Mouth Sores and Inflammation

Viruses are the most common infectious causes of mouth sores. Cold sores of the lip and, less commonly, ulcers on the palate caused by the herpes simplex virus Herpes Simplex Virus (HSV) Infections Herpes simplex virus infection causes recurring episodes of small, painful, fluid-filled blisters on the skin, mouth, lips (cold sores), eyes, or genitals. This very contagious viral infection... read more are perhaps the most well known. However, many other viruses can cause mouth sores. Varicella-zoster, the virus responsible for chickenpox as well as the painful skin disorder called shingles Shingles Shingles is a painful skin rash caused by a viral infection that results from reactivation of the varicella-zoster virus, the virus that causes chickenpox. What causes the virus to reactive... read more , can cause multiple sores to form on one side of the mouth. These sores are the result of a flare-up of the virus, which, just like herpes simplex virus, never leaves the body. Occasionally, the mouth remains painful for months or years or even permanently after the sores have healed.

A bacterial infection can lead to sores and swelling in the mouth. Infections may be caused by an overgrowth of organisms normally present in the mouth or by newly introduced organisms, such as the bacteria that cause syphilis or gonorrhea Gonorrhea Gonorrhea is a sexually transmitted infection caused by the bacteria Neisseria gonorrhoeae, which infect the lining of the urethra, cervix, rectum, or throat, or the membranes that cover... read more . Bacterial infections from teeth or gums can spread to form a pus-filled pocket of infection (abscess) or cause widespread inflammation (cellulitis Cellulitis Cellulitis is a spreading bacterial infection of the skin and the tissues immediately beneath the skin. This infection is most often caused by streptococci or staphylococci. Redness, pain, and... read more ).

Syphilis Syphilis Syphilis is a sexually transmitted infection caused by the bacteria Treponema pallidum. It can occur in three stages of symptoms, separated by periods of apparent good health. Syphilis... read more may produce a red, painless sore (chancre) that develops in the mouth or on the lips during the early stage of infection. The sore usually heals after several weeks. About 4 to 10 weeks later, a white area (mucous patch) may form on the lip or inside the mouth if the syphilis has not been treated. Both the chancre and the mucous patch are highly contagious, and kissing may spread the disease during these stages. In late-stage syphilis, a hole (gumma) may appear in the palate or tongue. The disease is not contagious at this stage.

The yeast Candida albicans is a normal resident of the mouth. However, it can overgrow in people who have taken antibiotics or corticosteroids or who have a weak immune system, such as people with AIDS Acquired immunodeficiency syndrome (AIDS) Human immunodeficiency virus (HIV) infection is a viral infection that progressively destroys certain white blood cells and is treated with antiretroviral medications. If untreated, it can cause... read more . Candida can cause whitish, cheese-like patches that destroy the top layer of the lining of the mouth (thrush) when wiped off. Sometimes only flat, red areas appear.

Any type of damage or injury to the mouth, for instance, when the inside of the cheek is accidentally bitten or scraped by broken or jagged teeth or poor-fitting dentures, can cause blisters (vesicles or bullae) or ulcers to form in the mouth. Typically, the surface of a blister breaks down quickly (ruptures), forming an ulcer.

Many foods and chemicals can be irritating or trigger a type of allergic reaction, causing mouth sores. Acidic foods, cinnamon flavoring, or astringents may be particularly irritating, as can certain ingredients in common substances such as toothpaste, mouthwash, candy, and gum.

Tobacco use can cause mouth sores. The sores most likely result from exposure to the irritants, toxins, and carcinogens found naturally in tobacco products but may also result from the drying effects on the lining of the mouth, the high temperatures in the mouth, changes to the acidity of the mouth, or decreased resistance to viral, bacterial, and fungal infections.

The most common drugs causing mouth sores include certain cancer chemotherapy drugs. Drugs containing gold, which were once used to treat rheumatoid arthritis and some other autoimmune disorders, can also cause mouth sores, but these drugs are rarely used because safer and more effective drugs are now available. Radiation therapy is also a common cause of mouth sores. Rarely, people may develop mouth sores after taking antibiotics.

