Helicobacter pylori Infection does not Protect Against Allergic Diseases: Evidence from a Pediatric Cohort in Northern Sardinia, Italy

Background: A decline in the prevalence of Helicobacter pylori infection has been claimed to increase the probability of developing atopic diseases. Aims: To evaluate the prevalence of atopic disorders in a pediatric population according to seropositivity against H. pylori. Methods: Children referred to the local Pediatric Hospital were investigated to identify risk factors, especially H. pylori infection, associated with atopic disorders. A questionnaire, including demographics, house size, history of breastfeeding, residence, school or daycare center attendance, exposure to animals, and a diagnosis of atopy, was filled out by a trained pediatrician according to parents’ answers. A blood sample was collected from each participant. Results: Seroprevalence of H. pylori infection was 11.7% among 492 children (240 females); 32 of them had a diagnosis of asthma and 12 of allergy. No one child showed both conditions. Statistically significant differences in H. pylori seropositivity were not detected between children with or without atopy (8.4 vs. 12.6; p=0.233). Although atopic disorders were more frequent in children exposed to traditional risk factors none showed to be significant after adjusting for all covariates. Conclusions: H. pylori infection, serologically assessed, was not significantly associated with a reduced risk of atopic diseases in children.