What causes varicella virus infection?

Varicella-zoster virus belongs to a group of viruses that can stay in nerve tissue after the first illness. The initial infection produces chickenpox, often with an itchy blistering rash and fever. After recovery, the virus may remain inactive for a long time. Reactivation affects a nerve pathway and produces shingles, usually as a painful, one-sided rash. Having a rash does not by itself confirm which condition is present, so the pattern, timing and examination matter.

Avoid scratching blisters, keep the skin clean, and wash your hands after touching a rash. Do not share towels or clothing while new blisters are appearing. Arrange a GP Consultation if you are unsure whether the rash is chickenpox or shingles, especially if symptoms began recently, because an assessment can guide whether Antiviral Treatment is appropriate. A clinician can also discuss Chickenpox Vaccination for prevention when it fits your health history.

Seek prompt medical advice for a new blistering rash during pregnancy, in a baby, or in someone with a weakened immune system. Contact a clinician urgently if the rash involves an eye, breathing is difficult, confusion develops, or the person cannot keep fluids down. Fever with a rapidly worsening rash also warrants assessment; see Fever for related guidance.

Ask whether the rash pattern fits chickenpox or shingles, whether anyone at home should avoid contact, and which medicines are suitable for itch or pain. You can also ask when normal activities are safe and whether vaccination is relevant.