Helicobacter pylori infection in patients with chronic urticaria: correlation with pathologic findings in gastric biopsies.

Background: Chronic urticaria is a persistent urticaria lasting longer than 6 weeks, affecting 20% of the general population. Various infectious agents have been reported as causes of urticaria, including Helicobacter pylori, which is a common worldwide bacterial infection. Its role in inducing allergic conditions, such as chronic urticaria, has been suggested in some reports and ignored in others.

Aims: To assess the prevalence of H. pylori infection in patients with chronic urticaria and to explore the possible etiopathogenetic link between them.

Methods: Thirty-five patients suffering from chronic urticaria and 10 normal control individuals were subjected to upper endoscopic gastric biopsies to assess and semiquantify H. pylori infection and to address other pathologic abnormalities, using routine hematoxylin and eosin staining and Giemsa staining.

Results: Forty percent of control subjects and 57% of patients were positive for H. pylori infection, but the difference did not reach statistically significant levels (P = 0.47). The severity of urticarial symptoms was greater in the H. pylori-positive than in the H. pylori-negative group (P = 0.019). Heavy bacterial colonization (P = 0.008) and intense gastric inflammation (P < 0.0001) were associated significantly with severe clinical manifestations. Eighty percent of the H. pylori-positive urticaria group experienced complete remission after receiving eradication therapy for H. pylori.

Conclusions: Helicobacter pylori may have a role in the exacerbation of urticarial symptoms, even though it is not involved directly in its etiology, and its eradication may lead to symptom improvement in a considerable number of infected urticaria patients. The severity of symptoms is dependent on the density of bacterial infection and the intensity of inflammatory infiltrate in the gastric biopsy.