Related Terms

  • Acquired immune deficiency syndrome, acquired immunodeficiency syndrome, acrodermatitis enteropathica, AIDS, AIDS-defining illness, antifungal, aphthous stomatitis, aphthous ulcers, Candida albicans, canker sores, celiac disease, celiac sprue, chemotherapy, cold sores, fever blisters, fungal infection, fungal spores, fungi, fungus, gastroesophageal reflux disease, GERD, hairy leukoplakia, herpes simplex, herpes simplex virus, herpes virus, HIV, human immunodeficiency virus, immune, immune defense system, immune system, immunocompromised, immunodeficiency, infection, inflammation, leukoplakia, mucositis, opportunistic infection, oral candidiasis, oral herpes, oral mucositis, oral thrush, radiation mucositis, radiation-induced mucositis, throat culture, thrush, zinc, zinc deficiency.


  • Mouth ulcers are open lesions or sores in the mouth that can be caused by many different disorders or conditions, such as viral or fungal infections, immune deficiency, or cancer. Types of mouth ulcers include acrodermatitis enteropathica, canker sores, cold sores, oral leukoplakia, oral candidiasis (oral thrush), and oral mucositis.
  • Acrodermatitis enteropathica is a medical condition in which the body is unable to absorb zinc.
  • Canker sores are common but mostly harmless, and they appear inside the mouth as white or gray ulcers, which are eroded areas of the oral cavity that are marked by tissue disintegration, with a red border. A small percentage of patients may develop severe canker sores (complex aphthosis), which are persistent and painful sores. In infants, painful sores may interfere with eating and may require a visit to the pediatrician. In patients with a weakened immune system (for example, patients who are HIV positive or receiving chemotherapy), the fungus may spread throughout the body, causing infection in the esophagus (esophagitis), brain (meningitis), heart (endocarditis), joints (arthritis), or eyes (endophthalmitis).
  • Cold sores, or herpes labialis, is a condition that involves sores on the lips and inflammation of the gums and mouth. It is caused by the herpes simplex virus type 1 (HSV-1).
  • Oral leukoplakia is a condition in which thickened, white patches form on the gums, on the inside of the cheeks, and sometimes on the tongue. The cause of leukoplakia is unknown, but it is considered to result from chronic irritation. A subtype of leukoplakia is oral hairy leukoplakia (OHL). Hairy leukoplakia of the mouth is an unusual form of leukoplakia that is seen only in people who are infected with the human immunodeficiency virus (HIV) or have acquired immunodeficiency syndrome (AIDS) or AIDS-related complex.
  • Oral thrush is a fungal or yeast infection in the mouth caused by an overgrowth of the fungus Candida albicans.
  • Oral mucositis is an inflammation of mucous membranes of the mouth, and it has been reported in many patients receiving radiation therapy.
  • Symptoms of mouth ulcers include pain and redness at the site of the lesion. Diagnosis is usually performed by examination of the appearance of the lesion or further tests, such as a blood test or biopsy. Treatment involves oral hygiene, topical preparations, and avoidance of irritating substances on or near the lesion.

