Shingles Disease

帶狀皰疹是一種病毒性疾病，其特徵在於一個痛苦的皮疹。

Shingles, also known as herpes zoster, is a viral disease characterized by a painful skin rash with blisters in a localized area. Typically the rash occurs in a single, wide stripe either on the left or right of the body or face. Two to four days before the rash occurs there may be tingling or local pain in the area. Otherwise there are typically few symptoms. The rash usually heals within two to four weeks; however, some people develop ongoing nerve pain which can last for months or years, a condition called postherpetic neuralgia. In those with poor immune function the rash may occur widely. If the rash involves the eye, vision loss may occur. Shingles is due to a reactivation of varicella zoster virus (VZV) within a person's body. The disease chickenpox is caused by the initial infection with VZV. Once chickenpox has resolved, the virus may remain inactive in nerve cells. When it reactivates, it travels from the nerve body to the endings in the skin, producing blisters. Risk factors for reactivation include old age, poor immune function, and having had chickenpox before 18 months of age. How the virus remains in the body or subsequently re-activates is not well understood. Exposure to the virus in the blisters can cause chickenpox in someone who has not had it before, but will not trigger shingles. Diagnosis is typically based on a person's signs and symptoms. Varicella zoster virus is not the same as herpes simplex virus; however, they belong to the same family of viruses.