Do Chronic Canker Sores Hint at Autoimmune Conditions?

Many people experience canker sores from time to time. Eating foods that are too acidic or too spicy, or biting your tongue or cheek can all cause these painful mouth ulcers.
But when a canker sore lingers for longer than normal or keeps coming back, what does that mean? Could it hint at a deeper health issue? Could chronic canker sores indicate an autoimmune condition?
What Is a Canker Sore?
A canker sore (also called an aphthous ulcer) is a shallow lesion that develops inside the lips and mouth. These white, gray, or yellow ulcers usually measure between 1-4 millimeters (mm) in diameter with a bright red or pink border.
Even though they can be very painful, canker sores are not dangerous. They don't spread from person to person, and they aren't caused by a virus.
Canker sores are very common and usually hurt most in the first few days after they form. Most canker sores heal completely within two weeks.
Two types of canker sores have been associated with autoimmune conditions: chronic canker sores and complex canker sores.
Chronic Canker Sores
A chronic health condition is a health issue that persists for more than one year and limits your daily activities or requires ongoing medical attention. Not all chronic diseases are life-threatening, but they can disrupt and hinder your quality of life.
Chronic canker sores, also referred to as recurrent aphthous stomatitis, are canker sores that occur repeatedly and impact your daily life. This can include regular canker sores that recur as well as complex canker sores that recur.
Complex Canker Sores
Size is the most obvious difference between a regular canker sore and a complex canker sore. Regular canker sores stay under 4 mm in diameter, but complex canker sores can reach 5 mm or larger.
Complex canker sores also linger for up to six weeks at a time instead of healing on their own over the span of a week or two.
Complex canker sores may be accompanied by seemingly unrelated symptoms, such as lethargy, fever, and swollen lymph nodes. This indicates that your complex canker sore isn't simply an oral health issue but a sign of a more serious underlying problem.
What Is Autoimmune Disease?
Your immune system is designed to protect your body against foreign invaders. Autoimmune diseases occur when the body mistakenly identifies its own cells as foreign invaders. The body then releases autoantibodies that attack its own cells.
Depending on the particular part of the body attacking itself, a variety of autoimmune conditions can develop. Some of the most well-known autoimmune diseases include:
- Rheumatoid arthritis — the immune system attacks the joints, causing pain, inflammation, and eventually permanent joint damage.
- Celiac disease — the immune system attacks the small intestine in response to consumption of a protein called gluten. It can cause pain, inflammation, and an inability to absorb vital nutrients.
- Type 1 diabetes — the body attacks its own insulin production cells in the pancreas, resulting in a loss of insulin and an inability to regulate blood sugar.
- Crohn's disease — a subtype of inflammatory bowel disease that causes inflammation in the digestive tract. Crohn's can be painful and debilitating, and it can sometimes lead to life-threatening complications.
Are Chronic Canker Sores Connected to Autoimmune Diseases?
Some researchers believe there is a connection between chronic canker sores and autoimmune diseases. Certain specific autoimmune diseases have been linked to complex and chronic canker sores, including pemphigus, Crohn's disease, and Behcet's disease.
Pemphigus is a collection of rare autoimmune skin disorders that cause blisters on the skin and mucous membranes. These blisters usually erupt on the neck, underarms, scalp, eyes, nose, mouth, and genitals and can resemble canker sores when present in the mouth.
Inflammatory bowel diseases can also lead to chronic canker sores. Up to 30% of Crohn's disease patients and up to 10% of ulcerative colitis patients develop canker sores in addition to gastrointestinal symptoms.
Behcet's disease causes inflammation of the blood vessels throughout the body. This rare autoimmune disease can lead to inflammation in the eyes, joints, and brain as well as sores on the genitals, skin, and mouth (canker sores).

Red Light Therapy for Chronic Canker Sores
If you suffer from complex or chronic canker sores, particularly in combination with other concerning symptoms, speak to your doctor about whether you could have an autoimmune condition.
Regardless of the reasons for your canker sores, red light therapy can help. This treatment has been clinically proven to reduce the pain and healing time of canker sores.
The Luminance Mouth Sore Treatment device is an FDA-registered device that uses this kind of high-powered light technology to help manage canker sore pain and healing.