title: Pseudoallergic reactions in chronic urticaria are associated with altered gastroduodenal permeability.
abstract: BACKGROUND
  In a subgroup of patients with chronic urticaria (CU) the disease is caused by pseudoallergic reactions to food. The aim of this study was to investigate whether disturbances of the gastrointestinal barrier function play a role in the pathomechanism of the disease.
  
  
  METHODS
  In 55 patients with CU gastrointestinal permeability was measured with an in vivo triple-sugar-test before and after 24 days of a diet low in pseudoallergens. Sucrose served as marker for gastroduodenal permeability, lactulose/mannitol ratio for intestinal permeability.
  
  
  RESULTS
  Basal gastroduodenal and intestinal permeability were significantly higher in patients with urticaria as compared to controls. In 29 of the 55 patients skin symptoms decreased or completely disappeared during the diet (responders). Compared to nonresponders (n = 26), responders had a significantly higher gastroduodenal permeability before treatment (0.36 +/- 0.04 vs 0.15 +/- 0.01% sucrose; P < 0.001), which decreased after the diet (0.17 +/- 0.02; P < 0.001). The number of patients with Helicobacter pylori infections did not differ between the two groups.
  
  
  CONCLUSIONS
  The results indicate that in a subgroup of patients with CU and pseudoallergy an impaired gastroduodenal barrier function may be of pathophysiological importance. The underlying mechanisms seem to be independent of H. pylori infection.
authors.affiliation: Department of Gastroenterology, Hepatology, and Endocrinology, Charité Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Buhner
authors.forename: I
authors.initials: I
authors.lastname: Reese
authors.forename: F
authors.initials: F
authors.lastname: Kuehl
authors.forename: H
authors.initials: H
authors.lastname: Lochs
authors.forename: T
authors.initials: T
authors.lastname: Zuberbier
mesh_terms: D000328:Adult; D002908:Chronic Disease; D004386:Duodenum; D005260:Female; D005512:Food Hypersensitivity / Q000276:immunology / Q000503:physiopathology*; D005753:Gastric Mucosa / Q000378:metabolism*; D006801:Humans; D007408:Intestinal Absorption / Q000276:immunology / Q000502:physiology*; D007413:Intestinal Mucosa / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D010539:Permeability; D013270:Stomach; D014581:Urticaria / Q000276:immunology / Q000503:physiopathology*