Many diseases affect the mouth along with other parts of the body. Behçet disease Behçet Disease Behçet disease is chronic blood vessel inflammation (vasculitis) that can cause painful mouth and genital sores, skin lesions, and eye problems. The joints, nervous system, and digestive tract... read more , an inflammatory disease affecting many organs, including the eyes, genitals, skin, joints, blood vessels, brain, and gastrointestinal tract, can cause recurring, painful mouth sores. Stevens-Johnson syndrome Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN) Stevens-Johnson syndrome and toxic epidermal necrolysis are two forms of the same life-threatening skin disorder that cause rash, skin peeling, and sores on the mucous membranes. (See also Overview... read more , a type of allergic reaction, causes skin blisters and mouth sores. Some people with inflammatory bowel disease Overview of Inflammatory Bowel Disease (IBD) In inflammatory bowel diseases, the intestine (bowel) becomes inflamed, often causing recurring abdominal pain and diarrhea. The 2 primary types of inflammatory bowel disease (IBD) are Crohn... read more also develop mouth sores. People with severe celiac disease Celiac Disease Celiac disease is a hereditary intolerance to gluten (a protein found in wheat, barley, and rye) that causes characteristic changes in the lining of the small intestine, resulting in malabsorption... read more , which is caused by an intolerance to gluten (a component of wheat and some other grains), often develop mouth sores. Lichen planus Lichen Planus Lichen planus, a recurring itchy disease, starts as a rash of small, separate, red or purple bumps that then combine and become rough, scaly patches. The cause is unknown but may be a reaction... read more , a skin disease, can rarely cause mouth sores, although usually these sores are not as uncomfortable as those on the skin. Pemphigus vulgaris Pemphigus Vulgaris Pemphigus vulgaris is a rare, severe autoimmune disorder in which blisters of varying sizes break out on the skin and on the lining of the mouth and other mucous membranes. Pemphigus vulgaris... read more and bullous pemphigoid Bullous Pemphigoid Bullous pemphigoid is an autoimmune disease that causes blistering of the skin. Bullous pemphigoid is an autoimmune disorder that occurs when the immune system attacks the skin and causes blistering... read more , both skin diseases, can also cause blisters to form in the mouth.

Nutritional deficiencies of iron Iron Deficiency Iron deficiency is a common cause of anemia, a condition in which the number of red blood cells is low. Iron deficiency usually results from loss of blood in adults (including bleeding from... read more , vitamin B6 Vitamin B6 Deficiency Vitamin B6 is in most foods, but people can have vitamin B6 deficiency if they do not absorb it properly. Many foods contain vitamin B6, but extensive processing can remove the vitamin. People... read more , vitamin B12 Vitamin B12 Deficiency Vitamin B12 deficiency can occur in vegans who do not take supplements or as a result of an absorption disorder. Anemia develops, causing paleness, weakness, fatigue, and, if severe, shortness... read more , and vitamin C Vitamin C Deficiency In countries with low rates of food insecurity, vitamin C deficiency can occur from a diet low in vitamin C, but severe deficiency (causing scurvy) is uncommon. Not eating enough fresh fruits... read more may also cause mouth sores.

Topical treatments are substances applied directly to an affected part of the body. Topical treatments for mouth sores include

An anesthetic such as dyclonine or lidocaine may be used as a mouth rinse. However, because these mouth rinses numb the mouth and throat and thus may make swallowing difficult, children using them should be watched to ensure that they do not choke on their food. Lidocaine in a thicker preparation (viscous lidocaine) can also be swabbed directly on the mouth sore.

Protective coatings containing sucralfate and aluminum-magnesium antacids can be soothing when applied as a rinse. Many doctors add other ingredients such as lidocaine and/or diphenhydramine (an antihistamine). Amlexanox paste is another alternative. Mouth rinses that contain alcohol (ethanol) should be avoided, because they may actually make the mouth sores worse.

Once doctors are sure that the sore is not caused by an infection, they may prescribe a corticosteroid rinse or a corticosteroid gel to be applied to each sore.

Some mouth sores can be treated with a low-powered laser, which relieves pain immediately and often prevents sores from returning. Chemically burning the sore with a small stick coated with silver nitrate may similarly relieve pain but is not as effective as a laser.