see
  • Gentle cleanings when your counts allow, and help with a home care routine you can actually manage
  • Fix a broken tooth or a denture sore spot that's making mucositis worse
  • Comfort care and advice, always coordinated with your oncologist

After treatment

  • Frequent checkups and fluoride for dry mouth and decay prevention
  • Jaw stretching and monitoring for radiation-induced trismus (stiff jaw)
  • Careful planning before any extraction in a jaw that received radiation
  • Regular checks of the mouth lining alongside your oncology follow-up, never in place of it

Our care for medically complex patients page explains how we work with physicians during treatment.

Can oral mucositis be prevented?

Not completely, but the risk and severity can often be lowered. The MASCC/ISOO guidelines, last fully updated in 2020, list several measures that help in specific situations. Your oncology team decides which apply to you. Never change, skip, or delay any part of your cancer treatment because of mouth sores without talking with them first.

  • A good dental checkup before treatment and a daily oral care routine.
  • Oral cryotherapy (ice chips). Holding ice chips in the mouth during certain infusions, such as bolus 5-FU or high-dose melphalan before a transplant, narrows blood vessels in the mouth so less drug reaches the lining. It's only for specific drugs and only when your team says so.
  • Photobiomodulation (low-level light or laser therapy). Recommended to prevent mucositis in stem cell transplants and head and neck radiation. It's offered at some cancer centers, so ask whether yours has it.
  • Palifermin, an IV medicine, for some stem cell transplant regimens.
  • Benzydamine mouth rinse is recommended in the guidelines for some head and neck radiation patients, but it isn't approved or sold in the United States.
  • Honey for head and neck radiation, as above.
  • Radiation planning. Modern techniques spare as much of the mouth as possible. Our article on whether a lower radiation dose protects your mouth after HPV throat cancer looks at recent research.
  • Not smoking or drinking alcohol during treatment.

Chlorhexidine rinse isn't recommended to prevent mucositis during head and neck radiation, though your team may use it for other reasons.

Children, stem cell transplants, and denture wearers

Children. Kids on chemo get mucositis too, and they may not be able to tell you it hurts. Watch for drooling, refusing food or drinks, or fussiness at meals. Keep brushing with a soft brush. Don't use numbing products on a child unless the oncology team prescribes them, and never use benzocaine in children under 2.

Stem cell transplant. High-dose chemo, sometimes with total body radiation, causes some of the most severe mucositis. This usually happens in the hospital, where pain is often managed with an IV pump you control. It heals as the new cells take hold and counts recover.

Leukemia and lymphoma. Low counts make bleeding and infection more likely. Our leukemia and the mouth page covers this in more detail.

Denture wearers. Leave dentures out as much as possible when your mouth is sore, and keep them very clean. After treatment, your mouth may change shape, and a reline or new dentures may be needed.

When to call your oncology team vs. your dentist

When in doubt, call the oncology team first. They know your blood counts and your treatment plan, and they can bring us in.

Make an appointment with your dentist if:

  • You're about to start chemo or head and neck radiation and haven't had a dental exam
  • A sharp tooth, broken filling, or denture is rubbing a sore spot
  • You need fluoride trays, or yours don't fit
  • Your mouth healed after treatment but feels dry, your jaw feels stiff, or a tooth is sensitive
  • A sore is still there weeks after treatment has ended and your oncology team wants it looked at

Get care today from your oncology team if:

  • You have a fever of 100.4°F (38°C) or higher, chills, or feel very unwell
  • You can't eat or drink, can't keep fluids down, or are dizzy or making little urine
  • Pain isn't controlled
  • Bleeding from the mouth won't stop
  • You see new white patches, blisters, or a cold sore, or the sores suddenly get worse
  • You have trouble breathing or swallowing your own saliva

Oral mucositis FAQ

How long do radiation mouth sores last?

Radiation mouth sores usually begin around the second or third week of head and neck radiation and build until the end of treatment. They often peak in the last weeks of treatment and the week or two after. Most people see real healing within about 2 to 4 weeks after the last treatment, though it can take longer with higher doses or chemo given at the same time.

What do chemo mouth sores look like?

Chemo mouth sores start as red, shiny, swollen areas inside the cheeks, lips, or on the sides and underside of the tongue. They can turn into shallow open sores covered with a yellow-white or gray film, and in severe cases the sores merge into large raw patches. White patches that wipe off are more likely thrush, and clusters of small blisters may be herpes, so tell your oncology team about those.

What helps mouth sores from chemo?

Gentle brushing with an extra-soft toothbrush, frequent salt and baking soda rinses, soft and cool foods, and avoiding alcohol mouthwash and acidic or spicy foods all help. Your oncology team can prescribe numbing rinses or stronger pain medicine if you need them. Check with them before using over-the-counter pain relievers, and take your temperature before using acetaminophen because it can hide a fever.

