Herpes Zoster: Symptoms, Treatment, And Prevention Guide

Author: Reviewed by Dr. Reviewed by Dr. Amanda Oakley, Dermatologist, Hamilton, New Zealand. Synonyms: shingles, zoster, zona

What is herpes zoster?

Herpes zoster, commonly known as

shingles

, is a painful rash caused by the reactivation of the

varicella-zoster virus (VZV)

, the same virus responsible for chickenpox (varicella). After an initial chickenpox infection, typically in childhood, the virus remains dormant in the dorsal root ganglia of spinal and cranial nerves for years or decades. Reactivation occurs when cell-mediated immunity wanes, often due to aging, stress, or immunosuppression, leading to herpes zoster.

The condition manifests as a unilateral, dermatomal vesicular eruption accompanied by significant neuropathic pain. While usually self-limiting, it can lead to serious complications such as

postherpetic neuralgia (PHN)

, particularly in older adults. Shingles affects approximately 1 in 3 people over a lifetime, with incidence increasing sharply after age 50.

Who gets herpes zoster?

Anyone who has had chickenpox is at risk for herpes zoster, as the virus persists lifelong in nerve cells. Risk factors include:

• Age: Incidence rises with age; over 50% of cases occur in those aged 60+ due to declining immunity.
• Immunosuppression: Conditions like HIV, cancer, organ transplants, or medications (e.g., chemotherapy, corticosteroids) increase risk.
• Recent stressors: Physical or emotional stress, trauma, or radiation.
• Female sex and White race show slightly higher incidence in some populations.

People vaccinated against chickenpox or those who received varicella vaccine may still develop milder zoster, though risk is reduced.

What causes herpes zoster?

Herpes zoster results from

reactivation of latent VZV

in sensory ganglia. The virus travels along nerve pathways to the skin, causing inflammation, vesicle formation, and pain in the corresponding dermatome—a skin area supplied by one spinal nerve. Unlike primary varicella, zoster does not spread person-to-person as zoster but can transmit VZV to non-immune contacts, causing chickenpox.

What are the signs and symptoms of herpes zoster?

Shingles evolves in phases:

1. Prodrome (1–5 days): Localized pain, burning, tingling, itching, or hypersensitivity in the affected dermatome; may include fever, malaise, headache.
2. Rash onset: Erythematous macules progress to grouped vesicles on an erythematous base, forming a pseudo-dermatomal pattern. Typically unilateral, does not cross midline.
3. Evolution: Vesicles become pustular (days 3–4), then crust over (7–10 days). Full healing: 2–4 weeks.

Common sites: Thoracic (T5-L1, 50–60%), cranial (ophthalmic: 10–20%), cervical, lumbar, sacral. Pain is neuropathic, described as shooting, burning, or electric.

Variants:

• Zoster sine herpete: Pain without rash.
• Disseminated zoster: >20 lesions outside primary dermatome; seen in immunocompromised.
• Ramsay Hunt syndrome: Cranial nerve VII involvement: ear pain, vesicles in ear canal, facial palsy, hearing loss.
• Hutchinson syndrome: Ophthalmic zoster with eye involvement.

How is herpes zoster diagnosed?

Diagnosis is primarily

clinical

, based on characteristic unilateral dermatomal vesicular rash with pain. Differential includes herpes simplex, contact dermatitis, erysipelas. Confirm with:

• Tzanck smear: Multinucleated giant cells from vesicle base.
• PCR: Gold standard from vesicle fluid.
• Viral culture/DFA: Less sensitive.
• Biopsy rarely needed.

In atypical cases (immunocompromised, disseminated), test to rule out other infections.

What is the treatment for herpes zoster?

Early intervention reduces duration, severity, and PHN risk. Start antivirals within

72 hours of rash onset

:

Drug	Dose (Adults)	Duration
Acyclovir	800 mg PO 5x/day	7 days
Valacyclovir	1 g PO 3x/day	7 days
Famciclovir	500 mg PO 3x/day	7 days

Pain management:

• NSAIDs/acetaminophen initially.
• Gabapentinoids (gabapentin, pregabalin), tricyclics (amitriptyline) for neuropathic pain.
• Opioids for severe pain; corticosteroids adjunct in some cases.

Supportive care: Calamine lotion, oatmeal baths, wet compresses; keep lesions clean/dry to prevent bacterial superinfection. Hospitalize if disseminated, ophthalmic, or immunocompromised.

Herpes zoster complications

Complications occur in 10–18% of cases, more in elderly/immunosuppressed:

• Postherpetic neuralgia (PHN): Pain persisting >90 days post-rash; affects 10–20% over 60.
• Ocular: Keratitis, uveitis, retinal necrosis (vision loss).
• Neurologic: Motor weakness (5–10%), meningitis, encephalitis.
• Visceral: Pneumonia, hepatitis (immunocompromised).
• Secondary bacterial infection.

How can herpes zoster be prevented?

Vaccination: Two recombinant vaccines: Shingrix (preferred, 90–97% efficacy, 2 doses IM 2–6 months apart, age ≥50 or immunocompromised ≥19); Zostavax (live, less effective). Reduces zoster and PHN risk dramatically.

Contact precautions: Cover lesions until crusted; avoid high-risk contacts (non-immune infants, pregnant, immunocompromised).

What is the outcome for herpes zoster?

In uncomplicated cases, rash heals in 3–5 weeks; pain resolves similarly in young/healthy. Elderly: prolonged healing, higher PHN risk (up to 50% if >80 untreated). Disseminated: higher morbidity/mortality. Early antivirals improve outcomes.

Herpes zoster in specific populations

Immunocompromised patients

Higher risk of dissemination, visceral involvement; use IV acyclovir if severe. Airborne/contact precautions.

Pregnancy

Rare; treat aggressively to prevent fetal varicella syndrome.

Frequently Asked Questions

Is shingles contagious?

No, you can’t catch shingles, but uncovered rash can transmit chickenpox to susceptible people until crusted.

Can I get shingles more than once?

Yes, ~4–6% recurrence; vaccination reduces risk.

How long is shingles contagious?

From vesicle appearance until all crusted (7–10 days).

Does shingles vaccine guarantee prevention?

No, but Shingrix is >90% effective.

What if shingles affects the eye?

Ophthalmic zoster requires urgent antiviral + ophthalmology consult.