Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Shingles ?
    ### Response:
    Shingles -- also called varicella-zoster -- is a painful skin disease caused by a reactivation of the chickenpox virus. It is distinctive because it affects only one side of the body. The early signs of shingles usually develop in three stages: severe pain or tingling, possibly itchy rash, and blisters that look like chickenpox.
    