Herpes zoster is sometimes an invisible infection, and snakebite can have a distinct distribution of banded erythema and blisters on the skin surface. If a patient with shingles experiences discomfort and burning sensation, but the skin surface is not different, it may be an invisible infection of shingles, which usually occurs when the immune system is better. If there is an invisible infection, most patients do not care and do not go to the hospital for examination, so many patients are not aware that it is shingles after the onset of the disease. Some patients may go to the hospital for examination, mainly by culturing local cells, doing cellular virus culture, and detecting the virus to confirm the diagnosis later. Local cell DNA can also be taken for laboratory amplification to detect viral DNA for diagnosis.