Herpes Zoster (Shingles) ICD-10: B02.9

Viral skin infection / Neurological condition

Often searched as: shingles rash, painful rash one side of body, blisters following a nerve line, burning pain then rash, rash on ribs one side, chickenpox virus reactivation, shingles symptoms, shingles near eye…

Clinical urgency level

lowmediumhigh

Systems Affected

skinperipheral nervous systemeyes (when ophthalmic branch is involved)ears (Ramsay Hunt syndrome)

Severity Levels

mild

Localized unilateral rash on the trunk with moderate pain, no complications — manageable with antiviral treatment started within 72 hours of rash onset.

moderate

More painful episode with significant nerve pain, rash on the face or near the eye, or involving elderly patients with higher complication risk.

severe

Ophthalmic zoster (threatens vision), Ramsay Hunt syndrome (facial paralysis, hearing loss), disseminated zoster (in immunocompromised), or severe postherpetic neuralgia lasting months to years.

Red Flags

Rash or blisters appearing on or near the eye, nose tip, or forehead (ophthalmic zoster — risk of blindness)
Facial drooping, hearing loss, or ear pain with blisters in or around the ear (Ramsay Hunt syndrome)
Widespread blistering not confined to one side of the body (disseminated zoster — immune emergency)
Rash in an immunocompromised person (HIV, cancer, transplant)
Severe burning or stabbing pain starting before rash appears — start antivirals early
Shingles in a person under 50 with no known risk factor — consider HIV testing

Clinical Presentation

Herpes zoster (shingles) — grouped vesicles on erythematous base along a thoracic dermatome

Source: Wikimedia Commons (CC BY-SA 3.0 )

Herpes zoster image gallery — DermNet NZ

View gallery on DermNet NZ (image gallery reference)

When to See a Doctor

See a doctor as soon as possible — ideally within 72 hours of rash onset — for antiviral treatment (acyclovir, valacyclovir) which significantly reduces pain duration and complication risk. Seek emergency care immediately if the rash involves the eye area or if you have facial weakness or hearing changes alongside the rash.

Differential Diagnosis

Herpes simplex (HSV) — similar blisters but not dermatomal
Contact dermatitis (linear if from plant — no pain prodrome)
Impetigo (bacterial — crusted, no nerve pain)
Cellulitis (spreading redness — no vesicles)
Zosteriform metastases (rare — cancer mimicking shingles distribution)
Pre-eruptive zoster (pain only, before rash — can mimic cardiac, renal, or musculoskeletal pain)

Comorbidities

Postherpetic neuralgia (PHN) — chronic nerve pain after rash resolves, especially in elderly
Zoster ophthalmicus — corneal damage, glaucoma, vision loss
Ramsay Hunt syndrome — facial nerve palsy, hearing loss
Immunosuppression (HIV, malignancy, corticosteroid use)
Increased risk of stroke in weeks following shingles episode
Depression from chronic pain

Prognosis

The acute rash typically heals within 2–4 weeks. The most feared complication is postherpetic neuralgia (PHN) — persistent pain lasting months or years after rash resolution — affecting up to 30% of untreated patients over 60. Early antiviral treatment significantly reduces PHN risk. The shingles vaccine (Shingrix) is ~90% effective at preventing herpes zoster and is recommended for adults over 50. Once you've had shingles, recurrence is uncommon but possible.

Detailed Overview

Causes, Symptoms, and When to Take Action Herpes zoster, also known as shingles, is a reactivation of the varicella-zoster virus, which lies dormant in nerve ganglia after an initial chickenpox infection. It causes a painful, unilateral rash along a dermatome and may have systemic symptoms. How It Looks Texture: Painful grouped vesicles on an erythematous base, which may become crusted over time. Color: Red or inflamed skin underlying fluid-filled blisters. Shape: Vesicles appear in clusters along the distribution of specific sensory nerves (dermatomes), usually on one side of the body. Location: Commonly on the trunk or face; nerve distribution determines the area. Why Does It Appear? The virus reactivates from latency in sensory nerve ganglia. Reactivation may be preceded by prodromal symptoms like pain, tingling, or sensitivity in the corresponding dermatome. Risk increases with aging, weakened immune function, and prior skin/nervous system injury. Should You Be Concerned? Though often self-limited, Herpes zoster can lead to complications: Severe pain and discomfort during the acute phase. Risk of postherpetic neuralgia (persistent pain lasting after the rash resolves), which can reduce quality of life. Involvement of certain areas (e.g. ophthalmic branch of trigeminal nerve) needs prompt attention. Can You Prevent It? While reactivation cannot always be prevented, certain measures may reduce risk or severity: Early recognition of symptoms, especially prodromal pain in a dermatome. Protecting your overall immune health. Avoiding trauma or irritation in affected skin areas. 👉 How Piel AI Can Help Piel AI assists in tracking rash appearance and progression over time through regular imaging. Though not diagnostic, it supports identifying changes in rash spread, severity, or persistence to discuss with a healthcare provider. Summary Herpes zoster is caused by reactivation of varicella-zoster virus, with painful, vesicular rash along a dermatome. Prodromal symptoms often precede visible rash. Potential complications include long-lasting pain after rash resolves and involvement of critical areas. Monitoring, early detection, and awareness are essential.

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