Risk Factors

  • Canker sores:
    The American Dental Association (ADA) has identified fatigue, stress, and allergies as potentially increasing the chances of getting a canker sore. Similarly, patients with lowered immune systems or intestinal problems, such as ulcerative colitis and Crohn’s disease, may be more susceptible to developing canker sores.
  • Celiac disease: Celiac disease, also called celiac sprue, is a digestive disorder that occurs when an individual’s immune system overreacts to the protein gluten or other proteins within gluten (such as gliadin) found in grains, including wheat, rye, barley, and, to some degree, oats. When a patient with the disease eats food that contains gluten, the immune system’s response damages the intestinal lining. This causes symptoms of abdominal pain and bloating. Additionally, complications, including poor absorption, may occur if the patient continues to eat gluten-containing foods. When the intestinal lining is damaged, patients have difficulty absorbing nutrients.
  • It has not been determined what triggers this reaction in celiac patients. However, celiac disease is associated with autoimmune disorders, such as lupus. Autoimmune disorders occur when the patient’s immune system mistakenly identifies body cells as harmful invaders, such as bacteria. As a result, the immune cells in celiac patients attack the patient’s own intestinal cells.
  • Researchers at the National Digestive Diseases Information Clearinghouse (NDDIC) estimate that one out of 133 people in the United States have celiac disease. The prevalence is even higher (one out of 22 people) among patients who have immediate family members (a parent or sibling) who have the disease. This suggests that the disease may be inherited (passed down through families) in some cases. Individuals can develop the disease at any age, but it is most commonly diagnosed in patients who are 8-12 months old or 30-40 years old.
  • Although there is currently no cure for celiac disease, the condition can be managed with a gluten-free diet. In general, patients who strictly follow a gluten-free diet can expect to live normal, healthy lives. Symptoms will subside in several weeks, and patients will be able to absorb food normally once they avoid eating gluten. A dietician or certified nutritionist may help a patient with celiac disease develop a healthy diet. Patients with celiac disease may also find gluten-free cookbooks to be a helpful resource. Many products, including rice flour and potato flour, can be used as substitutes for gluten.
  • Cold sores (herpes simplex virus): Everyone is at risk for HSV-1 (herpes labialis or oral herpes). It is easily transmitted and is the most common form of the herpes simplex virus. According to the American Social Health Association, about 50-80% of adults in the United States have oral herpes.
  • HSV-1 can be spread by close contact with someone who has a cold sore or by using items contaminated with the virus. Kissing someone on the mouth will spread the virus, and sharing personal items such as razors, towels, or eating utensils with a person who has oral herpes will increase the risk of getting HSV-1. The virus can also be spread to the genital area of another individual through oral sex. Healthcare practitioners suggest that individuals with oral herpes not perform oral sex on their partners. They should also avoid kissing during outbreaks. Infants and young children (up to three years old) have an increased risk of being exposed to HSV-1 due to immune systems that are still not fully developed.
  • Gastroesophageal reflux disease (GERD): Gastroesophageal reflux disease (GERD), also called acid reflux disease, occurs when liquid from the stomach regurgitates (backs up) into the esophagus. This liquid may contain stomach acids and bile. In some cases, the regurgitated stomach liquid can cause inflammation (esophagitis), irritation, and damage to the esophagus.
  • It remains unknown exactly what causes GERD. Several factors, including hiatal hernias (when the stomach pushes up through a hole in the diaphragm muscle), abnormally weak contractions of the lower esophageal sphincter, and abnormal emptying of the stomach after a meal, have been associated with GERD.
  • Common symptoms of GERD include a burning sensation in the chest that may spread to the throat (heartburn), chest pain (especially when lying down), dysphagia (difficulty swallowing), regurgitating food or sour liquid, coughing, hoarseness, sore throat, and wheezing.
  • Several factors may worsen symptoms of the condition. For instance, spicy foods, fatty foods, chocolate, caffeine, tomato sauce, carbonated beverages, mint, alcoholic beverages, large meals, lying down after eating, some medications (e.g., sedatives, tranquilizers, or blood pressure drugs), and cigarette smoking may worsen symptoms of GERD.
  • GERD is usually a lifelong condition, because there is no cure for the disorder. Patients must take medications for the rest of their lives to manage the symptoms. In addition, patients should not smoke, because it may increase the amount of stomach acid and worsen symptoms.
  • Leukoplakia:
    Although anyone can develop leukoplakia, it is most common in older men. The American Dental Association (ADA) suggests that tobacco use appears to be responsible for most cases of leukoplakia, although other risk factors may include ill-fitting dentures or cheek biting.
  • Mucositis: Oral mucositis is a frequent complication of anticancer treatment. Its incidence varies, depending on the patient and treatments themselves. In a review article, Volpato et al. reported that patients with cancers of the blood, such as leukemia and lymphoma, tend to show a 2-3 times higher rate of oral complications than patients with solid tumors. Similarly, young patients (less than 12 years of age) may be more susceptible to chemotherapy-induced oral adverse effects. Certain chemotherapy agents are more likely to cause this side effect, such as cytarabine (Cytosar-U®), doxorubicin (Adriamycin®), and methotrexate (Rheumatrex®). Most patients receiving radiotherapy in the head and neck develop some degree of mucositis. It has been reported that mucositis almost always occurs in patients receiving a combination of chemotherapy and radiotherapy.
  • Factors that may increase the risk of developing mucositis include poor oral or dental health, smoking, chewing tobacco products, drinking alcohol, dehydration, and diseases such as kidney disease, diabetes, or HIV/AIDS. These risk factors may also worsen the condition once it has developed.
  • Oral candidiasis (oral thrush): Candida albicans is normally present in a person’s mouth. According to the American Dental Association (ADA), oral thrush commonly occurs in patients who are very young, the elderly, and those with diseases such as diabetes or leukemia or those with weakened immune systems, such as HIV patients. People with xerostomia (dry mouth syndrome) are also more likely to suffer from candidiasis. Use of oral antibiotics, especially broad-spectrum antibiotics, such as levofloxacin or tetracycline, with activity against a wide range of disease-causing bacteria may decrease normal bacteria in the mouth and cause Candida to flourish, resulting in candidal infections.


  • Acrodermatitis enteropathica: The exact cause of acrodermatitis enteropathica (an inborn error of zinc metabolism) remains unclear and continues to be debated. However, researchers believe that genetics may play a role and this condition and that it may be an inherited autosomal recessive disorder. An autosomal chromosome is a non-sex chromosome. Differences in the prevalence of the condition among races have yet to be reported.
  • Canker sores:
    The reason canker sores appear is unknown, but some experts believe that problems with the immune system may be involved. The immune system is the body system that fights disease, bacteria, and viruses. Since canker sores tend to run in families, genetics has been suggested as playing a role in the recurrence of the condition. The American Dental Association (ADA) suggests that fatigue, emotional stress, an accidental bite on the inside of the mouth, a viral infection, an allergic reaction to food, a visit to the dentist, or menstruation may all increase the possibility of developing a canker sore in susceptible patients.
  • Cold sores (herpes simplex virus): Cold sores are caused by a reactivation of the herpes simplex-1 virus after a period of latency or inactivity, in which a trigger suddenly causes the virus to replicate, resulting in a herpes outbreak. Exposure to sunlight or other ultraviolet light, such as black lights or fluorescent lamps, is a common trigger for the formation of cold sores. Stress on the body due to illness or excessive exercise can weaken the body’s immune system and lead to an outbreak of oral herpes. Common examples of stress or illness include infection, fever, a cold, physical injury, dental surgery, menstruation, medications (including steroids), illnesses (such as the human immunodeficiency virus (HIV)) that suppress the immune system, eczema, excessive exercise, and emotional stress.
  • Leukoplakia: Leukoplakia is a condition in which white patches form on the gum, the exact cause of which is unknown. Tobacco use appears to be responsible for most cases of leukoplakia. The majority of individuals who develop leukoplakia are smokers, and most leukoplakic patches either improve or disappear within a year after stopping smoking. Chewing tobacco and snuff also play a key role. As many as three out of four regular users of smokeless tobacco products eventually develop leukoplakia where they hold the tobacco against their cheeks. Dentifrices containing sanguinarine (a compound found in the herb bloodroot) have been associated with leukoplakia in patients using tobacco products. Other possible causes have been linked to leukoplakia, including long-term alcohol use; chemotherapy or radiation treatments to the head and neck; Candida albicans (which causes oral thrush); the human papillomavirus (HPV, responsible for genital warts); irritation from rough teeth, fillings, or ill-fitting dentures; and sun exposure to the lips.
  • Mucositis: Oral mucositis occurs as a result of both direct toxicity on the mucosal cells and myelosuppression, a condition in which bone marrow activity is decreased from chemotherapy and radiotherapy, resulting in fewer red blood cells, white blood cells, and platelets. The lining of the gastrointestinal tract (from the mouth to the anus) is made of epithelial cells, which normally divide and replicate rapidly. Chemotherapy and radiation treatments not only kill cancer cells but also damage epithelial cells, preventing them from regenerating. This damage results in the painful sores characteristic of mucositis.
  • Oral candidiasis (oral thrush): Candidiasis is an opportunistic infection caused by the fungus Candida albicans. Opportunistic infections occur in individuals who have weakened immune systems. The Candida albicans fungus is found almost everywhere in the environment, which is why most people have small amounts of Candida albicans in their mouths at any given time. Some common causes of oral thrush include xerostomia (dry mouth) and the use of antibiotics and immunosuppressants, which are any substances that lower the body’s immune response.

