There are many causes of blisters on the back, such as herpes zoster, atopic dermatitis, herpetic pemphigoid, and chickenpox. 1. Herpes zoster: Infection by varicella-zoster virus causes blisters on the back, which may appear as clustered blisters distributed unilaterally, usually not exceeding the midline. 2. Contact dermatitis: skin contact with allergic substances may cause blisters on the back, usually the liquid in the blisters is clearer, accompanied by different degrees of itching. 3. Herpetic pemphigoid: Herpetic pemphigoid can lead to blisters on the back, the cause of the disease is not yet clear, may have a certain relationship with autoimmunity. 4. Chickenpox: Infection with varicella zoster virus can lead to the phenomenon of blisters on the back, may have fever, headache and other systemic symptoms. There are many reasons for blisters on the back, after the symptoms, it is recommended to go to the hospital in a timely manner to improve the examination, follow the doctor’s instructions to take standardized treatment, do not ignore the symptoms, take it lightly.