Table: Some Causes of Mouth Sores - Merck Manuals Consumer Version

Some Causes of Mouth Sores

Category	Examples
Bacterial infections	Gonorrhea Gonorrhea Gonorrhea is a sexually transmitted infection caused by the bacteria Neisseria gonorrhoeae, which infect the lining of the urethra, cervix, rectum, and throat or the membranes that cover... read more Syphilis Syphilis Syphilis is a sexually transmitted infection caused by the bacteria Treponema pallidum. Syphilis can occur in three stages of symptoms, separated by periods of apparent good health. It... read more Trench mouth Acute Necrotizing Ulcerative Gingivitis (ANUG) Acute necrotizing ulcerative gingivitis (ANUG) is a painful infection of the gums that causes fever, sometimes foul-smelling breath, and feeling ill. If the normal bacteria in the mouth overgrow... read more (acute necrotizing ulcerative gingivitis)
Fungal infections	Candidal infections (most common)
Viral infections Overview of Viral Infections A virus is composed of nucleic acid, either DNA or RNA, surrounded by a protein coat. It requires a living cell in which to multiply. A viral infection can lead to a spectrum of symptoms from... read more	Chickenpox (varicella zoster) Herpes simplex infection 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 (primary or secondary) 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 (reactivation of varicella zoster) Others (such as infection by coxsackievirus, cytomegalovirus, Epstein-Barr virus, or HIV, as well as genital warts, influenza, and measles)
Systemic disorders	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 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 or 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 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 Cyclic neutropenia Erythema multiforme Erythema Multiforme Erythema multiforme is an inflammatory skin disorder characterized by patches of red, raised skin that often look like targets and usually are distributed symmetrically over the body. (See also... read more Inflammatory bowel disease Inflammatory Bowel Diseases (IBD) Iron deficiency 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 Kawasaki disease Kawasaki Disease Kawasaki disease causes inflammation of blood vessels throughout the body. The cause of Kawasaki disease is unknown but may be associated with an infection. Children typically have fever, rash... read more Leukemia Overview of Leukemia Leukemias are cancers of white blood cells or of cells that develop into white blood cells. White blood cells develop from stem cells in the bone marrow. Sometimes the development goes awry... read more Platelet disorders 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 Thrombotic thrombocytopenia Vitamin B deficiency Niacin Deficiency Niacin deficiency (causing pellagra) is uncommon in countries with low rates of food insecurity. Many people with niacin deficiency also have deficiencies of protein, riboflavin (a B vitamin)... read more (pellagra) Vitamin C deficiency 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 (scurvy) Vitamin B12 deficiency
Drugs	Antibiotics Overview of Antibiotics Antibiotics are drugs used to treat bacterial infections. They are not effective against viral infections and most other infections. Antibiotics either kill bacteria or stop them from reproducing... read more * Antiseizure drugs Antiseizure drugs In seizure disorders, the brain's electrical activity is periodically disturbed, resulting in some degree of temporary brain dysfunction. Many people have unusual sensations just before a seizure... read more * Barbiturates Misuse of Antianxiety Medications and Sedatives Antianxiety and sedative medications are prescription drugs used to relieve anxiety and/or help with sleep, but their use can result in dependency and a substance use disorder. Using prescription... read more * Chemotherapy drugs Chemotherapy and Other Systemic Cancer Treatments Systemic treatments are those that have effects throughout the body rather than being applied directly to the cancer. Chemotherapy is a form of systemic treatment that uses drugs to kill cancer... read more Gold Iodides* Nonsteroidal anti-inflammatory drugs (NSAIDs) Nonsteroidal Anti-Inflammatory Drugs Pain relievers (analgesics) are the main drugs used to treat pain. Doctors choose a pain reliever based on the type and duration of pain and on the drug's likely benefits and risks. Most pain... read more *
Physical irritation	Cheek-biting or lip-biting habits Dentures that fit poorly Jagged or broken teeth
Irritants and allergies	Acidic foods Allergic reaction to ingredients in toothpaste, mouthwash, candy, gum, dyes, or lipstick Aspirin, when applied to tissues inside the mouth Dental appliances containing nickel or palladium Occupational exposure to dyes, heavy metals, acid fumes, or metal or mineral dust Tobacco (chewing and/or smoking)
Other	Burning mouth syndrome Burning Mouth Syndrome Burning mouth syndrome is mouth pain, usually involving the tongue, in people who do not have any visible sores or abnormalities in their mouth. Burning mouth syndrome probably represents a... read more Canker sores ( recurrent aphthous stomatitis Recurrent Aphthous Stomatitis Recurrent aphthous stomatitis (canker sores, or aphthous ulcers) is the presence of small, painful sores (ulcers) inside the mouth that typically begin in childhood and recur frequently. Mouth... read more ) 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 may be a reaction to certain drugs... read more Radiation therapy to the head and neck
* Rare causes of mouth sores.