Shingles (herpes zoster)
Painful blisters in one band on one side. Start an antiviral within 72 hours if eligible, and check the nose tip for eye involvement.
A 68-year-old man with diabetes has had burning pain on the left side of his chest for 4 days, and for 2 days a band of red patches with clusters of blisters following the same area, not crossing the midline.
Another patient, 72, has blisters on the right forehead and the tip of the nose, with a red, painful right eye.
Who needs antivirals, and who needs the eye team today?
- Eye involvementRash on the forehead or nose tip (Hutchinson's sign), red or painful eye: same-day eye review.
- Immunosuppressed, widespread or unwellAntivirals (often IV), senior.
- Antivirals within 72 hoursOver 50, severe pain or rash, non-truncal, immunosuppressed, eye or ear involvement.
- Pain reliefParacetamol, NSAID, then neuropathic agents if severe.
- Ear pain with facial weaknessRamsay Hunt syndrome: antivirals and ENT.
- Infection controlCover the rash, keep away from pregnant women, newborns and the immunosuppressed who aren't immune.
- Post-herpetic neuralgiaAmitriptyline, pregabalin or gabapentin, capsaicin later.
- Eye involvement or visual symptoms
- Facial weakness or ear vesicles
- Immunosuppressed
- Widespread or disseminated rash
- Confusion, headache or neck stiffness
- Weakness in the affected limb
- Herpes zoster ophthalmicus
- Ramsay Hunt syndrome
- Disseminated zoster
- Zoster encephalitis or meningitis
- HIV or immunosuppression (shingles in a young adult)
- Pain before the rash mistaken for MI, gallbladder or renal colic
| Aciclovir | 800 mg orally 5 times daily for 7 days |
| Valaciclovir | 1 g orally 3 times daily for 7 days |
| Start | Within 72 hours of rash onset (later if new lesions, eye or ear involvement, or immunosuppressed) |
| Hutchinson's sign | Rash on the tip or side of the nose: eye involvement likely |
| Contagious | Until lesions crust (spreads chickenpox to non-immune people) |
| Post-herpetic neuralgia | Pain lasting over 3 months after the rash |
Check every dose against a current drug reference and your hospital protocol.
On this page
What is shingles?
Reactivation of varicella-zoster virus that has lain dormant in a sensory nerve ganglion since chickenpox. It causes pain and a blistering rash in one dermatome, usually on one side of the body, not crossing the midline. It is more common and more severe in older people and the immunosuppressed.
Presentation
- Prodrome: burning, tingling or stabbing pain in a band for 1–5 days before the rash. Can mimic MI, gallbladder pain or renal colic.
- Rash: red patches, then clusters of blisters that crust over 7–10 days, in one dermatome.
- Common sites: thoracic (chest and back), then the ophthalmic division of the trigeminal nerve (forehead, eye).
Who needs antivirals?
- Antiviral now (IV if severe or immunosuppressed)
- eye team or senior
Oral antiviral for 7 days
- Antiviral optional
- pain relief and advice
Special sites
| Site | Clues | Action |
|---|---|---|
| Ophthalmic (forehead, eye) | Hutchinson's sign (nose tip), red painful eye, blurred vision | Same-day eye review, antivirals |
| Ramsay Hunt (geniculate ganglion) | Ear pain, vesicles in the ear canal or palate, facial weakness, hearing loss, vertigo | Antivirals, ENT; steroids per specialist |
| Sacral | Urinary retention, constipation | Check bladder |
| Motor (limb) | Weakness in the affected limb | Usually recovers |
Differential diagnosis
| Condition | Clues |
|---|---|
| Herpes simplex | Recurrent at the same spot, smaller area |
| Contact dermatitis | Itch more than pain, matches contact |
| Impetigo | Honey-coloured crusts, children |
| Cellulitis | Spreading redness, no vesicles |
| Pre-rash pain | Chest pain (MI), right upper quadrant (gallbladder), loin (renal colic): examine and test as needed |
Treatment
Infection control
- Shingles can give chickenpox to people who aren't immune, by contact with fluid from the blisters.
- Keep the rash covered. Avoid contact with pregnant women, newborns and immunosuppressed people who haven't had chickenpox until the lesions crust.
- Healthcare workers with shingles should follow local occupational health advice.
Common mistakes
- Missing ophthalmic shingles (look at the nose tip).
- Starting antivirals too late, or not at all in older patients.
- Calling pre-rash chest pain "musculoskeletal" without an ECG.
- Missing Ramsay Hunt syndrome in someone with facial weakness.
- Forgetting to adjust aciclovir for kidney function.
- Not offering pain relief that works.
Frequently asked questions
Who needs antiviral treatment for shingles?
People over 50, those with severe pain or rash, rash on the face or eye, ear involvement, and immunosuppressed patients, ideally within 72 hours of the rash.
What is Hutchinson's sign?
Shingles on the tip or side of the nose, which suggests the eye is involved. Same-day eye review is needed.
Is shingles contagious?
Not as shingles, but the blister fluid can give chickenpox to people who aren't immune until the lesions crust.
What is post-herpetic neuralgia?
Nerve pain lasting more than 3 months after the rash. It is more common in older people and is treated with amitriptyline, pregabalin or gabapentin.
Test yourself
Exam-style questions on this guide, from our two question banks. Choose an answer to see why each option is right or wrong.
