RESUMEN
BACKGROUND: Chronic spontaneous urticaria (CSU) is a distressing skin disease. Family clustering and heterogeneity in the onset and progression indicate that susceptibility to CSU is a complex trait. In this study, we performed haplotype analysis for one of the key player gene, IL17RA, for CSU to test the association with disease susceptibility and severity. METHODOLOGY: The study included 70 CSU patients and 30 healthy controls. The severity of the disease was evaluated by autologous serum skin test (ASST) and urticaria activity score (UAS). ASST test was done and quality of life was assessed using a questionnaire. Allelic discrimination analysis for rs4819554 and rs879577 was performed using real-time polymerase chain reaction technology. RESULTS: Carriers of rs4819554*G were more prone to develop CSU than its counterpart (P = .039), while rs4819554*A allele displayed more severe phenotype in the form of more prolonged disease duration (P = .040), concurrent angioedema (P < .001), higher level of treatment (P < .001), and higher score of quality of life (P < .001). Additionally, homozygote patients with rs879577*CC were associated with angioedema (P < .001). Haplotype analysis revealed that cohorts with both rs4819554*A and rs879577*T conferred protection against developing CSU (OR = 0.07, 95% CI = 0.01-0.32, P = .001). CONCLUSION: Our results showed that IL17RA gene polymorphisms might contribute to the increased susceptibility to CSU.