Background: Chronic urticaria is a common disease, though only few data on its natural course are available. In most cases the cause cannot be determined. Recently a relationship of chronic urticaria to infection with Helicobacter pylori (HP) has been postulated, but no controlled study has been performed to prove this association.
Methods: In this prospective study the clinical course and rate of HP infection in 46 patients with chronic 'idiopathic' urticaria were investigated. Infected patients were treated in a double-blind placebo-controlled crossover study with amoxycillin and lansoprazol. Eradication and clinical course were followed up 2 months after each treatment, respectively, 3 and 6 months after the first consultation.
Results: In 19/46 (41%) the chronic 'idiopathic' urticaria resolved within 6 months. 12 patients (24%) were infected with HP, which corresponds to the infection rate of the population at comparable ages without urticaria in Switzerland. Eradication of HP was achieved in 3, but only in 1 was the eradication associated with the resolution of urticaria.
Conclusions: Our data show that in young patients with a rather short history of chronic urticaria frequently a rather favourable natural course of chronic idiopathic urticaria can be seen. No association between HP infection and chronic urticaria could be demonstrated.