Comparison of Clinical Characteristics and Prognosis of Chronic Urticaria according to the Aspirin Sensitivity

Abstract

Background: The pathogenic mechanism of chronic urticaria and its prognosis are still unknown. One third of chronic urticaria patients have been associated with aspirin sensitivity. To investigate the prevalence of aspirin sensitivity in chronic urticaria patients and to compare the clinical features and prognosis between aspirin-sensitive and non-sensitive groups. Methods: The 227 patients with chronic urticaria diagnosed by the presence of hives for more than 6 months were enrolled and classified into two groups according to aspirin sensitivity which was confirmed by the oral challenge test. ANA and IgG antibody to Helicobacter pylori were measured by ELISA. Anti-thyroid and total IgE antibodies were detected by radioimmunoassay (RIA). Atopy was determined by a positive skin test to at least one common inhalant allergen. In 178 of all patients whose follow-up duration was longer than 1 year, drug requirements for antihistamines and steroids were calculated and compared between the two groups. Results: The 81 (35.7%) of 227 patients with chronic urticaria showed positive results in the aspirin oral challenge test. The patients with aspirin sensitivity were younger and had higher atopic tendency than those without aspirin sensitivity (34.7+/-11.4 vs 39.4+/-11.7 years, 76.5% vs 58.6%, P<.005, respectively). No significant difference was noted in prevalences of ANA, anti-thyroid antibodies, and IgG antibody to H. pylori between the two groups. On the remission rates of urticarial symptoms during 6 months and 1 year follow-up periods, no significant difference was noted (54.5 vs 50.0% and 65.1 vs 72.3%, P>.05, respectively). The drug requirements for systemic steroids (5.86+/-7.3 vs 2.75+/-4.1 prednisolone equivalent mg/week, P=.001) were significantly higher in patients with aspirin sensitivity. There were no significant differences in requirements for H1 receptor antagonists (23.54+/-42.2 vs 23.49+/-60.0 loratadine equivalent mg/week) and H2 receptor antagonists (156.05+/-141.3 vs 134.55+/-116.3 cimetidine equivalent mg/week) between the two groups. Conclusion: Aspirin sensitivity was noted in 35.7% of chronic urticaria patients. The patients with aspirin sensitivity have higher atopic tendency, younger age and require more systemic steroids to control urticaria symptoms.