ulcer

Any persistent breach in a body surface (skin or mucous membrane). It may be caused by infection, irritation, or tumour and is often inflamed. Common ulcers include aphthous (mouth), gastric (stomach), duodenal, decubitus ulcers (pressure sores), and those complicating varicose veins.

Treatment of ulcers depends on the site. Drugs are the first line of attack against peptic ulcers (those in the digestive tract), though surgery may become necessary. Bleeding stomach ulcers can be repaired without an operation by the use of endoscopy: a flexible fibre-optic tube is passed into the stomach and under direct vision fine instruments are used to repair the tissues.

Stomach ulcers are linked to the bacterium Helicobacter pylori found in the stomachs of 60% of adults in the West by the time they are 60. One in six infected with the bacterium develops ulcers. They are twice as common in those with blood type O, which may be because H. pylori attaches itself to the stomach lining by a string of sugar found only in that blood group.

The presence of H. pylori in the stomach can be detected by a breath-test devised in 1994. The patient swallows a small amount of urea, which is broken down only if the bacteria are present, and shortly afterwards breathes into a device which measures the level of carbon isotopes exhaled.