Helicobacter pylori, gastritis, and ulcers in pediatrics.

Hp now appears to be more than a simple commensal organism in patients with gastritis or peptic ulcer disease. Microbiologic, serologic, and epidemiologic studies all confirm that Hp has an important role in children with abdominal pain. Hp is found in the gastric mucosa of children with histologically proven gastritis or peptic ulcer. The organism can be transmitted from human to human with evidence of colonization, appearance of gastritis, and serum antibody response. Antimicrobial therapy directed at Hp eradicates colonization and resolves symptoms. Hp antibodies appear more frequently in familial clusters and the frequency of antibody positivity increases with age. Children are more likely to have symptomatic disease associated with elevated antibody titers. Recurrence of disease is associated with reappearance of the organism. At the present time, colonization can be detected only by gastric biopsy; however, it may be possible eventually to diagnose or follow infections by obtaining serum antibody titers or urea breath-testing. The natural history of Hp infection is unclear. Although it can cause an acute gastritis, it generally is found in association with chronic gastritis. The increase in seropositivity with age may mean that slow changes evolve over decades or that age cohorts have been infected differentially. How does antral colonization with Hp cause duodenal ulceration? The organism is not found in the duodenum and most patients with gastritis do not develop ulcers. This may be related to changes in acid production and mucosal protection associated with Hp colonization, but few studies have been done. What factors initiate Hp infection? Both volunteers who became colonized first suppressed acid secretion with H2-antagonists. Hypochlorhydria also seems to follow Hp infection in these same studies. The role of diet and drugs, or other environmental and genetic factors, in initiating infection is largely unexplored. An effective means of therapy needs to be developed. Although Hp appears sensitive in vitro to many compounds, it is difficult to eradicate in vivo, especially with monotherapy. Single-drug therapy suppresses the organism, but recurrence rates are high. It is difficult to deliver effective doses of drugs to the mucous niche the organism has selected and concerns about long-term therapy and its side effects persist. Current data suggest no ready solution to the initial case presentation. A child with primary gastritis or duodenal ulcer should be treated first with standard antacid and H2-receptor antagonist therapy. If endoscopy is performed, biopsies of normal-appearing areas of gastric antrum should be stained for Hp and a biopsy urease test should be performed.(ABSTRACT TRUNCATED AT 400 WORDS)