Etiologic aspects and prognostic factors of patients with chronic urticaria: nonrandomized, prospective, descriptive study.

BACKGROUND: Studies investigating etiologic factors in chronic urticaria are based on small populations of a few hundred patients. In addition, data on prognostic factors of the disorder are scarce.
OBJECTIVE: To investigate the etiologic and prognostic factors of chronic urticaria on a large population referred to tertiary specialized hospital departments.
METHODS: The study investigated 2,523 patients with chronic urticaria and a negative autologous serum skin test using anamnesis, and the literature suggested laboratory tests for etiologic factors of the disorder. The patients were prescribed cetirizine 10 mg daily plus treatment of any underlying disorders illuminated by the laboratory investigation. The rescue medicine was loratadine 10 mg. The patients were evaluated every 3 months. Comparative statistical methods were used to evaluate the prognostic factors having an impact on the duration of the disorder until resolution of symptoms.
RESULTS: Etiologic factors of chronic urticaria-angioedema were identified in 38.7% of the patients. Physical urticarias had a prevalence of 17.1% in the population under study. Other common etiologic factors identified included infection (7.7%) and autoimmune thyropathy (7.3%). Multiple regression analysis showed that female gender, long duration of the disorder at the initial examination, the presence of angioedema, and physical urticarias are associated with worse prognosis of the disorder, whereas increased self-reported stress and psychiatric disease had no impact on the course of the disorder.
CONCLUSION: A detailed medical history and selective laboratory tests can illuminate etiologic factors in less than 40% of patients with chronic urticaria. Prognostic factors identified to impact the natural history of the disorder could be helpful when designing studies assessing the efficacy of therapeutic agents for chronic urticaria.