<unk> , also known as zoster or 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 mark either on the left or right side 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 though some patients may have fever or headache, or feel tired. 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 (PHN). In those with poor immune function the rash may occur widely. If the rash involves the eye, vision loss may occur.<unk>  and chickenpox are distinct human diseases but are closely related in their life cycles. Both originate from infection of an individual with the varicella zoster virus (VZV). Chickenpox, also called varicella, results from the initial infection with the virus, typically occurring during childhood or adolescence. Once the chickenpox has resolved, the virus can remain inactive (dormant) in human nerve cells (dorsal root ganglia or cranial nerves) for years or decades, after which it may reactivate.<unk>  results when the dormant varicella virus is reactivated. Then the virus travels along nerve bodies to nerve endings in the skin, producing blisters. During an outbreak of<unk> , exposure to the varicella virus found in<unk>  blisters can cause chickenpox in someone who has not yet had chickenpox; this initial infection will not trigger<unk> , however. How the virus remains dormant in the body or subsequently re-activates is not well understood. Risk factors for reactivation of the dormant virus include old age, poor immune function, and having contracted chickenpox before 18 months of age. Diagnosis is typically based on the signs and symptoms presented. Varicella zoster virus is not the same as herpes simplex virus, although both belong to the same family of herpesviruses.<unk>  vaccines reduce the risk of<unk>  by 50% to 90%, depending on the vaccine used. It also decreases rates of postherpetic neuralgia, and, if<unk>  occurs, its severity. If<unk>  develops, antiviral medications such as aciclovir can reduce the severity and duration of disease if started within 72 hours of the appearance of the rash. Evidence does not show a significant effect of antivirals or steroids on rates of postherpetic neuralgia. Paracetamol, NSAIDs, or opioids may be used to help with acute pain. It is estimated that about a third of people develop<unk>  at some point in their lives. While<unk>  is more common among older people, children may also get the disease. The number of new cases per year ranges from 1.2 to 3.4 per 1,000 person-years among healthy individuals to 3.9 to 11.8 per 1,000 person-years among those older than 65 years of age. About half of those living to age 85 will have at least one attack, and fewer than 5% will have more than one attack. Although symptoms can be severe, risk of death is very low: 0.28 to 0.69 deaths per million. The disease has been recognized since ancient times.
Shingles
Insect bites and stings
Sealpox
Angina
Farmyard pox
Herpes simplex
Streptococcal intertrigo
Sciatica