Mouth ulcer

A mouth ulcer, also known as an aphtha, is a break in the mucous membrane of the oral cavity.

These sores are often called canker sores or salt blisters. They can appear as a single sore or as a "crop" of multiple ulcers at once. While most mouth ulcers are not caused by anything serious, they can cause significant pain. This discomfort often changes how a person eats. People may avoid foods that are acidic, sugary, salty, or spicy to prevent stinging. In rare cases, an ulcer that fails to heal may be a sign of oral cancer.

To understand an ulcer, we must look at how deep the damage goes. An ulcer is a tissue defect that penetrates the epithelial-connective tissue border. This means the break reaches deep into the submucosa, or even into the muscle. It is much deeper than an erosion. An erosion is a superficial breach that only affects the top epithelial layer.

There is also a middle stage called excoriation. This is deeper than an erosion but shallower than an ulcer. It can cause small pinhead spots of bleeding because it exposes tiny capillary loops. When a full ulcer forms, it creates a crater-like shape in the mouth.

When an ulcer is visible, it has specific physical characteristics. The base of the ulcer often takes on a yellow-grey color. This color comes from a layer called a fibrinous exudate. You might also notice a "halo" around the sore. This halo is a red ring caused by inflammation in the surrounding mucosa. Swelling, or edema, can also occur in the area.

If the trauma causing the ulcer is chronic, the edges might become keratotic. This means the margin of the ulcer looks white and thickened.

Many different triggers can cause these lesions to form. Local trauma is one of the most common causes. This includes physical damage like accidentally biting a cheek or lip. Sharp edges from broken dental fillings, crowns, or braces can also rub the tissue. Even eating hard foods, such as potato chips, can cause damage. Thermal burns are another cause, often from eating very hot food or beverages.

Electrical burns can also occur, sometimes caused by children chewing on live wires. Even chemical injuries can happen if strong caustic chemicals touch the mouth.

Some ulcers are caused by internal medical conditions rather than outside injury. One common condition is aphthous stomatitis. This is characterized by the recurrent formation of ulcers for reasons that are largely unknown. Other causes include vitamin deficiencies, such as a lack of Vitamin C which can lead to scurvy. Certain medications or the use of SLS can also be factors. Some people experience mouth ulcers due to an immunodeficiency. This means the immune system is not working at full strength. Conditions like HIV, mononucleosis, or chemotherapy can cause this. Chemotherapy drugs target fast-growing cells, but the lining of the mouth also has a high turnover rate. This makes oral ulceration, or mucositis, a common side effect.

Doctors use specific methods to diagnose the cause of an ulcer. They begin with a medical history and an oral examination. They look at the size, color, and location of the lesion. They also check if the ulcer is hard to the touch or has rolled edges. A single, hard ulcer with rolled margins might suggest a malignant lesion. In contrast, multiple ulcers are very unlikely to be cancer.

If an ulcer does not heal within two or three weeks, a professional should examine it. A dentist or surgeon may perform a biopsy. This is a small procedure where a sample of the tissue is removed to be looked at under a microscope.

Understanding these patterns helps connect mouth health to the rest of the body. The mouth acts as a transition between the skin and the gastrointestinal tract. Because of this, skin conditions can sometimes show up in the mouth. Similarly, some digestive issues, like Crohn's disease, might present only in the mouth. By watching how ulcers form and heal, healthcare providers can learn about a person's overall immune system and nutritional health.