Signs and Symptoms

  • Acrodermatitis enteropathica: In infants, the symptoms of acrodermatitis enteropathica generally appear as red and swollen patches of dry and scaly skin with crusted or pus-filled blisters around the face, the buttocks, and the extremities. Infants also tend to have mouth ulcers, a red and glossy (wet and shiny) tongue, diarrhea, behavioral changes, and neurologic disturbances. In older children, the most typical symptoms include failure to grow, anorexia (decreased appetite), swollen skin around the nails, and repeated infections. Additional common symptoms include pinkeye, hair loss (eyelashes, eyebrows, and on the scalp), sensitivity to light, irritability, and depressed mood.
  • Canker sores: Canker sores appear inside the mouth as ulcers (eroded areas of the oral cavity, marked by tissue disintegration) that are white or gray with a red border. These sores usually develop on the inside of the lips, the cheeks, or the tongue. The lesions usually heal in 7-14 days and tend to recur. In most cases, fever is not present. The sores can cause sharp pain in the mouth, affecting the patient’s ability to eat, drink, or speak.
  • Cold sores (herpes simplex virus): The symptoms of cold sores are blisters on or around the lips and the edge of the mouth. The first symptoms usually appear within one or two weeks and as late as three weeks after contact with an infected person. In certain people, the virus may stay dormant or inactive for years or may never cause an outbreak at all.
  • The first symptom that may appear during an outbreak of oral herpes or cold sores may include tingling, burning, or itching in the area around the mouth or nose. This first portion of the outbreak is known as the prodrome stage (or period).
  • Within a few hours to days, the area may become reddened and develop small, fluid-filled blisters called vesicles. Several of these small blisters may even come together and form one large blister. Cold sore blisters usually break open, weep clear fluid, and then crust over and disappear after a few days.
  • The patient may experience symptoms including a sore mouth that makes eating, drinking, and sleeping uncomfortable. Other symptoms include fever, sore throat, and swollen lymph nodes in the neck.
  • Symptoms usually last 7-10 days. Following the active infection, the virus becomes latent (dormant), residing in the nerve cells, and may reactivate later, causing a new outbreak at or near the original site.
  • Leukoplakia: Leukoplakia can have various appearances, but it typically first appears as flat, gray or gray-white plaques (sores), usually on the gums or on the insides of the cheeks and sometimes on the tongue. Over weeks or months, leukoplakia can develop into patches with a white color; a thick, rough, or wrinkled texture; and a hardened surface. Sometimes, individuals may also have erythroplakia (raised red lesions or sores, which are more likely to show precancerous changes).
  • Mucositis: Radiation and chemotherapy may damage the lining of the mouth, resulting in symptoms ranging from slight soreness to mouth ulcers. The sores may appear on any of the soft tissues of the lips or mouth, including the gums and tongue. Other symptoms include a red, shiny, or swollen mouth and gums, blood in the mouth, soreness or pain in the mouth or throat, difficulty swallowing or talking, a feeling of dryness or pain when eating food, and increased or thicker saliva in the mouth.
  • Mucositis due to radiation usually appears toward the end of the second week of treatment, plateaus during the fourth week of radiation, and may persist for 2-3 weeks after treatment is over.
  • Mucositis due to chemotherapy typically begins 3-5 days after the start of therapy, peaks at 7-10 days, and slowly subsides over the next week.
  • Oral candidiasis (oral thrush): Symptoms of oral thrush may develop suddenly. Oral thrush symptoms are usually easy to spot and include white or yellow spots in the mouth, particularly on the tongue and the inside of the cheeks; raised areas in the mouth that bleed and become sore if scraped; a burning sensation in the throat; and difficulty chewing and swallowing.


  • The American Dental Association (ADA) recommends visiting a dentist if a mouth sore lasts a week or longer.
  • Acrodermatitis enteropathica: A zinc deficiency can be diagnosed from a blood test. Characteristic symptoms such as dermatitis (skin inflammation), hair loss, irritability, and depression may also assist the physician in diagnosing acrodermatitis enteropathica.
  • Canker sores: Canker sore lesions are unique and usually allow for a diagnosis simply on physical examination, however, a complete medical history of the individual may be needed.
  • In addition, a doctor or dentist may order the following tests to help confirm the diagnosis and rule out other causes for the ulcers: blood tests; cultures of the lesions to determine if a virus or bacteria are present; and a biopsy of the lesion. A biopsy is the taking of a small piece of tissue from the lesion and examining it microscopically.
  • Patients with complex aphthosis (constantly having more than three sores) tend to have intestinal or blood diseases, or deficiencies in iron, folic acid, vitamin B6, vitamin B12, or zinc. These patients receive a thorough medical examination and may be referred to a specialist if needed.
  • Cold sores (herpes simplex virus):
    Herpes simplex sores may look like canker sores, but usually a dentist or doctor can diagnose canker sores by their shape and size. Cold sores generally appear around edge of the mouth and on the roof of the mouth, while canker sores develop on the soft tissue of the mouth, for example, the inside of the lips or the tongue. Cold sores also cause a lot of pain for a sore that is quite small. A doctor may test for low levels of folic acid or vitamin B12 in the blood if the sores keep returning. Less commonly, a viral culture test (swabbing the sore in order to culture the virus in a lab) or polymerase chain reaction test (which detects herpes DNA) can be used to assist in diagnosis. The viral culture must be performed within the first 48 hours and before the blister has crusted over.
  • Leukoplakia: Most often, a dentist diagnoses leukoplakia by examining the patches in the mouth and ruling out other possible causes for the symptoms. To help ensure that no early signs of cancer exist, a dentist may biopsy (remove) a tissue sample for analysis. The tissue is then analyzed in a laboratory using a highly specialized imaging system that allows a pathologist to detect a single abnormal cell among hundreds of thousands of healthy cells. A negative report means no abnormal cells are present. If the report is positive, a dentist is likely to perform another biopsy of a small tissue sample and send it to a laboratory for further analysis.
  • Mucositis: Diagnosis of mucositis is based on the exhibited symptoms and appearance of the tissues of the mouth following chemotherapy, bone marrow transplants, or radiotherapy. The appearance will be characterized by red burn-like sores or ulcers throughout the mouth.
  • Oral candidiasis (oral thrush):
    In most cases, diagnoses of candidiasis infections can be determined after a physical examination of the sores, based on their physical appearance and location. If a diagnosis is uncertain, the physician may scrape surface cells of the mouth, or culture a tissue sample from the throat to determine whether the fungus is present. If Candida albicans is present, a positive diagnosis for candidiasis is made.


