During an outbreak of shingles, exposure to the varicella virus found in shingles blisters can cause chickenpox in someone who has not yet had chickenpox; this initial infection will not trigger shingles, 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 they belong to the same family of herpesviruses.Shingles vaccines reduce the risk of shingles by 50% to 90%, depending on the vaccine used. Vaccination also decreases rates of postherpetic neuralgia, and, if shingles occurs, its severity. If shingles 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 shingles at some point in their lives. While shingles is more common among older people, children may also get the disease. According to the US National Institutes of Health, 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.
For this reason, knowledge of these herpes virus conditions was limited to severe cases. DNA techniques have made it possible to diagnose "mild" cases, caused by VZV or HSV, in which the symptoms include fever, headache, and altered mental status. Mortality rates in treated people are decreasing. References
Further reading
Saguil A (November 2017). "Herpes Zoster and Postherpetic Neuralgia: Prevention and Management". American Family Physician. 96 (10): 656–663. PMID 29431387. External links

NINDS Shingles Information Page, National Institute of Neurological Disorders and Stroke