Postherpetic Neuralgia

Postherpetic neuralgia (PHN) occurs when the varicella-zoster virus (VZV) directly destroys ganglion cells. When the virus is activated in the dorsal root ganglia of the spinal cord or cranial ganglia, the nerve myelin sheath and axon are damaged, and these damaged peripheral nerves continuously transmit abnormal excitation signals to the central nervous system. As a result, even after the skin rash has healed, burning, electric shock-like, and tingling abnormal sensations remain. Advanced age, immunosuppression, and the severity of the initial rash and pain are major risk factors for PHN. In Korean medicine, herpes zoster is viewed as a heat toxin syndrome where dampness and heat toxins invade the liver meridian. It is explained that if residual heat from toxins remains in the meridians after onset and blocks the circulation of Qi and blood, the Qi and blood clot and stagnate, leading to chronic neuralgia. Since the liver governs muscle and nerve pathways, damage to the liver meridian causes persistent pain throughout the entire muscle and nerve pathway of the corresponding skin segment. Dongjedang approaches treatment by removing remaining heat toxins and cloted Qi and blood to restore circulation. We fundamentally address the cause of pain by regulating abnormal excitation signals along the damaged nerve pathways through acupuncture and pharmacopuncture.