  • Acrodermatitis enteropathica: Without treatment, acrodermatitis enteropathica will lead to death. Supplementation with zinc ensures complete remission.
  • Canker sores: Canker sores are vulnerable to infection by bacteria in the mouth. Complications of canker sores may include fever, swollen glands, and fatigue. Sores that keep coming back can indicate that important vitamins may be low, especially folic acid or vitamin B12.
  • The American Academy of Family Physicians (AAFP) recommends that patients should contact their physicians when canker sores are large (greater than one centimeter), last longer than a week, or too painful to allow eating.
  • Cold sores (herpes simplex virus): The herpes virus may spread from one area to another on the same person, which is called autoinoculation and most frequently occurs at the time of primary infection. An example of autoinoculation is ocular herpes, which may lead to serious damage of the eye if left untreated.
  • In patients who have a compromised immune system, the cold sores may spread to other parts of the face or may infect organs. Less commonly, the virus may cause encephalitis (acute inflammation of the brain), requiring hospitalization and the use of intravenous medications.
  • Finally, some patients may develop erythema nodosum following a herpes episode. Erythema nodosum is an inflammatory condition in which tender, red nodules form under the skin. Patients suffering from this condition will develop red and painful skin lumps on the front of the legs. Although self-limited (terminating naturally), treatment of the herpes outbreak with antiviral medications may hasten the resolution of erythema nodosum.
  • Leukoplakia: Leukoplakia usually does not cause permanent damage to tissues in the mouth and frequently goes away once the irritating factors, such as smoking, are removed. Some patches may become inflamed, however, causing ongoing discomfort.
  • Oral cancer is the most advanced stage of leukoplakia. Oral cancer most often occurs in people older than the age of 40. It is often found at late stages, when it is harder to treat. This is because oral cancer is not usually painful, so individuals may not recognize the problem early. Also, many people do not visit their dentists often enough to find the cancer early. The most common sites of oral cancer are on the tongue, lips, and floor of the mouth.
  • Hairy leukoplakia, in contrast, is not painful and is not likely to lead to cancer but may indicate the presence of HIV infection or AIDS.
  • Mucositis: The consequences of mucositis can be mild (needing little treatment) to severe (possibly resulting in fatal complications). Severe complications of mucositis include hypovolemia (decreased blood volume), electrolyte abnormalities (such as sodium and potassium imbalances), and malnutrition. Other complications from mucositis may include taste loss, nausea, pain, vomiting, diarrhea, and a sore or dry mouth. These factors may make eating difficult. Weight loss may also occur.
  • Oral candidiasis (oral thrush):
    If left untreated, oral candidiasis may progress to esophageal candidiasis, which occurs when the infection spreads to the esophagus, the tube that leads from the mouth to the stomach. Drugs that suppress acid production, such as H2 blockers and proton pump inhibitors, may contribute to fungal infections of the upper gastrointestinal tract and may predispose some patients to infectious Candida esophagitis.


