Objective To analyze the correlation between herpes zoster neuralgia and the methylation status of the whole genome and GCH1 gene.Methods From June to October in 2017,patients with confirmed herpes zoster and obvious neuralgia were selected in Department of Dermatology,The Affiliated Hospital of Xuzhou Medical University,who achieved complete remission (no effect was observed on normal sleep) of neuralgia after antiviral and neurotrophic treatment.Finally,36 patients and 36 healthy controls were enrolled into this study.Peripheral blood samples were obtained from the healthy controls and patients before and after the treatment.Dot-blot hybridization assay was performed to determine the methylation status of the whole genome,methylated-DNA IP kit was used to enrich the methylation sites of the GCH1 gene,and real-time quantitative PCR was conducted to detect changes in methylation status of the GCH1 gene.Statistical analysis was carried out with GraphPad Prism v7.00 software by using paired t test for the comparison of methylation status before and after the treatment,and two-sample t test for the comparison between the patient group and control group.Results The relative methylation level of the whole genome was 135.94 ± 2.52 in the patients before treatment,significantly lower than that in the patients after treatment (144.76 ± 3.48,t =2.056,P ＜ 0.05) and healthy control group (146.84 ± 3.39,t =2.580,P ＜ 0.05).However,there was no significant difference in the methylation status of the whole genome between the patients after treatment and healthy controls (t =0.429,P ＞ 0.05).Compared with the patients after treatment (0.89 ± 0.13) and healthy control group (0.97 ± 0.07),the methylation status of the GCH1 gene significantly decreased in the patients before treatment (0.65 ± 0.17;t =3.977,4.648 respectively,P ＜ 0.05,＜ 0.01 respectively),while no significant difference between the patients after treatment and the healthy controls (t =0.506,P ＞ 0.05).Conclusion The methylation status of the whole genome and GCH 1 gene markedly decreased in the patients with herpes zoster neuralgia.