Shingles and Complications 3/11/2019

Thanks Elan for presenting a case of a 91 year old F presenting with a progressively painful and erythematous rash, 2 weeks after she was treated with presumed Shingles by her PCP. It turned out that she had superimposed cellulitis over her healing Shingles lesions and possibly elements of post-herpetic neuralgia, requiring a Dilaudid PCA for pain control.

Lame joke of the day: Shingles + Cellulitis = Shinglelitis, get it?


Shingles

Epidemiology

  • Risk inc with age, esp for pts > 50, but it can develop at any age
  • Fortunately, most people will only have one outbreak in their life time, < 4% recurrence

Pathophysiology

  • Reactivation of the varicella zoster virus in sensory ganglia after a long latency period following primary infection from varicella (chicken pox). When the virus activates, the virus travels down the nerve fibers to the skin, hence a dermatomal distribution.
  • Weakening of the immune system is associated with outbreaks, i.e. AIDS, lymphoma, immune-suppressives.

Presentation

  • 2-3 days prior to rash: pt might develop a tingling sensation, hypersensitivity, or itching over a particular dermatome. Later on vesicles on an erythematous base develop. Painful and very sensitive.
  • Blisters form over 3-5 days, then dry and crust over the next 5 days
  • Blisters are CONTAGIOUS until the vesicles scab over.
    • Keep affected area dry and clean!
  • Expanding rash or blisters that persist for > 2 weeks indicate immune-compromised status

Complications

  • Most common is post-herpetic neuralgia
    • 10% of patients, inc with age
    • Pain can be very debilitating, some patients need to be admitted for pain control.
  • Zoster ophthalmicus
    • Involves the eye, seen in 10-25% of cases when shingles hit V1
    • Antiviral should be administered ASAP, preferably within 72 hours of onset of sx.
    • Valacyclovir is recommended, 7-day course, 1000mg PO TID
    • Alternative: Acyclovir 800mg PO 5 times daily x 7-10 days, Famciclovir 500mg PO TID.
    • If e/o keratitis or uveitis, topical steroids can be used.
    • Can lead to vision loss, especially with corneal scarring. Some patients would require corneal transplant.
    • Post-herpetic neuralgia occurs in 36.6% of pts over 60, and 47.5% over age 70.
  • Disseminated zoster
    • If > 3 contiguous dermatomes or 2 separated dermatomes are affected.
  • Bacterial infection of the skin:
    • Risks inc with scratching
    • Inc risk of scarring
  • Ramsey Hunt Syndrome:
    • Reactivation of VZV at the geniculate ganglion.
    • Triad of Ipsilateral facial paralysis, ear pain, vesicles on face/ear or IN THE EAR. Can lead to deafness, tinnitis or vertigo due to vestibulocochlear nerve involvement.
    • Mgx: Anti-viral within 72 hours, steroids. Hearing loss is likely permanent so treat ASAP.

Diagnosis

  • Primarily clinical
  • Swabbing ulcer/vesicular fluid for HSV PCR has high sensitivity, quick turn around time.

Management

  • Acute management
    • Anti-viral: Valacyclovir, famiciclovir, acyclovir. Start ASAP and preferably even before blisters occur. Effectiveness is greatest if antiviral is started within 72 hours of onset of symptoms (even before vesicles appear if clinical suspicion is high enough!)
    • IV antiviral recommended for disseminated disease
    • Options: Acyclovir (5 times a day dosing), Valacyclovir (TID dosing), famiciclovir (TID as well).
    • Help shorten duration and complications
    • Pain control:
      • Lidocaine, capsaicin, gabapentin, Lyrica.
      • Use opioids if and only if necessary.
      • Antidepressants i.e. Cymbalta and Effexor have variable benefits for post-herpetic neuralgia.
    • Keep area dry and clean, DO NOT SCRATCH.
  • Infection Control:
    • Localized herpes zoster: Standard precautions, contact
    • Disseminated: airborne + contact
    • Immunocompromised patient: airborne + contact regardless
  • Post-exposure:
    • Previously received 2 doses of varicella vaccine: Monitor for 8-21 days for sx
    • Previously only received 1 dose of varicella vaccine: Should get the 2nd dose ASAP (minimum of 4 weeks apart from 1st dose). Monitor for sx.
    • No prior vaccination: Potentially contagious from days 8-21 post exposure, should be removed from patient care duties. Post-exposure vaccination should be provided ASAP. If varicella vaccination is contraindicated (i.e. pregnant), varicella-zoster immune globulin is recommended.
  • Vaccination/Prevention
    • Vaccinate children
    • Vaccinate adults > 50 regardless of whether they have had chicken pox or shingles and regardless of whether they had the older vaccine
      • Older: Weakened live virus, Zostavax
      • Newer: Recombinant Herpes Zoster vaccine, Shingrix, 2 doses IM, 2-6 months apart, at least 2 months after the older vaccine. Contains inactivated parts of the virus, not a live vaccine.
        • Effectiveness: 97% effective in preventing shingles for pts > 50, vs Zostavax which is 50-64% effective.
        • Reduces post-herpetic neuralgia if you get it shingles

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