Shingles is caused by the Herpes virus. The virus enters the nervous system and resides in the sensory nerve ganglia throughout the body's life. When conditions are favorable (weakened immune system, acute and chronic infections, poisoning, stress...), the virus reactivates, destroying the A-alpha sensory nerve fibers under the skin, causing pain to appear. Until now, this post-herpetic neuralgia is still a great difficulty and challenge for treatment.