title: Inverse associations of Helicobacter pylori with asthma and allergy.
abstract: BACKGROUND
  Acquisition of Helicobacter pylori, which predominantly occurs before age 10 years, may reduce risks of asthma and allergy.
  
  
  METHODS
  We evaluated the associations of H pylori status with history of asthma and allergy and with skin sensitization using data from 7663 adults in the Third National Health and Nutrition Examination Survey. Adjusted odds ratios (ORs) for currently and ever having asthma, allergic rhinitis, allergy symptoms in the previous year, and allergen-specific skin sensitization were computed comparing participants seropositive for cagA(-) or cagA(+) strains of H pylori with those without H pylori.
  
  
  RESULTS
  The presence of cagA(+) H pylori strains was inversely related to ever having asthma (OR, 0.79; 95% confidence interval [CI], 0.63-0.99), and the inverse association of cagA positivity with childhood-onset (age </=15 years) asthma was stronger (OR, 0.63; 95% CI, 0.43-0.93) than that with adult-onset asthma (OR, 0.97; 95% CI, 0.72-1.32). Colonization with H pylori, especially with a cagA(+) strain, was inversely associated with currently (OR, 0.77; 95% CI, 0.62-0.96) or ever (OR, 0.77; 95% CI, 0.62-0.94) having a diagnosis of allergic rhinitis, especially for childhood onset (OR, 0.55; 95% CI, 0.37-0.82). Consistent inverse associations were found between H pylori colonization and the presence of allergy symptoms in the previous year and sensitization to pollens and molds.
  
  
  CONCLUSIONS
  These observations support the hypothesis that childhood acquisition of H pylori is associated with reduced risks of asthma and allergy.
authors: Department of Environmental Medicine, New York University School of Medicine, New York, USA.
authors: Yu
authors: Y
authors: Chen
authors: Martin J
authors: MJ
authors: Blaser
mesh_terms: D000328:Adult; D017668:Age of Onset; D001249:Asthma / Q000382:microbiology*; D005260:Female; D016480:Helicobacter pylori / Q000302:isolation & purification*; D006801:Humans; D006967:Hypersensitivity / Q000382:microbiology*; D008297:Male; D008875:Middle Aged; D012221:Rhinitis, Allergic, Perennial / Q000382:microbiology; D012871:Skin Diseases / Q000382:microbiology; D012882:Skin Tests