Evaluation of etiological factors in patients with chronic urticaria.

In the last few decades, increasing understanding of the pathomechanisms involved in chronic urticaria has highlighted the heterogeneity of different subtypes, and chronic urticaria is now classified as chronic spontaneous urticaria and inducible urticaria. Although many factors are thought to be involved in chronic urticaria, the etiology is yet to be clarified. The purpose of this study was to investigate etiological factors in patients with chronic urticaria. Five hundred patients with chronic urticaria, 351 women and 149 men, were studied for etiological factors. The autologous serum skin test was performed on 197 patients. Provocation testing for physical urticaria was performed on 354 patients. Patients with acute urticaria were excluded from the study. We determined at least one focus of infection that might be involved in the etiology of the disease in 18.8% of cases. Patients with infections were treated, and symptoms resolved after treatment in six cases (5.3%). Autologous serum skin tests were positive in 125 patients (63.5%). Provocation tests for physical urticaria were positive in 131 (37%) patients with urticaria. We suggest that physical stimuli and autoantibodies play an important role in the etiopathogenesis of urticaria.