  • Acrodermatitis enteropathica: Although there is no known cure for acrodermatitis enteropathica, zinc supplements taken by mouth daily have been shown to effectively manage symptoms. The zinc supplementation must be maintained for life. Skin lesions or sores usually heal 1-2 weeks after treatment is started, while other symptoms begin to improve within 24 hours.
  • Along with zinc supplementation, warm compresses and petrolatum applied to the weeping and crusting lesions may promote healing of the skin and alleviate symptoms.
  • Canker sore: Canker sores tend to heal by themselves in 7-10 days. If an individual gets a large sore (larger than one centimeter) or if the sore is present longer than two weeks, it may need to be treated by a healthcare practitioner.
  • Currently, there is no known permanent cure for canker sores. Therefore, treatments are aimed at relieving the pain or discomfort of the sores. Patients can rinse their mouths with salt water, which has antibacterial properties and may aid in healing the canker sore. Avoiding hot and spicy foods also helps to minimize the pain.
  • Pain relievers used for canker sores include viscous lidocaine (Xylocaine viscous®), an anesthetic (an agent that causes partial or complete loss of sensation) that can be applied to the sore or used to rinse the mouth to numb the pain. However, although it relieves pain, it may interfere with an individual’s sense of taste.
  • Applying benzocaine (Orabase® cream, gel, paste, or liquid protectant, or Zilactin® gel or liquid) directly on the sore may keep the sores from becoming irritated by eating, drinking, or brushing the teeth.
  • Benzydamine mouthwash (Difflam®) may provide temporary relief from the pain of canker sores, but it does not speed up healing.
  • The American Academy of Family Physicians recommends mixing equal amounts of Milk of Magnesia® and Benadryl Allergy liquid® (diphenhydramine); a teaspoonful of the mixture can then be swished in the mouth for a minute every 4-6 hours to alleviate pain. This mixture should not be swallowed.
  • Application of a silver nitrate stick will cauterize (sear, deaden) the sore and relieve pain.
  • Severe canker sores may be treated with corticosteroid medications, such as dexamethasone (Decadron®) in a mouth rinse or prednisone (Deltasone®) taken as tablets. A doctor may give those with chronic (long-term) problems with canker sores vitamin B12, iron, or folate for nutrient deficiencies.
  • Cold sores (herpes simplex virus): Cold sores are generally self-limiting. During an outbreak, symptomatic relief may be obtained by keeping the area clean and dry, or by taking pain relievers (such as aspirin, acetaminophen, or ibuprofen).
  • Although a cure is not yet available, antiviral treatments exist. Medications that are taken orally to treat oral herpes include the antiviral medications acyclovir (Zovirax®), valacyclovir (Valtrex®), and famciclovir (Famvir®).
  • There are two antiviral medications that are applied to the skin and prescribed for the treatment of the oral herpes simplex virus (HSV): topical acyclovir ointment (Zovirax®) and penciclovir cream (Denavir®). Both of these drugs work to speed up the healing process and reduce viral activity. These drugs are put directly on the lesions themselves but can also be used at the onset of prodromal symptoms (early symptoms of itching and burning lasting 1-2 days).
  • Other topical treatments for oral herpes are available over the counter (OTC) but are not antiviral compounds like acyclovir and penciclovir. Some also contain anesthetic ingredients (such as lidocaine or benzocaine) that numb the area and induce temporary relief from the discomfort of an outbreak. Unfortunately, some OTC treatments may actually delay the healing time of symptoms, because they can further irritate the area with repeated applications. There is only one U.S. Food and Drug Administration (FDA)-approved cream, docosanol (Abreva®), the only OTC drug that has been clinically proven to help speed the healing process.
  • Leukoplakia: The usual treatment for leukoplakia is to remove the source of the irritation. For most people, quitting smoking or eliminating alcohol consumption clears the condition. When this is not effective or if the lesions show early signs of cancer, a dentist may choose to remove leukoplakic patches using a scalpel, a laser, or a cryoprobe (an extremely cold probe that freezes and destroys cancer cells). These procedures are performed using anesthetics to numb any pain or discomfort. Recurrences of leukoplakia are frequent, so healthcare professionals recommend yearly dental checkups.
  • Oral candidiasis (oral thrush): It is essential to get treatment for thrush if there are any signs of the illness, such as white patches on the tongue. Oral thrush can persist for months, becoming extremely painful. A healthcare provider can prescribe medicated treatments to help restore the balance of yeast in the body. Prescription treatment generally involves taking a course of oral antifungal tablets, such as fluconazole (Diflucan®). Other drugs include nystatin (Nystatin® oral suspension), amphotericin (Fungilin® lozenges), or miconazole (Daktarin® oral gel).
  • Some antifungal medications that are taken by mouth may cause liver damage. This is because they are strong medications that must be broken down by the liver before they can be absorbed into the body. Ketoconazole (Nizoral®) and amphotericin B (Fungizone®, Abelcet®, AmBisome®, or Amphotec®) are those most likely to cause liver damage. Therefore, healthcare professionals recommend that blood tests should be performed regularly during treatment to monitor liver function. Patients who experience nausea, vomiting, weakness, fatigue, abdominal pain (especially near the liver), dark urine, or jaundice (yellowing of the skin and eyes) should consult their healthcare providers immediately. These are all signs of liver damage.
  • Mucositis: Treatment of mucositis is mainly supportive, helping to alleviate redness and pain. Oral hygiene is the mainstay of treatment; individuals are encouraged to clean their mouths every four hours and at bedtime, more often if the mucositis becomes worse.
  • Water-soluble jellies may be used to lubricate the mouth. Salt mouthwash may soothe the pain and keep food particles clear so as to avoid infection.
  • Individuals are also encouraged to drink plenty of liquids, at least three liters daily, and avoid alcohol. Citrus fruits, alcohol, and foods that are spicy are all known to aggravate mucositis lesions.
  • Healthcare professionals recommend that the mouth should be gently rinsed before and after meals and at bedtime with one of the following solutions: one teaspoon of baking soda and two cups of water, or one teaspoon of salt plus one teaspoon of baking soda plus one quart of water. Additionally, Maalox® or Milk of Magnesia® may be applied onto the sore area of the mouth with a cotton swab. Vaseline® may also be used to keep the lips moist. In addition, mouth sores may be coated with Anbesol®, an over-the-counter medication, before meals to numb them during eating.
  • Medicinal mouthwashes such as chlorhexidine (Peridex®) and viscous lidocaine (Xylocaine viscous®) may be used for the relief of pain. Symptomatic pain relief may also be provided by barrier protection agents such as Gelclair®. This viscous oral gel can be diluted and used as an oral rinse. The film-forming agents within Gelclair® coat the oral mucosa, shielding ulcerated tissues and protecting exposed nerve endings.
  • Palifermin (Kepivance®) is a human keratinocyte growth factor (KGF) that has been shown to enhance epithelial cell proliferation, differentiation, and migration.
  • Experimental therapies have been reported, including the use of cytokines and other modifiers of inflammation (such as interleukin-1 and tissue growth factor-beta3), amino acid supplementation (such as glutamine), vitamins (vitamins A, C, and E), colony-stimulating factors, cryotherapy (freezing), and laser therapy.

Integrative Therapies


Good scientific evidence

  • Iodine
    : There is limited research to suggest that iodine mouth rinses may decrease the severity of mucositis in the mouth related to cancer chemotherapy or radiation therapy. Healthcare professionals recommend that the management of mucositis should be discussed with a cancer care team. For chemotherapy mucositis prevention, povidone-iodine rinses have been used up to four times daily.

  • Reactions to iodine may be severe, and deaths have occurred with exposure to iodine. Avoid iodine-based products if allergic or hypersensitive to iodine. Do no use for more than 14 days. Avoid Lugol’s solution and saturated solution of potassium iodide (SSKI, PIMA) with hyperkalemia (high amounts of potassium in the blood), pulmonary edema (fluid in the lungs), bronchitis, or tuberculosis. Use cautiously when applying to the skin, because it may irritate or burn tissues. Use sodium iodide cautiously with kidney failure. Avoid sodium iodide with gastrointestinal obstruction. Iodine is safe in recommended doses for pregnant or breastfeeding women. Avoid povidone-iodine for perianal preparation during delivery or postpartum antisepsis.
  • Lemon balm
    Creams and teas containing lemon balm have been applied on the skin to treat herpes. Rigorous clinical data are lacking. Preliminary clinical studies have demonstrated promising effects.

