Herpes Zoster Flashcards
What is herpes zoster?
Acute dermatological infection associated with reactivation of VZV (VARICELLA ZOSTER VIRUS)
What are the clinical findings of herpes zoster?
Unilateral dysesthesia (generic term for cutaneous symptoms eg pruritis or burning) every 3-5 days after pain and parasthesia (burning or prickling sensation) of the dermatome - a vesicular or bullous eruption to a dermatome (area of skin that sends info to the brain via a single spinal nerve) innervated by a corresponding sensory ganglion
Pain may be pre herpetic, synchronous with rash or post herpetic
What is dysesthasia?
Generic word for a cutaneous symptom eg pruritis, burning tingling etc
What is a major morbidity for herpes zoster?
Post herpetic neuralgia (pain in the nerves)_
What is a clinical sign of eye involvement with herpes zoster?
Hutchinson’s sign - shingles on top of nodes signifies eye involvement due to involving the nasociliary branch of ophthalmic nerve indicates eye involvement
What is the distribution of herpes zoster on the body?
Thoracic (50%)
Trigeminal (10-20%)
Cervical (10-20%)
What are risk factors for herpes zoster?
Immunosuppression
Old age
Associated with haematological malignancy sometimes
What is the d/d for herpes zoster? q
Before thoracic pain occurs, must consider other causes of chest pain
Contact dermatitis
Localised bacterial infection
Zosteriform HSV
What is the management for herpes zoster?
Compress with normal saline, Burow’s, or Betadine solution
Analgesics eg NSAID
Acyclovir, famcyclovir or valacyclovir for 7 days, must initiate within 72 hours for benefit
Gabapentin 300-600mg PO tie for post herpetic neuralgia
Supportive therapy - bed rest, sedation, pain management with analgesics, moist dressing
Post herpetic neuralgia - gabapentin, pregabalin, tricyclic antidepressants
What is the diagnosis for herpes zoster in each stage?
Prodromal stage - suspect zoster in older or immunocompromised with unilateral pain
Active vesiculation - clinical findings usually adequate, many be confirmed by Tzanck test, DFA or viral culture to rule out HSV infection
Post herpetic pain syndrome - by history and clinical findings
