can begin in the absence of herpes zoster—a condition called zoster sine herpete. There is no treatment that modifies the disease course of PHN; therefore, controlling the affected person's symptoms is the main goal of treatment. Medications applied to the skin such as capsaicin or topical anesthetics (e.g., lidocaine) are used for mild pain and can be used in combination with oral medications for moderate to severe pain. Oral anticonvulsant medications such as gabapentin and pregabalin are also approved for treatment of PHN. Tricyclic antidepressants reduce PHN pain, but their use is limited by side effects. Opioid medications are not generally recommended for treatment except in specific circumstances. Such cases should involve a pain specialist in patient care due to mixed evidence of efficacy and concerns about potential for abuse and addiction. Shingles vaccination is the only way for adults to be protected against both shingles and postherpetic neuralgia, with the vaccine Shingrix providing 90% protection from postherpetic neuralgia. The chickenpox vaccine is approved for infants to prevent chickenpox, which also protects against PHN from a herpes zoster infection. PHN is the most common long-term complication of herpes zoster. The incidence and prevalence of PHN are uncertain due to varying definitions. Approximately 20% of people affected by herpes zoster report pain in the affected area three months after the initial episode of herpes zoster, and 15% of people similarly report this pain two years after the herpes zoster rash. Since herpes zoster occurs due to reactivation of the varicella zoster virus, which is more likely to occur with a weakened immune system, both herpes zoster and PHN occur more often in the elderly. Risk factors for PHN include older age, severe prodrome or rash, severe acute zoster pain, ophthalmic involvement, immunosuppression, and chronic conditions such as diabetes mellitus and lupus. PHN is often very painful and can be quite debilitating. Affected individuals often experience a decrease in their quality of life. Signs and symptoms Symptoms: With resolution of the herpes zoster eruption, pain that continues for three months or more is defined as postherpetic neuralgia. Pain is variable, from discomfort to very severe, and may be described as burning, stabbing, or gnawing. Signs: Area of previous herpes zoster may show evidence of cutaneous scarring. Sensation may be altered over the areas involved, in the form of either hypersensitivity or decreased sensation. In rare cases, the patient might also experience muscle