Acute Rash-Associated Pain in Herpes Zoster
Placeholder: acute dermatomal pain accompanies the shingles rash.
- Days 1–5: Pain onset (Placeholder timing note)
- 5–8/10: Typical VAS score (Placeholder severity note)
- 1–3: Dermatomes affected (Placeholder distribution note)
- 2–4 wks: Rash duration (Placeholder duration note)
Rash and acute neuritis
Placeholder: reactivated virus inflames the nerve and skin together.
Sensory Nerve Fiber Injury Along the Dermatome
Placeholder: viral replication damages sensory axons and ganglia.
- Dorsal root: Ganglion involved (Placeholder location note)
- A-delta, C: Fiber types hit (Placeholder fiber note)
- Age-linked: Damage severity (Placeholder risk note)
- Weeks–months: Recovery window (Placeholder recovery note)
Axonal injury and demyelination
Placeholder: older patients show greater nerve fiber loss.
Aberrant Pain Signal Generation and Central Sensitization
Placeholder: injured fibers generate spontaneous ectopic firing.
- Elevated: Ectopic firing (Placeholder mechanism note)
- Common: Central sensitization (Placeholder spinal note)
- ~30%: Allodynia rate (Placeholder symptom note)
- Irregular: Signal pattern (Placeholder pattern note)
Ectopic firing and spinal amplification
Placeholder: damaged fibers misfire and amplify pain centrally.
Effect of Antiviral Treatment Timing on Pain Outcomes
Placeholder: earlier antiviral therapy reduces nerve damage extent.
- <72 hrs: Ideal start window (Placeholder timing note)
- Worse pain: Delayed start effect (Placeholder outcome note)
- Acyclovir class: Common antivirals (Placeholder drug note)
- Moderate: Benefit magnitude (Placeholder effect note)
Treatment window and nerve protection
Placeholder: fast antiviral start limits viral nerve injury.
Chronic Pain Trajectory Over Months — Resolution or Persistence
Placeholder: pain either fades over months or persists as PHN.
- ~10–20%: PHN at 3 months (Placeholder prevalence note)
- ~5–10%: PHN at 1 year (Placeholder prevalence note)
- Much higher: Older age risk (Placeholder risk note)
- 1–12 months: Typical resolution (Placeholder timeline note)
Long-term pain resolution patterns
Placeholder: trajectory depends on age, severity, and treatment timing.
Placeholder: older patients with delayed treatment face longer chronic pain.