  • Based on available research, lemon balm taken by mouth has been reported to be relatively well tolerated when taken for up to eight weeks. Minimal side effects have been noted after up to 10 days of application of a lemon balm cream. Avoid if allergic or hypersensitive to lemon balm. Avoid with Graves’ disease (an overactive thyroid gland) or thyroid hormone replacement therapy. Use cautiously with glaucoma, because lemon balm may increase eye pressure. Use caution when operating heavy machinery. Lemon balm preparations may contain trace amounts of lead. Avoid if pregnant or breastfeeding.
  • Zinc
    : Low-quality studies have been conducted to assess the effects of zinc (applied to the skin or taken by mouth) on herpes type 1 or 2. Several of these studies used combination treatments or permitted the continued use of other medications, so the exact role of zinc in those studies is unclear. However, the positive results obtained in most trials suggest that zinc may be a safe and effective alternative treatment for herpes type 1 and 2, and this should encourage further research into the topic using well-designed studies.

  • Zinc is generally considered safe when taken at recommended dosages. Avoid zinc chloride, since studies have not been done on its safety or effectiveness. Avoid with kidney disease. Use cautiously if pregnant or breastfeeding.


Unclear or conflicting scientific evidence

  • Aloe
    : There is weak evidence that treatment of recurrent canker sores of the mouth with aloe gel may reduce pain and increase the amount of time between the appearance of new ulcers. Further research is needed before a conclusion can be made.

  • Avoid if allergic to aloe or other plants of the Liliaceae family (garlic, onions, tulips). Avoid injecting aloe. Avoid applying to open surgical wounds or pressure ulcers. Avoid taking by mouth with diarrhea, bowel blockage, intestinal diseases, bloody stools, hepatitis, arrhythmia (a history of irregular heartbeat), electrolyte imbalances, diabetes, heart disease, or kidney disease. Avoid taking by mouth if pregnant or breastfeeding.
  • Astragalus
    : Some studies suggest that astragalus may inhibit herpes viruses. Additional research is needed in this area.

  • Avoid if allergic to astragalus, peas, or any related plants or with a history of Quillaja bark-induced asthma. Avoid with aspirin or aspirin products or herbs or supplements with similar effects. Avoid with inflammation (swelling) or fever, stroke, transplant, or autoimmune diseases (like HIV/AIDS). Stop use two weeks before surgery or dental or diagnostic procedures with a risk of bleeding, and avoid use immediately after these procedures. Use cautiously with bleeding disorders, diabetes, high blood pressure, lipid disorders, or kidney disorders. Avoid if pregnant or breastfeeding.
  • Beta-carotene
    : Taking beta-carotene orally seems to induce remission (a state when the disease disappears) in patients with oral leukoplakia. Further research is needed to confirm these results.

  • Avoid if sensitive to beta-carotene, vitamin A, or any other ingredients in beta-carotene products.
  • Black tea
    : Early studies report that black tea may lead to clinical improvement in oral leukoplakia and may prevent oral carcinoma. Further research is needed to confirm these results.

  • Avoid if allergic or hypersensitive to caffeine or tannins. Skin rash and hives have been reported with caffeine ingestion. Use caution with diabetes. Use caution if pregnant. Heavy caffeine intake during pregnancy may increase the risk of sudden infant death syndrome (SIDS). Very high doses of caffeine have been linked with birth defects. Caffeine is transferred into breast milk. Caffeine ingestion by infants can lead to sleep disturbances or insomnia. Infants nursing from mothers consuming greater than 500 milligrams of caffeine daily have been reported to experience tremors and heart rhythm abnormalities. Tea consumption by infants has been linked to anemia, decreased iron metabolism, and irritability.
  • Chamomile
    : Poor-quality studies have used chamomile mouthwash for the prevention or treatment of oral mucositis caused by radiation therapy or cancer chemotherapy. Results are conflicting, and it remains unclear if chamomile is helpful for this use.

  • Avoid if allergic to chamomile. Anaphylaxis (serious or life-threatening allergic reaction), throat swelling, skin allergic reactions, and shortness of breath have been reported. Chamomile eyewash may cause allergic conjunctivitis (pinkeye). Stop use two weeks before surgery or dental or diagnostic procedures with a bleeding risk, and do not use immediately after these procedures. Use cautiously if driving or operating machinery. Avoid if pregnant or breastfeeding.
  • Chlorophyll
    : Chlorophyll may treat herpes simplex and herpes zoster, although more research is needed in this area.

  • Avoid if allergic or hypersensitive to chlorophyll or any of its metabolites. Use cautiously with photosensitivity, compromised liver function, diabetes, or gastrointestinal conditions or obstructions. Use cautiously if taking immunosuppressant or antidiabetic agents. Avoid if pregnant or breastfeeding.
  • Honey
    : Preliminary research found honey applied to the skin to be effective in treating labial but not genital herpes. More research is needed in this area to draw a firm conclusion.

  • Avoid if allergic or hypersensitive to honey, pollen, celery, or bees. Honey is generally considered safe in the recommended doses. Avoid honey from the genus Rhododendron, because it may cause a toxic reaction. Avoid in infants younger than 12 months of age. Use cautiously with antibiotics. Potentially harmful contaminants (like C. botulinum or grayanotoxins) can be found in some types of honey and should be used cautiously in pregnant or breastfeeding women.
    Arrhythmia (an irregular heartbeat), atrioventricular or intraventricular block (an interruption of electrical signals in the heart), blurred vision, bradycardia (a slow heart rate), convulsions, diarrhea, difficulty breathing, dizziness, increased maggot infestation of wounds, infant botulism (food poisoning), leucocytosis (increased white blood cells), low blood pressure, mild paralysis, nausea, sweating, ulcers, vomiting, weakness, and Wolff-Parkinson-White syndrome are potential symptoms of honey intoxication.
  • Hypnotherapy
    : A small study showed the potential benefit of a hypnotherapeutic treatment program for patients suffering from recurrent facial herpes infections. Further research is needed to confirm these results.

