Serum IL‐17 levels in patients with rosacea.

Background: Rosacea is a chronic inflammatory skin disease characterized with increased serum and tissue inflammatory mediators. IL‐17 is a well‐known inflammatory mediator that plays important roles in pathogenesis of inflammatory skin diseases. Previous studies reported that Th17 pathway is activated in rosacea and IL‐17, one of Th17 signature cytokines, is elevated in tissue samples of rosacea patients. Objectives: The aim of this study was to investigate serum IL‐17 levels in rosacea patients and to study its relationship with disease characteristics. Methods: Sixty patients diagnosed with rosacea and 60 healthy controls were included in the study. Serum IL‐17 concentrations were measured using enzyme‐linked immunosorbent assay (ELISA). Results: The mean serum IL‐17 level was 8.03 pg/mL (SD = 1.47) in rosacea patients and 7.37 pg/mL (Sd = 1.19) in controls. Serum IL‐17 levels were significantly higher in rosacea (p = 0.002). Serum IL‐17 levels were similar among patients with erythematotelangiectatic (ET) and papulopustular (PP) rosacea (8.02 vs 8.06, p = 0.83). Serum IL‐17 levels did not correlate with rosacea severity (p = 0.59, r = 0.07 in ET rosacea; p = 0.88, r = 0.02 in PP rosacea), age of onset (p = 0.58, r = −0.07), and disease duration (p = 0.37, r = −0.11). Primary features and global assessments did not correlate with serum IL‐17 levels (all p > 0.05). Among secondary features, edema showed a significant negative correlation with serum IL‐17 concentrations (p = 0.037, r = −0.26). Conclusions: Our study showed increased serum IL‐17 levels in rosacea patients and a significant correlation between IL‐17 concentrations and secondary features of the disease suggesting IL‐17 may contribute to pathogenesis of rosacea and may be a new target for rosacea treatment. [ABSTRACT FROM AUTHOR]