There are many reasons for herpes on the back, such as contact dermatitis and viral infection. 1. Contact dermatitis: the skin on the back comes into contact with certain irritating objects, which may lead to the formation of localized blisters and induce contact dermatitis. The main feature of this disease is that large blisters may appear at the location of the skin in contact with the skin, thus letting people mistakenly think that it is herpes, which is accompanied by itching at the same time. 2. viral infection: most back herpes is due to viral infection, the most common is herpes zoster. Herpes zoster is a skin disease caused by the varicella zoster virus, which can cause herpes on the back, and may also be accompanied by localized skin tingling and burning sensations. There are many causes of herpes on the back, it is recommended to go to the hospital as soon as possible after the appearance of symptoms to improve the examination, a clear diagnosis, diagnosed and given standardized treatment.