1. A patient with shingles has vesicles on the tip of the nose. What does this suggest?
Answer: Eye involvement. Hutchinson's sign: nasociliary nerve involvement; same-day eye review.
- Dissemination: Not necessarily.
- Mild disease: No.
- Ramsay Hunt syndrome: Ear and facial nerve.
- Impetigo: No.
2. A 68-year-old has a 2-day painful truncal shingles rash. What is the best treatment?
Answer: Oral aciclovir. Aciclovir 800 mg 5 times daily (or valaciclovir) for 7 days within 72 hours.
- IV aciclovir: Not needed if immunocompetent and truncal.
- No treatment: Over 50 benefits from antivirals.
- Antibiotics: Viral.
- Steroid cream: No.
3. A man has ear pain, vesicles in the ear canal and facial weakness. What is the diagnosis?
Answer: Ramsay Hunt. Zoster of the geniculate ganglion: antivirals and ENT review.
- Otitis externa: No facial weakness.
- Stroke: Vesicles point to zoster.
- Mastoiditis: No.
- Bell's palsy: No vesicles.
4. A 70-year-old has a painful vesicular rash over the left forehead and upper lid, with vesicles on the tip of the nose. What does the nose involvement signify and what should be done?
Answer: Hutchinson sign — antivirals. Herpes zoster ophthalmicus: reactivation of VZV in the ophthalmic division (V1) of the trigeminal nerve; more common in elderly and immunocompromised (consider HIV in young). Hutchinson sign — lesions on the side/tip of the nose (external nasal branch of the nasociliary nerve, which also supplies the globe) → strong predictor of ocular involvement: conjunctivitis, keratitis (pseudodendrites), anterior uveitis (with raised IOP, sectoral iris atrophy), scleritis, retinitis, optic neuritis, cranial nerve palsies. Treat: oral aciclovir 800 mg five times daily (or valaciclovir/famciclovir) for 7–10 days, ideally within 72 hours; analgesia; ophthalmology review; topical steroids for uveitis under specialist care. Complications: post-herpetic neuralgia. Shingles vaccine prevents it.
- Bacterial rash — antibiotics: Dermatomal vesicles are viral zoster, not bacterial.
- Contact dermatitis — reassure: Dermatomal vesicles are herpes zoster, not contact dermatitis.
- Shingles — topical steroids: Topical steroids are not the treatment; oral antivirals and eye review are needed.
5. A 70-year-old has a painful vesicular rash in a band on the left side of the chest that started 2 days ago. What is the treatment?
Answer: Oral valaciclovir. Herpes zoster (VZV reactivation): dermatomal pain then vesicular rash not crossing midline; older and immunocompromised more often. Oral antivirals (aciclovir, valaciclovir, famciclovir) within 72 hours of rash reduce acute pain and complications; analgesia. Complications: postherpetic neuralgia (amitriptyline, gabapentin, pregabalin), ophthalmic zoster (Hutchinson sign — urgent eye review), Ramsay Hunt, disseminated disease. Recombinant zoster vaccine for older adults.
- Potent topical steroid: Topical steroids do not treat shingles.
- Oral flucloxacillin: Shingles is not bacterial.
- No treatment needed: Antivirals within 72 hours reduce pain and complications.
6. A man with facial palsy also finds normal sounds painfully loud and has lost taste on the front of his tongue. Where is the facial nerve lesion?
Answer: Above the nerve to stapedius. Inside the temporal bone, the facial nerve gives off the greater petrosal nerve (at the geniculate ganglion), the nerve to stapedius, then the chorda tympani. A lesion above the nerve to stapedius causes hyperacusis (stapedius cannot damp loud sounds) plus loss of taste. A lesion at the stylomastoid foramen affects only facial muscles.
- At the stylomastoid foramen: Causes facial weakness only.
- Within the parotid gland: Affects only some facial branches.
- In the cerebral cortex: Upper motor neuron lesion spares the forehead and does not cause hyperacusis.
- In the buccal branch alone: Affects only part of the face.
7. Why is aciclovir selectively toxic to herpes-infected cells?
Answer: Activated by viral thymidine kinase. Aciclovir is phosphorylated mainly by viral thymidine kinase, so it becomes active only in infected cells, then terminates viral DNA chains. Resistance comes from thymidine kinase mutations. High IV doses can cause crystal nephropathy, so patients must be well hydrated.
- Blocks viral entry into cells: Not its mechanism.
- Inhibits viral neuraminidase: Oseltamivir.
- Blocks viral reverse transcriptase: HIV drugs.
- Induces interferon production: Not its mechanism.
References and dose sources
- NICE CKS — Shingles
- Aciclovir dosing: Drugs.com: Acyclovir (aciclovir) dosage (see also our aciclovir dose page)
- Valaciclovir dosing: Drugs.com: Valacyclovir dosage (see also our valaciclovir dose page)
- Paracetamol dosing: Drugs.com: Acetaminophen (paracetamol) dosage (see also our paracetamol dose page)
- Amitriptyline dosing: Drugs.com: Amitriptyline dosage (see also our amitriptyline dose page)
- Pregabalin dosing: Drugs.com: Pregabalin dosage (see also our pregabalin dose page)
International guidance is linked where it reflects good practice. Where your hospital’s protocol differs, follow your hospital.