Post-herpetic neuralgia is a kind of intractable pain that occurs mostly in the elderly. The pain is severe, recurrent, and persistent for many years, and the lack of specific treatments in the past has led to multiple visits to multiple hospitals, making it difficult for patients to obtain good results and even suicidal tendencies in many elderly people. Now let’s first understand what is herpes zoster? Herpes Zoster, commonly known as “snake’s nest”, “snake dan”, “fire dragon wrapped around the waist”, is a common viral skin disease caused by a varicella virus infection. It is a common viral skin disease. The virus invades the sensory endings and then moves and persists in the neurons of the posterior root ganglion of the spinal cord, triggering herpes zoster when the body’s resistance is reduced by colds, malignant tumors, immune diseases, radiation or chemical treatments. The virus enters the body through the respiratory mucosa and spreads through the bloodstream, appearing on the skin as chickenpox, but most people do not develop chickenpox after infection and are recessive infections, becoming viral carriers. The virus is neurophilic, and after invading the sensory nerve endings of the skin, it can move along the nerves to the ganglia of the posterior roots of the spinal cord and latent there. When the host’s cellular immune function is low, such as when suffering from colds, fever, systemic lupus erythematosus and malignant tumors, the virus is activated again, resulting in inflammation and necrosis of the ganglia. Herpes. In rare cases, the herpes virus can spread to the anterior horn cells of the spinal cord and visceral nerve fibers, causing motor nerve palsy, such as ophthalmic and facial nerve palsy, as well as gastrointestinal and urinary tract symptoms. The neuralgia that accompanies this disease mostly disappears spontaneously after the skin lesions heal, but due to poor body resistance, especially in elderly women, who have reduced immunity, aseptic inflammation of the nerves often remains after the skin damage heals, resulting in abnormal impulses issued by the nerves and persistent posterior neuralgia. The most frequently involved nerve is the intercostal nerve, accounting for more than 70% of the total number of cases; the second most frequently involved nerve is the trigeminal nerve, sciatic nerve, and less frequently the cervical nerve, brachial plexus nerve, and pubic nerve. Symptoms: The onset of the disease is preceded by localized burning pain in the skin, accompanied by mild fever, fatigue, weakness and other systemic symptoms. It may be accompanied by symptoms such as runny nose, dry and painful throat, and generalized muscle aches and pains. However, there can be no prodromal symptoms, and after 1 to 3 days, scattered erythema appears on the skin one after another. After 1 to 3 days, scattered erythematous spots appear on the skin. The walls of the blisters are tense and shiny, the water of the blisters is clarified, and there are small depressions on most of the surface of the blisters. Ancillary tests include increased blood sedimentation, higher lymphocyte count, and higher white blood cell count if bacterial infection is combined. After a few days, the blisters become cloudy and purulent, and form a vesicular surface after rupture, and finally dry and crust, leaving temporary erythema after the scabs fall off. The duration of the disease is usually about 2 to 4 weeks. In mild cases, only erythema and papules appear without blisters, which is called incomplete herpes zoster. In malignant lymphoma, acute systemic lupus erythematosus, and the elderly and frail, gangrenous herpes may appear and leave scars after healing, called gangrenous herpes zoster. Herpes zoster can be generalized and is often accompanied by high fever and pneumonia or encephalitis, which can be serious and fatal if not rescued in time, and is called generalized herpes zoster. The distribution of herpes is mostly located on one side, not in a band, and rarely exceeds the midline of the torso, sometimes occasionally exceeding the midline of the torso, due to the nerve endings crossing the midline. The thoracic, cervical and facial trigeminal nerve distribution areas are the preferred sites. Usually, only one branch of the trigeminal nerve is involved. Local lymph nodes are often enlarged and painful. Neuralgia is the main symptom of the disease. The acute stage is due to inflammatory reaction of the ganglion, and the late stage neuralgia is caused by post-inflammatory fibrosis of the ganglion as well as the sensory nerves. Sometimes there is severe neuralgia before the appearance of herpes, when it is often misdiagnosed as acute abdomen or angina pectoris, etc. Elderly patients with frailty or lymphoma often have sequelae of neuralgia, sometimes lasting for months. If herpes occurs in the ophthalmic branch of the trigeminal nerve, conjunctival and corneal herpes can occur, leading to corneal ulceration and blindness, which is a serious complication. When the virus invades the facial and auditory nerves, herpes of the ear shell and external auditory canal occurs, which may be accompanied by deep pain in the ear and with mastoid, tinnitus, deafness, facial nerve palsy and loss of taste sensation in the first 1/3 of the tongue, called herpes zoster facial paralysis syndrome. Very few patients have combined central nervous system damage. Treatment 1. Early antiviral treatment is very important Antiviral drugs include acyclic guanosine, cytarabine and adenosine, among which acyclic guanosine is the most effective. This salt is a competitive inhibitor of guanosine triphosphate, which is also a competitive inhibitor of DNA polymerase. It can terminate the extension of the viral DNA strand and exert a strong inhibitory effect on the activity of the viral DNA polymerase, thus blocking the replication of herpes virus DNA. Acyclic guanosine does not readily enter normal cells. This mechanism indicates that acyclic guanosine is the drug of choice for the treatment of herpes because it is highly effective and has few side effects. Acycloguanosine is indicated for severe patients with generalized herpes zoster or combined with pneumonia or encephalitis. The dose of intravenous drip is 200-250mg, added to 100ml of rehydration solution for 1h, 2-3 times a day for 3-7 days. The oral dose is 200mg, 5 times daily. Although agranuloside and agranulocytoside are effective in antiviral, they are no longer commonly used for herpes diseases since acyclic guanosine is available because they are expensive or have many side effects. Patients with neuralgia can be given analgesic drugs such as aspirin and depot tablets, but the best pain relief should be antiepileptic drugs such as carbamazepine, phenytoin sodium, and gabapentin. Those with severe pain can take prednisone 15-30mg/d orally in the early stage; taper the dosage after 1 week. Early administration of prednisone can eliminate the inflammation of nerve roots. Herpetic neuralgia with prednisone can reduce the fibrosis of the late neuritis, and thus also reduce the pain. In addition, vitamin B1, vitamin B6 or interferon injection can be used. Chinese medicine can be used to clear heat and detoxify the toxins. 2, local skin lesion treatment can not be ignored local skin damage to the rash breakout period, it is extremely easy to combine bacterial infection, therefore, local disinfection, topical antiviral spray, diligent change of medication, keep local clean and dry is very important. Some Chinese herbal medicines are also very effective when applied topically. 3.Local nerve block is one of the most effective treatment methods. As long as there is no obvious local infection, the injection of the identified invading nerve trunk can play the role of pain relief, improving local blood circulation, anti-infection, increasing the healing speed of skin lesions and reducing sequelae. For patients with long history, severe neuralgia, and poor effect of conventional medication, local nerve block therapy can be used, and the drugs used are: local anesthetics, corticosteroids and vitamins. For patients with stubborn pain and little effect on the patient after motor nerve block, nerve destruction injections can be used, such as: intercostal nerve, trigeminal nerve, cervical nerve, etc. However, it must be performed by an experienced pain physician or anesthesiologist, otherwise it can lead to serious consequences.