RESUMEN
Fifty postherpetic neuralgia (PHN) patients with a course ≥3 years and the Pain Numeric Rating scale (NRS)≥5 were included in the analysis.All patients were treated with nerve block and subcutaneous injection in the affected area.The paravertebral nerve blocks were performed by injecting 5 ml lidocaine in the concentrations of 0.3％;the concentration of lidocaine for branch blockage and peripheral nerves was 1.0％,and that for subcutaneous injection was 0.3％,respectively;2 mg dexamethasone and 0.5 mg vitamin B12 were added in the injections.The NRS scores and quality of life scores were documented before and after the treatment.The NRS score was significantly decreased at different time points of treatment (F=279.6,P＜0.01).At the end of the treatment and at 1 month,3months,6months of follow-up,the scores were significantly lower than those before the treatment.All patients showed enormous improvement in the quality of life at 1,3 and 6 months after treatment.The pain relief was "excellent" or "good" in 38 cases.The efficacy of treatment is associated with skin scar and allodynia.The study indicates that nerve block and subcutaneous injection has a satisfactory efficacy in treatment of chronic postherpetic neuralgia.