Herpes zoster, also known as shingles, is a viral infection caused by the reactivation of the varicella-zoster virus (VZV), the same virus responsible for chickenpox. After someone recovers from chickenpox, the virus remains dormant in the body's nerve tissues and can reactivate years later as shingles. Key Points: Symptoms: Pain: Often the first symptom, typically a burning or tingling sensation in a localized area. Rash: A red, blistering rash usually appears a few days after the pain begins. It typically affects one side of the body, often in a band-like distribution (dermatome). Fever, fatigue, and headache: These may accompany the rash. Postherpetic Neuralgia (PHN): A common complication, causing ongoing pain in the affected area even after the rash resolves. Risk Factors: Age: Most common in people over 50, though it can occur at any age. Weakened immune system: Conditions like HIV, cancer, or immunosuppressive treatments (e.g., chemotherapy, steroids) can increase risk. History of chickenpox: Since the virus remains dormant in the body after chickenpox, anyone who has had chickenpox is at risk. Transmission: Direct contact with the fluid from the blisters can spread the virus to someone who hasn't had chickenpox or the vaccine, potentially causing chickenpox in that person. Shingles itself is not contagious. Prevention: Vaccination: The shingles vaccine (e.g., Shingrix) is recommended for adults 50 and older to reduce the risk of developing shingles and its complications, including PHN. Treatment: Antiviral medications (e.g., acyclovir, valacyclovir, famciclovir) can help shorten the duration of the infection and reduce the severity of symptoms, especially if started early. Pain relief: Analgesics, corticosteroids, and other pain management strategies may be used, particularly if postherpetic neuralgia develops. Complications: Postherpetic neuralgia (PHN): Persistent pain in the affected area, often the most troubling long-term effect. Vision loss: If the rash affects the eye (ophthalmic zoster), it can lead to serious eye problems, including blindness. Neurological issues: Rarely, shingles can lead to encephalitis, meningitis, or other neurological complications. If you suspect you have shingles, it's important to see a healthcare provider, as early treatment can reduce the severity and duration of the illness.