Herpes Zoster (Shingles)

• Latent varicella-zoster virus (VZV) lies dormant in nerve root ganglion. Typically, there is very little, smoldering activity.
• During VZV "reactivation", VZV replicates to a critical threshold and spreads within the dorsal root ganglion and tracks down the sensory nerves to spread into the skin in a dermatomal distribution.

• Pain precedes rash by ~ 3 to 7 days.
• Vesicles develop over several days in a dermatomal distribution (most commonly along a thoracic level) or in a cranial nerve distribution.
• The most commonly affected cranial nerves are CN 5, the trigeminal nerve and CN 7, the facial nerve. CN 8, the vestibulocochlear nerve, runs in close proximity to CN 7 and so CN 8 is also often affected.
• Ramsay Hunt Syndrome is the eponym used to described a syndrome that involves both CNs 7 and 8, with symptoms/signs of ipsilateral facial paralysis, otalgia (inner ear pain), vesicles in the auditory canal or auricle, and potentially vestibular symptoms (eg, nystagmus) or auditory symptoms (eg, tinnitus).
• Patients are no longer contagious after 10 days of rash.
• Postherpetic neuralgia is persistent neuralgia 90 days post rash.

• Recombinant zoster vaccine (RZV) has been shown to be more effective than Zoster live vaccine (ZVL) but has more side effects. However, the side effects are typically transient (1 - 3 days), so it is generally recommended that when possible the recombinant zoster vaccine should be given.
• VZV vaccination is loosely recommended in those 50+ years-old and strongly recommended in those 60+ years-old.

7 days of treatment of any of the following are typically recommended:

• Valacyclovir 1000 mg PO three times daily
• Famciclovir: 500 mg PO three times daily
• Acyclovir: 800 mg PO five times daily

Numerous complications can occur from shingles including but not limited to:

• Postherpetic neuralgia
• Disseminated zoster
• 3 or more contiguous dermatomes or any non-contiguous dermatomes.
• Bilateral dermatomal distribution.
• Visceral involvement
• Herpes zoster ophthalmicus or Acute retinal necrosis
• Ramsay Hunt syndrome
• Meningoencephalitis, Myelitis, or Radiculitis (Guillain-Barre Syndrome)

Clinical Presentations and Outcome Studies of Cranial Nerve Involvement in Herpes Zoster Infection: A Retrospective Single-Center Analysis Herpes Zoster Rash