Shingles

Shingles is what happens when the chickenpox virus wakes up. After chickenpox, the varicella zoster virus does not leave the body; it settles in nerve roots and stays there, usually for decades. Shingles is that virus becoming active again in one nerve, producing pain and a rash in the strip of skin that nerve supplies.

Roughly one person in four has it at some point. It becomes commoner and more severe with age, and more likely where the immune system is suppressed by illness or treatment.

One correction first, because it is widely stated the other way round and it matters. Shingles cannot develop in someone who has never had chickenpox. No chickenpox means no dormant virus to reactivate. Someone who has never had it and comes into contact with shingles will catch chickenpox, not shingles.

What it looks and feels like

The pain usually arrives first. For somewhere between a day and a week before anything is visible, there is burning, stabbing, itching or unusual sensitivity in a band on one side of the body — often mistaken for a pulled muscle, or for something internal depending on where it falls.

Then the rash. The pattern is the most recognisable thing about shingles:

• One side only, in a band, and it does not cross the middle of the body. Most often around the ribs or waist, but it can appear on the face, neck, limbs or buttocks.
• Blisters that fill with fluid over a few days, then burst and crust over.
• Two to four weeks from start to healed skin, sometimes leaving pale marks or scarring.

Fever, headache and feeling generally unwell are common alongside it. Occasionally the pain comes with no rash at all, which is genuinely hard to identify.

The thing that matters most

Antiviral tablets work best when started within seventy-two hours of the rash appearing. They shorten the episode, reduce the severity, and — the important part — reduce the chance of being left with long-term nerve pain afterwards.

That makes the trigger for seeking help the appearance of the rash, not the pain becoming unbearable. Advice to wait until it is intolerable before seeing anyone has the timing exactly backwards, because by then the window in which treatment does most good has closed. A same-day or next-day appointment, or NHS 111 out of hours, is the right response to a new one-sided blistering rash with pain.

Antivirals may still be given later than three days where the rash is still forming, where there are complications, or where someone is older or immunosuppressed.

Pain relief

Paracetamol and ibuprofen for ordinary pain. Shingles pain is often nerve pain rather than ordinary pain, and when it is, those do comparatively little — the medicines that help are the ones used for neuropathic pain, such as amitriptyline, gabapentin or pregabalin, which need prescribing and take time to work.

Beyond that: keep the rash clean, loose clothing over it, a cool compress rather than heat. Calamine lotion soothes the itch, which is worth having, though it does not make anything heal faster. Not scratching matters, because broken blisters can become infected.

When it needs seeing urgently

Most shingles is unpleasant rather than dangerous. These are the exceptions:

• A rash on the forehead, around the eye, or on the tip or side of the nose. This carries a real risk of eye involvement, which can threaten sight. Same-day assessment, and an eye specialist if the eye itself is red, painful or vision has changed.
• Weakness of one side of the face, hearing loss, ringing, vertigo, or a rash in or around the ear. This combination has its own name and needs same-day treatment to give the facial nerve the best chance of recovering.
• A rash that is spreading widely beyond one band, or anyone who is confused, very unwell, or has a severe headache with a stiff neck.
• Anyone whose immune system is suppressed — by chemotherapy, high-dose steroids, immunosuppressant drugs or a condition affecting immunity — should be assessed promptly whatever the rash looks like.
• A rash in a child, or in pregnancy, is worth a call rather than a wait.

Pain that outlasts the rash

Post-herpetic neuralgia is nerve pain that persists after the skin has healed. It is the commonest complication and the reason early treatment is worth chasing: it becomes substantially more likely with increasing age, and it can last months, occasionally much longer.

It is described as burning, aching or stabbing, often with skin so sensitive that clothing hurts. It is treated as neuropathic pain, with the medicines named above, sometimes with topical lidocaine or capsaicin, and a pain clinic where it is severe. It is not a sign that the shingles is still active, and it is not something to be endured quietly — it responds to treatment, and the treatments are different from ordinary painkillers.

Two other complications worth naming accurately. Cellulitis is a bacterial infection of the skin and the tissue beneath it, not an inflammation "within the cells"; it makes an area hot, red, swollen and tender, spreads, and needs antibiotics promptly. And shingles can leave scarring or lasting changes in skin colour where the blisters were.

Passing it on, which works differently from how it is usually described

This is the part most often got wrong, so plainly:

• Shingles is not caught from anyone. It comes from a virus already present in the body.
• Contact with the fluid in the blisters can give chickenpox to someone who has never had chickenpox and has not been vaccinated. They get chickenpox, not shingles.
• It is not airborne in the way chickenpox is, as long as the rash is localised and can be covered. Being in the same room is not the risk; touching the blisters, or something freshly contaminated by them, is.
• The infectious period runs until the blisters have dried and crusted, which is usually a week or so.
• A rash with no blisters, or one that has crusted, is not infectious. The claim that someone with no visible rash passes it on more readily is the reverse of the truth — no blisters means no fluid to transmit.

While the rash is weeping, it is worth keeping it covered and avoiding newborn babies, anyone pregnant who has not had chickenpox, and anyone immunosuppressed. Work and school are generally fine with the rash covered.

On pregnancy, the risk is specific rather than general. Someone pregnant who has already had chickenpox is immune, and shingles in a contact poses no risk to the baby. Someone pregnant who has not had chickenpox and is exposed to shingles blisters could catch chickenpox, which can be serious in pregnancy — and that is a reason to seek advice promptly rather than to worry generally. Anyone pregnant who is unsure whether they have had chickenpox can have their immunity checked.

The vaccine, which is free and widely missed

There is an NHS shingles vaccination programme, and for anyone approaching the eligible ages it is probably the most useful thing here. It reduces the chance of getting shingles and, in those who still get it, reduces the chance of lasting nerve pain.

The programme changed on 1 September 2023. The vaccine used is Shingrix, given as two doses — generally six to twelve months apart, or between eight weeks and six months apart for people who are immunosuppressed. Anyone who had the older single-dose vaccine previously does not need it again.

Eligibility now begins on turning 65 rather than at a single fixed age, with a rolling programme for people in their seventies, and from age 50 for anyone severely immunosuppressed. The lower age threshold is being brought down in stages over the course of about a decade, so the exact cohorts shift from year to year.

The practical version: a GP practice should get in touch when someone becomes eligible, but this does not always happen, and asking at the surgery is worthwhile for anyone over 50 who is immunosuppressed or anyone over 65 who has not been offered it.

Three things that are commonly believed and are not so

Shingles is not caused by stress. Stress and illness may make reactivation more likely, but the cause is the virus and the main driver is the immune system changing with age.

It can happen more than once. Having had shingles does not confer immunity to a further episode, which is part of the argument for vaccination even after an episode.

It has nothing to do with genital herpes. The confusion comes from the name — shingles is caused by herpes zoster, which belongs to the same broad family of viruses as herpes simplex but is a different virus causing a different illness, transmitted differently.