An ulcer is an open sore or a break in a bodily membrane, such as the skin or a mucous membrane. These lesions involve a loss of surface tissue, often with inflammation. Ulcers can develop in various parts of the body, and their location provides important clues for understanding their type and guiding diagnosis.
Gastrointestinal Ulcers
Ulcers commonly form within the gastrointestinal (GI) tract, particularly in the upper digestive system, where they are known as peptic ulcers. These include sores in the esophagus, stomach, and the initial segment of the small intestine (duodenum). The term “peptic” relates to digestion and the enzyme pepsin, which, along with stomach acid, can damage the protective lining of these organs.
Esophageal ulcers develop in the lining of the tube connecting the throat to the stomach, often at its lower end. A common symptom is a burning pain in the chest. Symptoms can also include difficulty or pain when swallowing, indigestion, nausea, or a sour taste in the mouth.
Gastric ulcers appear in the stomach lining, while duodenal ulcers form in the duodenum. Both types can cause a gnawing or burning pain in the upper abdomen. This pain may occur when the stomach is empty, during the night, or can be temporarily relieved by eating or taking antacids. Other symptoms can include bloating, belching, nausea, vomiting, fullness after eating, or unexplained weight loss.
Cutaneous and Mucosal Ulcers
Ulcers also manifest on external skin surfaces and other mucosal linings. This group includes pressure ulcers, venous ulcers, arterial ulcers, and mouth ulcers.
Pressure ulcers, also known as bedsores or decubitus ulcers, arise over bony areas of the body such as the heels, elbows, hips, and tailbone. They begin as discolored patches of skin that do not blanch when pressed, appearing red on lighter skin or purple/blue on darker skin. The affected area can feel warm, spongy, or hard, and may be painful or itchy.
Venous ulcers appear on the lower legs, particularly on the inside of the leg between the knee and the ankle. These open sores are painful and can take weeks or months to heal. Surrounding symptoms include swollen ankles, skin discoloration (reddish-brown or purple), hardened skin, a heavy sensation in the legs, or flaky, itchy skin.
Arterial ulcers, also termed ischemic ulcers, form on the lower legs and feet, including between or on the tips of the toes, on the heels, or the outer ankle. These ulcers are very painful, especially at night, and have a “punched-out” appearance with well-defined, even borders. The affected limb can feel cool to the touch, and the skin may appear shiny, thin, and hairless.
Mouth ulcers, or aphthous ulcers (canker sores), are painful lesions that develop on the soft tissues inside the mouth, such as the inner cheeks, lips, tongue, or at the base of the gums. They present with a white or yellow center surrounded by a bright red border. These sores are not contagious but can make eating and talking uncomfortable.
Factors Influencing Ulcer Formation at Specific Sites
The formation of ulcers is influenced by factors unique to their location. In the gastrointestinal tract, the delicate balance between protective mucosal lining and aggressive stomach acid is disrupted. This imbalance results from infection with Helicobacter pylori bacteria, which can colonize the gastric mucosa and cause inflammation, impairing the lining’s ability to secrete bicarbonate.
Regular use of nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen or aspirin, also contributes to GI ulcer formation. NSAIDs can damage the stomach lining by inhibiting the production of prostaglandins, substances that protect the mucosa by promoting mucus and bicarbonate secretion and maintaining blood flow. When both H. pylori infection and NSAID use are present, the risk of developing peptic ulcers increases.
For cutaneous ulcers, the underlying causes relate to compromised blood supply or sustained external forces. Pressure ulcers develop when prolonged pressure on an area, especially over bony prominences, compresses local capillaries and reduces blood flow to the tissues. This deprivation of oxygen and nutrients leads to tissue ischemia and necrosis. Shear forces, such as sliding in a bed, can also distort tissue and contribute to their formation.
Venous ulcers result from chronic venous insufficiency, where damaged valves in leg veins prevent blood from flowing back to the heart. This leads to blood pooling in the lower extremities, increasing pressure in the veins and damaging skin tissue. The sustained venous hypertension causes skin breakdown and ulcer development.
Arterial ulcers are caused by inadequate blood supply to the affected tissues, a condition known as ischemia. This stems from peripheral artery disease (PAD), where arteries supplying blood to the legs and feet become narrowed or blocked due to plaque buildup. When blood flow is restricted, tissues do not receive enough oxygen and nutrients, leading to tissue damage and ulcer formation.
Diagnostic Methods Based on Location
The location of an ulcer guides the diagnostic methods. For internal gastrointestinal ulcers, an upper endoscopy, also known as esophagogastroduodenoscopy (EGD), is the primary diagnostic tool. This procedure involves inserting a thin, flexible tube with a camera (endoscope) through the mouth to inspect the lining of the esophagus, stomach, and duodenum.
During an EGD, the doctor can visualize ulcers, assess their characteristics, and identify active bleeding. The endoscope also allows for the collection of tissue samples (biopsies) from suspicious areas. These biopsies are examined under a microscope to test for H. pylori infection and rule out other conditions such as cancer.
For cutaneous ulcers, diagnosis begins with a physical examination of the affected area. The provider assesses the ulcer’s appearance, size, depth, and the condition of the surrounding skin. They also check for signs of infection, such as redness, swelling, or discharge.
For chronic or atypical cutaneous ulcers, a tissue sample (biopsy) may be taken from the edge of the ulcer. This sample is analyzed to determine the underlying cause, rule out malignancy, or identify cellular characteristics. Additional tests, such as blood flow assessments for arterial or venous ulcers, may also be performed to assess circulatory health.