Post Herpetic Neuralgia
Post-herpetic neuralgia occurs when the pain associated with shingles becomes chronic. Definitions of post-herpetic neuralgia differ in terms of the time of onset and duration of pain, and this has resulted in difficulty estimating the prevalence of the disease. One source estimates that approximately 20% of people older than 50 years will develop post-herpetic neuralgia, despite antiviral treatment beginning within 72 hours of rash onset.
Post-herpetic neuralgia is the most common complication of shingles in adults; it is uncommon in children. In UK primary care, the incidence of post-herpetic neuralgia is estimated to be 28 per 100,000 person-years.