Helicobacter pylori-negative ulcer disease.

The proportion of ulcer patients without evidence of Helicobacter pylori infection varies considerably in different parts of the world, which may be explained by the different prevalence of H. pylori infection in the background population. In any ulcer patient with an H. pylori-negative test, it is important to consider that the test may be falsely negative due to treatment with antibiotics, bismuth preparations, or potent acid inhibitory therapy. The commonest cause of true H. pylori-negative ulcers is usage of nonsteroidal anti-inflammatory drugs, so patients should be carefully questioned about such therapy. Rarer causes of H. pylori-negative duodenal ulcers include gastroduodenal Crohn's disease and Zollinger-Ellison syndrome. About 50% of H. pylori-negative duodenal ulcer patients have no apparent explanation for the ulcer disease. A proportion of these patients have increased gastric acid secretion and increased duodenal acid load, which is likely to be of pathogenic significance. H. pylori-negative ulcers are more difficult to control with antisecretory drugs.