What should you know about what causes herpes zoster?

After chickenpox, the varicella-zoster virus can stay inactive in nerve tissue. If it becomes active again, it travels along a nerve and may produce burning, sensitivity, or pain followed by a stripe or patch of blisters, often on one side of the body. The rash pattern and nerve pain help distinguish shingles from many other skin problems, but an examination is still useful.

Someone with shingles can pass the virus to a person who has never had chickenpox or vaccination through contact with fluid from the blisters. That person would develop chickenpox, not shingles.

Contact a GP or clinician promptly when shingles is suspected, particularly when the rash is new. Keep blisters clean and covered, wash hands, and avoid contact with pregnant people, newborns, and people with weakened immunity until lesions have crusted and a clinician gives advice.

Antiviral treatment may be considered after assessment, and timing can affect how useful it is. Do not scratch blisters; use clinician-approved measures for pain or itching.

Seek urgent care for a rash on the forehead, nose, or near an eye; eye pain or vision change; facial weakness; severe headache; confusion; widespread blisters; or severe illness. Prompt advice is also needed during pregnancy or with a weakened immune system.

Ask whether the pattern is shingles, whether antiviral treatment is suitable now, how to manage pain, how long to avoid vulnerable contacts, and whether shingles vaccination is appropriate for your health and age.