Shingles (Herpes Zoster)

What causes shingles

After chickenpox, the varicella-zoster virus does not leave the body. It travels up sensory nerves and lies dormant in nerve root clusters (ganglia) near the spinal cord and brain for decades. When immune control weakens, often with age, it reactivates. The virus travels back down one nerve to the skin, inflaming the nerve and producing a rash in that nerve's strip of skin, called a dermatome.

Anyone who has had chickenpox, or rarely the live chickenpox vaccine, can get shingles. You cannot catch shingles from someone else.

Risk factors

• Age over 50, with risk rising each decade
• A weakened immune system: cancer, especially blood cancers, chemotherapy, HIV, organ transplant, high-dose steroids and other immune-suppressing medicines (including JAK inhibitors)
• Diabetes, chronic kidney disease, lung disease and autoimmune conditions
• Physical or emotional stress
• Having had chickenpox in the first year of life

Early signs of shingles

The first symptoms appear 1 to 5 days before the rash (the prodrome):

• burning, tingling, itching, aching or stabbing pain in one area on one side of the body
• skin that is unusually sensitive to touch or clothing
• headache, tiredness, feeling unwell and sometimes a mild fever

Before the rash appears, shingles pain is often mistaken for a heart problem, kidney stone, pulled muscle or gallbladder disease, depending on where it is.

Shingles symptoms and stages

1. Prodrome (days -5 to 0): pain, tingling or itching in one area.
2. Rash (days 1 to 5): red patches appear, followed quickly by clusters of small fluid-filled blisters on a red base, in a band or strip on one side. The rash does not usually cross the midline of the body.
3. Blisters (days 3 to 10): new blisters stop forming within about a week. They may cloud over and break.
4. Crusting (days 7 to 14): blisters dry and scab.
5. Healing (weeks 2 to 4): scabs fall off. The skin may be left paler or darker, and occasionally scarred.

Where shingles appears

• Chest and back (most common): a band wrapping around one side of the trunk
• Face (about 10% to 15%): usually the forehead, scalp and around one eye, from the ophthalmic nerve
• Neck, arm, lower back, buttock or leg

Shingles on the face and eye

Shingles affecting the ophthalmic nerve (herpes zoster ophthalmicus) can involve the eye, causing inflammation of the cornea or inside the eye and permanent vision damage. A rash on the tip or side of the nose (Hutchinson sign) suggests the eye is likely to be involved. This needs same-day medical care and an eye exam.

Shingles near the ear

Ramsay Hunt syndrome is shingles of the facial nerve. It causes a painful rash in or around the ear, facial paralysis on that side, and sometimes hearing loss, ringing in the ear and vertigo. Early treatment improves recovery.

Is shingles contagious?

Shingles itself does not spread from person to person. However, fluid from the blisters contains live virus. Someone who has never had chickenpox or the chickenpox vaccine can catch chickenpox (not shingles) by direct contact with the blisters.

You are contagious until all the blisters have crusted over, usually 7 to 10 days. Until then:

• cover the rash with loose clothing or a non-stick dressing
• wash your hands often
• avoid pregnant people who have not had chickenpox, newborn and premature babies, and people with a weak immune system

How shingles is diagnosed

Doctors usually diagnose shingles by its typical one-sided, banded rash and the pain that came before it. If the rash is unusual, widespread or in someone with a weakened immune system, a swab from a blister is tested for virus DNA (PCR). Shingles can be mistaken for herpes simplex, contact dermatitis, insect bites or impetigo.

Treatment

Antiviral medicines

Antiviral tablets (acyclovir, valacyclovir or famciclovir) work best when started within 72 hours of the rash appearing. They shorten the illness, speed healing and reduce pain. They are recommended for:

• people over 50
• anyone with shingles on the face or near the eye
• people with moderate or severe pain or rash
• people with weakened immune systems (who may need IV treatment)
• pregnant people, after specialist advice

They may still be given after 72 hours if new blisters are still forming or the eye is involved.

Pain relief

• Over-the-counter pain relievers: acetaminophen (paracetamol) or ibuprofen at the label dose.
• Prescription options for severe pain: nerve pain medicines such as gabapentin, pregabalin or amitriptyline, and sometimes short courses of stronger painkillers.

Rash care at home

• Keep the rash clean and dry. Wash gently with plain water.
• Cool, damp compresses for 15 to 20 minutes a few times a day can soothe it.
• Calamine lotion can help itching once blisters have dried.
• Wear loose cotton clothing.
• Do not use antibiotic creams or adhesive bandages on the blisters, and avoid scratching.

Complications

• Postherpetic neuralgia (PHN): nerve pain lasting 3 months or more after the rash heals. It affects about 10% to 18% of people with shingles, more in older adults. It can be severe and long-lasting.
• Eye damage: keratitis, uveitis, glaucoma and vision loss from facial shingles.
• Bacterial skin infection of the blisters, sometimes cellulitis.
• Ramsay Hunt syndrome: facial weakness and hearing loss.
• Disseminated zoster: widespread rash and spread to the lungs, liver or brain in people with weak immune systems.
• Neurological complications: encephalitis, meningitis, myelitis and an increased short-term stroke risk.
• Motor weakness in the affected arm, leg or bladder, usually temporary.

Shingles vaccine

The recombinant zoster vaccine (Shingrix) is given as 2 doses, 2 to 6 months apart. It is recommended in the US for:

• all adults aged 50 and over, including those who have had shingles or the older vaccine
• adults 19 and over with a weakened immune system

It prevents more than 90% of shingles in people aged 50 to 69 and remains highly protective for years. It also greatly reduces postherpetic neuralgia. Side effects such as a sore arm, tiredness, muscle aches or fever for 1 to 3 days are common and pass. It contains no live virus, so it is safe for people with weakened immune systems.

Frequently asked questions

What are the first signs of shingles?

Usually burning, tingling, itching or stabbing pain in one area on one side of the body, 1 to 5 days before any rash. Some people also feel tired, have a headache or a mild fever. A rash of red patches and small blisters then appears in the same area.

Is it normal to get soreness down the side of the body where the shingles rash appears?

Yes. Shingles inflames the whole nerve, so pain, aching, burning and tenderness often spread along the band of skin that nerve supplies, beyond the visible rash. This usually fades as the rash heals. Pain lasting more than 3 months after healing is postherpetic neuralgia.

How long does shingles last?

Most cases last 2 to 4 weeks. Pain often starts a few days before the rash, blisters crust over in 7 to 10 days, and the skin heals over the following 1 to 2 weeks. Nerve pain can sometimes persist for months, especially in older adults.

Can you get shingles more than once?

Yes. Most people have shingles only once, but it can recur, especially in people with weakened immune systems. Getting the 2-dose recombinant vaccine after recovering from shingles lowers the chance of another episode.

Is shingles contagious?

You cannot give someone shingles. But fluid from shingles blisters can give chickenpox to someone who has never had chickenpox or the vaccine. Keep the rash covered and avoid pregnant people, newborns and people with weak immune systems until all blisters have crusted.

Can stress cause shingles?

Stress may contribute by weakening immune control of the virus, and many people report a stressful period before an outbreak. However, age and weakened immunity are the main drivers. Shingles is not caused by stress alone; the virus must already be in your body from chickenpox.

Should I get the shingles vaccine if I already had shingles?

Yes. Guidelines recommend the 2-dose recombinant vaccine for adults 50 and over even if they have had shingles, because it can come back. Wait until the rash has fully healed before getting vaccinated.