  • Use cautiously with mental illnesses like psychosis, schizophrenia, manic depression, multiple personality disorder, or dissociative disorders. Use cautiously with seizure disorders.
  • Licorice
    : Some research suggests that licorice extracts, or deglycyrrhizinated licorice (DGL, licorice processed without the glycyrrhiza chemical component believed to be responsible for adverse effects), may provide some benefit for treating canker sores and the herpes simplex virus. However, studies have been small. The safety of DGL makes it an attractive therapy if it does speed healing of these sores, but it is not clear at this time whether there is truly any benefit. More research is needed in this area.

  • Avoid with a known allergy to licorice, any component of licorice, or any member of the Fabaceae (Leguminosae) plant family. Avoid with congestive heart failure, coronary heart disease, kidney or liver disease, fluid retention, high blood pressure, hormonal abnormalities, or use of diuretics. Licorice can cause abnormally low testosterone levels in men or high prolactin or estrogen levels in women. This may make it difficult to become pregnant and may cause menstrual abnormalities. In general, healthcare professionals recommend that prescription drugs should be taken one hour before or two hours after licorice, because licorice may increase the absorption of many drugs and may affect the liver’s processing of certain drugs.
  • Lycopene
    : Lycopene is a red pigment and antioxidant found in tomatoes and other red fruits and vegetables.
    Limited evidence suggests that lycopene (with or without steroids) may help patients with oral submucous fibrosis (a disease of the oral cavity characterized by inflammation and fibrosis of the mucosal tissues).

  • Avoid if allergic to tomatoes or to lycopene. Due to a lack of conclusive data, avoid if pregnant or breastfeeding.
  • Perilla
    : Preliminary evidence suggests there is a lack of benefit of perilla oil vs. soybean oil for aphthous stomatitis prevention. Further clinical trials are required before a firm conclusion can be made.

  • Avoid if allergic or hypersensitive to perilla or members of the Lamiaceae (Labiatae) family. Use cautiously with cancer, low HDL cholesterol, and immune disorders. Use cautiously if taking NSAIDs or barbiturates. Avoid if pregnant or breastfeeding.
  • Podophyllum
    : Podophyllum and its derivatives are known to be active cytotoxic agents, which may be beneficial in the treatment of hairy leukoplakia. Additional study is needed before a firm conclusion regarding effectiveness can be made.

  • Avoid if allergic or hypersensitive to podophyllum or to members of the Berberidaceae family. Podophyllum, when applied topically, may be absorbed through the skin and cause irritation of the stomach and intestines. Podophyllum toxicity may cause heart palpitations and blood pressure changes, muscle paralysis, difficulty walking, confusion, and convulsions. Using podophyllum and laxatives may result in dehydration and electrolyte depletion. Use cautiously with arrhythmia, Crohn’s disease, cardiovascular problems, gallbladder disease or gallstones, high blood pressure, irritable bowel syndrome, liver insufficiency, muscular or neurologic disorders, psychosis, or kidney insufficiency. Use cautiously if taking antimitotic agents like vincristine, antipsychotic agents, or laxatives. Avoid if pregnant or breastfeeding; documented cases of birth defects and fetal deaths have been associated with podophyllum used during pregnancy.
  • Probiotics
    : Probiotics are food or dietary supplements that contain live bacteria in amounts beneficial to health. Early research suggests that cheese containing probiotics may help reduce the risk of the fungal mouth infection thrush in the elderly. More research is needed in this area.

  • Probiotics are generally considered safe and well tolerated. Avoid if allergic or hypersensitive to probiotics. Use cautiously if lactose intolerant. Caution is advised when using probiotics in neonates born prematurely or with immune deficiency.
  • Propolis
    : There is some evidence that propolis, a bee product, taken by mouth may help reduce outbreaks of canker sores. Further research is needed to confirm this.

  • Avoid if allergic or hypersensitive to propolis, black poplar (Populus nigra), poplar bud, bee stings, bee products, honey, or balsam of Peru. Severe allergic reactions have been reported. Use cautiously with asthma or gastrointestinal disorders. Avoid if pregnant or breastfeeding, because of the high alcohol content in some products.
  • Rhubarb
    : A clinical trial indicated that rhubarb-sage extract cream applied to the skin may reduce the symptoms of herpes. More high-quality studies using rhubarb as a monotherapy (a single medication or therapy adequate to treat the condition) are needed to discern rhubarb’s effect on herpes symptoms.

  • Avoid if allergic or hypersensitive to rhubarb, its constituents, or related plants from the Polygonaceae family. Avoid using rhubarb for more than two weeks, because it may induce tolerance in the colon, melanosis coli, laxative dependence, pathological or diseased alterations to the colonic smooth muscles, and substantial loss of electrolytes. Caution is advised in patients with atony, colitis, Crohn’s disease, dehydration with electrolyte depletion, diarrhea, hemorrhoids, insufficient liver function, intestinal obstruction or ileus, irritable bowel syndrome, menstruation, renal disorders, ulcerative colitis, and urinary problems. Avoid handling rhubarb leaves, as they may cause contact dermatitis. Avoid in children younger than age 12, due to water depletion. Use cautiously with bleeding disorders, cardiac conditions, coagulation therapy, constipation, a history of kidney stones, or thin or brittle bones. Use cautiously if taking antipsychotic drugs or oral drugs, herbs or supplements (including calcium, iron, and zinc).
  • Sage
    Early evidence suggests that sage extracts may be useful in the treatment of herpes skin manifestations. More research is needed in this area.

  • Avoid if allergic or hypersensitive to sage species, their constituents, or to members of the Lamiaceae family. Use cautiously with hypertension (high blood pressure). Use the essential oil or tinctures cautiously in patients with epilepsy. Avoid with previous anaphylaxis (serious or life-threatening allergic reaction) to sage species, their constituents, or to members of the Lamiaceae family. Avoid if pregnant or breastfeeding.
  • Spirulina
    : Preliminary research has not clearly shown benefits of spirulina (a microscopic blue-green algae) in the treatment of oral leukoplakia. More research is needed in this area.

