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Postherpetic neuralgia
Other Resources UpToDate PubMed

Postherpetic neuralgia

Contributors: Andrea Wasilewski MD, Richard L. Barbano MD, PhD
Other Resources UpToDate PubMed


Herpes zoster infection can occur from reactivation of the herpes varicella-zoster virus or from primary infection. In two-thirds of adults, reactivation is characterized by severe pain and paresthesias in a dermatomal distribution, followed 1-2 weeks later by the appearance of a vesicular rash. The thoracic, cervical, and trigeminal dermatomes are most commonly involved. Approximately 25% of patients have residual neuropathic pain lasting greater than 4 months following resolution of the rash, a condition known as postherpetic neuralgia (PHN).

The risk of developing PHN increases with age. In patients with persistent pain following rash resolution, pain and temperature sensation are hyper-acute, leading to severe pain even with light touch (allodynia) or episodes of unpredictable shooting or stabbing pain. PHN is a clinical diagnosis. Neuralgiform symptoms can persist from weeks to a lifetime.

Related topics: varicella, disseminated herpes zoster


B02.29 – Other postherpetic nervous system involvement

2177002 – Postherpetic neuralgia

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Diagnostic Pearls

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Differential Diagnosis & Pitfalls

  • Trigeminal neuralgia
  • Migraine headache
  • Cluster headache
  • SUNCT (short-lasting unilateral neuralgiform headache with conjunctival injection and tearing)
  • Paroxysmal hemicranias
  • Peripheral neuropathy (eg, Diabetic neuropathy, drug-induced neuropathy, Meralgia paresthetica)
  • Mononeuritis multiplex
  • Nerve tumor (eg, Neurilemmoma)
  • Traumatic nerve injury
  • Contact dermatitis (Allergic contact dermatitis, Irritant contact dermatitis), Atopic dermatitis, or skin irritation
  • Radiculitis (see Radiculomyelitis)

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Last Reviewed:07/30/2018
Last Updated:04/11/2021
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Postherpetic neuralgia
Copyright © 2024 VisualDx®. All rights reserved.