Is magic mouthwash over the counter?

No. Magic mouthwash is a prescription mix that a pharmacy prepares, usually containing a numbing medicine, an antihistamine, and an antacid. Some ingredients are sold on their own, but you shouldn't mix your own version, because the numbing medicine can affect swallowing and be harmful in the wrong amount.

What is in magic mouthwash?

Most versions contain viscous lidocaine (a numbing medicine), diphenhydramine (an antihistamine), and a liquid antacid that helps it coat the mouth. Some also include nystatin, a steroid, or other ingredients. Recipes vary by hospital and pharmacy, and research on how well it works is mixed.

Can you get mucositis without cancer?

True oral mucositis almost always comes from chemotherapy or radiation. A few non-cancer medicines, especially methotrexate, can cause similar sores, and that can be a sign of toxicity that needs a same-day call to the prescriber. Most mouth sores in people who aren't in cancer treatment are canker sores, injuries, or viral sores.

When does mucositis start after chemo?

Mucositis usually starts about 5 to 10 days after a chemo dose. It tends to be worst over the following week, around the time blood counts are lowest. With high-dose chemo before a stem cell transplant, it often starts about 7 to 10 days into treatment.

How long does mucositis last after chemo?

Chemo mucositis usually heals within 2 to 4 weeks as blood counts recover, as long as no infection develops on top of it. If you get chemo in repeated cycles, sores may come back with each cycle. Tell your team if sores aren't healing or are getting worse with each round.

Is oral mucositis contagious?

No. Oral mucositis is a side effect of treatment, not an infection, so you can't pass it to anyone. Herpes sores that sometimes appear during treatment can spread by contact, which is one reason to tell your team about new blisters.

Can I use regular mouthwash during chemo or radiation?

Avoid mouthwashes that contain alcohol, because they sting and dry the mouth. A homemade rinse of about ½ teaspoon salt and ½ teaspoon baking soda in a cup of water is gentle and can be used often. If your team prescribes a specific rinse, use that as directed.

Should I see a dentist before starting chemo or radiation?

Yes, ideally a few weeks before treatment starts. A dental exam can find infected teeth, sharp edges, and gum problems that make mucositis and infections worse, and it allows time to heal if a tooth needs to come out. People getting head and neck radiation also need custom fluoride trays to protect their teeth.

What's the difference between mucositis and stomatitis?

Stomatitis is a general word for inflammation of the mouth from any cause. Oral mucositis is the specific inflammation and sores caused by cancer treatment. Some oncologists use "stomatitis" for the canker-like sores caused by targeted drugs such as everolimus.

Should I stop cancer treatment if my mouth sores are bad?

Don't stop or delay anything on your own. Call your oncology team and tell them exactly how bad the pain is and how much you're able to eat and drink. They have many ways to help, from stronger pain control to IV fluids and nutrition support, and only they can decide whether any change to treatment makes sense.

Getting ready for cancer treatment?

If you're in the Jacksonville area and about to start chemo or head and neck radiation, or you're in the middle of it and your mouth needs help, we'd be glad to see you. We'll check your teeth, make fluoride trays if you need them, and work directly with your oncology team.

Related conditions

Sources

  1. Elad S, Cheng KKF, Lalla RV, et al. MASCC/ISOO clinical practice guidelines for the management of mucositis secondary to cancer therapy. Cancer. 2020;126(19):4423–4431.
  2. Hong CHL, Gueiros LA, Fulton JS, et al. Systematic review of basic oral care for the management of oral mucositis in cancer patients and clinical practice guidelines. Support Care Cancer. 2019;27(10):3949–3967.
  3. Saunders DP, Rouleau T, Cheng K, et al. Systematic review of antimicrobials, mucosal coating agents, anesthetics, and analgesics for the management of oral mucositis in cancer patients and clinical practice guidelines. Support Care Cancer. 2020;28(5):2473–2484.
  4. Sio TT, Le-Rademacher JG, Leenstra JL, et al. Effect of doxepin mouthwash or diphenhydramine-lidocaine-antacid mouthwash vs placebo on radiotherapy-related oral mucositis pain: the Alliance A221304 randomized clinical trial. JAMA. 2019;321(15):1481–1490.
  5. Raber-Durlacher JE, Zadik Y, Treister NS, et al. MASCC/ISOO clinical practice statement: current understanding on controversies in basic oral care in hemato-oncology and hematopoietic cell transplantation. Support Care Cancer. 2024;32(8):550.
  6. National Cancer Institute. Oral Complications of Cancer Therapies (PDQ), Patient Version.

This page is for general education and isn't a diagnosis. Every mouth is different. If you have a sore you're worried about, see your dentist or physician. Photos marked Wikimedia Commons are used under their listed licenses and may have been cropped or resized.