  • Avoid if allergic or hypersensitive to spirulina or blue-green algae. Use cautiously with phenylketonuria (a genetic disorder of a liver enzyme that disrupts normal body functions), autoimmune diseases, bleeding disorders, diabetes, and osteoporosis. Use cautiously with products containing the blue-green algae species Anabaena spp., Aphanizomenon spp., and Microcystis spp.; in underweight patients, or in those taking antiobesity agents or appetite suppressants; or if consuming a high-protein diet. Avoid in children and in pregnancy and breastfeeding.
  • Tea tree oil
    : In laboratory studies, tea tree oil has been shown to kill fungus and yeast such as Candida albicans. However, at this time, there is not enough information available from human studies to make conclusions on the use of tea tree oil for the fungal mouth infection thrush.

  • Tea tree oil may be toxic when taken by mouth and therefore should not be swallowed.
    Avoid in patients allergic or hypersensitive to tea tree oil, any of its constituents, balsam of Peru, benzoin, colophony (rosin) tinctures, eucalyptol, or other members of the Myrtle (Myrtaceae) family. Avoid taking tea tree oil by mouth. Avoid if taking anticancer agents. Use tea tree oil applied to the skin cautiously in patients with previous tea tree oil use. Avoid if pregnant or breastfeeding.
  • Zinc
    : Zinc has been studied for recurrent aphthous stomatitis (RAS) and radiation-induced mucositis. Additional research is needed to confirm early research results.

  • Zinc is generally considered safe when taken at the recommended dosages. Avoid zinc chloride, since studies have not been done on its safety or effectiveness. Avoid with kidney disease. Use cautiously if pregnant or breastfeeding.


Fair negative scientific evidence

  • Aloe
    : There is early evidence that oral aloe vera does not prevent or improve mucositis (mouth sores) associated with radiation therapy.

  • Avoid if allergic to aloe or other plants of the Liliaceae family (garlic, onions, tulips). Avoid injecting aloe. Avoid applying to open surgical wounds or pressure ulcers. Avoid taking by mouth with diarrhea, bowel blockage, intestinal diseases, bloody stools, hepatitis, arrhythmia (a history of irregular heartbeat), electrolyte imbalances, diabetes, heart disease, or kidney disease. Avoid taking by mouth if pregnant or breastfeeding.


  • General: It is recommended by healthcare professionals to call a dentist immediately if there are problems with the teeth, gums, or oral cavity.
  • Limit tobacco use: In addition to the general health risks posed by tobacco, smokers have four times the risk of developing gum disease compared to nonsmokers. Tobacco use in any form, such as cigarettes, pipes, and smokeless (chewing) tobacco, increases the risk for gum disease, oral and throat cancers, and candidiasis (oral fungal infection). Chewing tobacco containing sugar increases the risk of tooth decay.
  • Diet modification: Healthcare professionals suggest that adults and children avoid snacks with high levels of sugars and starches and limit the number of snacks eaten throughout the day. The recommended five daily servings of fiber-rich fruits and vegetables stimulate salivary flow to aid in decreasing tooth decay.
  • Regular dental checkups: It is recommended by healthcare professionals to visit the dentist regularly, preferably every six months for cleaning. Checkups may detect early signs of oral health problems and can lead to treatments that will prevent further damage and, in some cases, reverse the problem. Professional prophylaxis (tooth cleaning) is also important for preventing oral problems, especially when self-care is difficult.
  • Oral health checkup before cancer treatment: It is recommended to have an oral health checkup before beginning cancer treatment. Radiation to the head or neck and/or chemotherapy may cause problems for the teeth and gums. Treating existing oral health problems before cancer therapy may help prevent or limit oral complications or tissue damage.
  • Acrodermatitis enteropathica: Acrodermatitis enteropathica is an inherited condition and thus preventive measures are unknown at this time.
  • Canker sores: Canker sore prevention measures are currently unknown. While many techniques have been proposed, there is little evidence of their effectiveness.
  • Cold sores (HSV-1, herpes labialis, oral herpes): Taking steps to guard against the development of cold sores, to prevent spreading them to other parts of the body, or to avoid passing them along to another person is important when dealing with oral herpes.
  • Cold sores are contagious at all stages. However, they are most contagious when the blisters break open and release moist secretions. As a result, kissing and sharing common items that touch the lips and skin around them, such as utensils, towels, and water glasses, can spread the virus when blisters are present, according to the National Institutes of Health (NIH).
  • In individuals with depressed immune systems, the virus can be spread even after the skin appears to be healed.
  • Washing the hands carefully before touching another person when a cold sore is present is very important. The eyes and genital area may be particularly susceptible to the spread of the virus.
  • Avoiding or preventing conditions that stress the body, such as poor diet, not getting enough sleep, or staying in the sun for long periods of time without applying sunblock is very important in preventing oral herpes outbreaks.
  • Leukoplakia:
    Leukoplakia may be prevented by avoiding the use of all tobacco products and avoiding or limiting alcohol use (especially in combination with tobacco).
  • Mucositis: While this condition has been heavily studied, effective approaches for the prevention of oral mucositis are lacking. Recent clinical trials have identified potentially effective approaches for preventing mucositis, including the use of allopurinol, growth factors and povidone-based mouthwashes, hydrolytic enzymes (phospholipases, lipases, esterases), amifostine (a chemotherapy agent), sucralfate (a gastric ulcer agent), antibiotics, honey, low-intensity laser, oral hygiene, analgesics, and anti-inflammatory drugs (such as ibuprofen (Motrin®) and naproxen (Naprosyn®)). The American Academy of Family Physicians (AAFP) recommends seeing a dentist two weeks prior to beginning cancer treatment and checking the mouth every day to observe any changes.
  • Oral candidiasis (oral thrush): Oral candidiasis or oral thrush yeast infections may be prevented with good oral hygiene, such as cleaning dentures appropriately and brushing the teeth.

Author Information

  • This information has been edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (


Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to Selected references are listed below.

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    View Abstract