LAUSR

Background: Chronic spontaneous urticaria (CSU) is an idiopathic condition that seriously affects quality of life. It is well known that oxidative stress and nitrosative stress (NS) are generally involved in many chronic inflammatory diseases. This study aimed to evaluate the possible role of NS in the pathogenesis of CSU. Methods: Thirty-two children with CSU and 22 healthy control subjects were enrolled in the study. Demographic and clinical features were defined, and disease activity was quantified using the urticaria activity score (UAS). Serum NS was assessed by the plasma levels of total nitric oxide (NOx) metabolites and nitrite and nitrate measurements using a Griess method-based commercial kit. Results: Plasma NOx levels were 82.5 ± 11.3 µmol/L in the CSU group and 50.9 ± 9.4 µmol/L in the control group. The difference was statistically significant (p < 0.001). CSU patients also had higher plasma nitrite levels than controls (53.3 ± 13.8 vs. 30.2 ± 10.1 µmol/L, respectively, p < 0.001). The median values of plasma nitrate were 27.5 µmol/L (IQR 19.1-35.5) in CSU patients and 20.9 µmol/L (IQR 17.9-23.2) in the control group, and the difference was statistically significant (p = 0.009). In addition, plasma NOx and nitrite levels were positively correlated with the UAS (rho = 0.512, p = 0.03 and rho = 0.452, p = 0.011, respectively). Conclusion: Plasma NS is elevated and positively correlated with disease activity in children with CSU.