The Analgesic Effect of Electroacupuncture on Postherpetic Neuralgia

Inclusion Criteria: * Patients who meet the diagnostic criteria for postherpetic neuralgia (with a clear history of acute herpes zoster, and the duration of postherpetic pain exceeds 90 days) * Aged 45 to 75 years old * Patients who were diagnosed with moderate or above pain during the observation period (the daily pain score was continuously collected within 7 days during the observation period, and the average NRS-11 pain score was \>=4) * Subjects who did not participate in other ongoing clinical studies * Sign informed consent and volunteer to participate in the study Exclusion Criteria: * Patients who are currently receiving or receiving more than one of the "permitted combinations" or any "prohibited combination and treatment" for PHN listed in the following part at least 14 days before screening, and are unwilling to undergo washout period, or patients with serious safety problems during washout period or observation period * Patients who are expected to receive any new prescription drug or other treatment for PHN after the start of the trial * Patients with serious uncontrolled medical conditions, such as cardiovascular, lung, liver, kidney, gastrointestinal tract, metabolism, endocrine, nervous system, respiratory system, urogenital system and other serious diseases, or systemic organ dysfunction, malignant tumor, hematologic disease such as bleeding tendency or coagulation dysfunction, serious mental illness such as depression or schizophrenia Symptoms, hepatitis B antigen or hepatitis C antibody positive known state or history of immune dysfunction, history of HIV infection, etc. * Patients with severe pain unrelated to PHN, such as after surgery for clinical major diseases * Patients with PHN who have received nerve intervention or other neurosurgical treatment, such as selective nerve damage, percutaneous radiofrequency thermocoagulation or pulsed nerve modulation technology, etc. * Patients with some special types of herpes zoster, such as those with meninges, cornea, conjunctiva, ear involvement, visceral herpes zoster, generalized herpes zoster * Patients with skin ulceration, new herpes, or skin infection * Patients with cardiac pacemaker, metal allergy or severe fear of needle * Patients who are unable to give full informed consent or cannot cooperate with pain scale assessment due to mental, mental, linguistic or behavioral disorders * Patients who have poor compliance or are prone to fall off due to other reasons, such as the current residence is not in the city where the recruitment hospital is located, or the working environment changes frequently * Pregnant and lactating women