Joe presented the case of a young man from Mexico with unknown immunization history who presented with acute onset of AMS, fevers, and a progressive vesicular rash, diagnosed with primary varicella infection (chickenpox!), now in the ICU with varicella pneumonia and likely varicella vasculitis induced stroke.

Clinical Pearls

• Vaccinate your kids!
• Two main VZV presentations are primary infection (chickenpox) and reactivation (shingles, disseminated zoster in immunocompromised individuals)
• Varicella rash presents as vesicular lesions at varying stages.  Vesicular lesions at the same stage of development are concerning for smallpox.
• The most common complication of primary VZV in adults is pneumonia.  Treatment is with IV acyclovir.
• The most common neurologic complication of primary VZV is encephalitis.  No approved therapy exists.
•  Isolation precautions for shingles is contact.  For disseminated zoster or chickenpox, make sure you patient is on contact and airborne precautions.

Differential for fever, rash, and pharyngitis:

• Measles
• Mono (due to EBV, CMV, toxo, HHV6)
• Acute HIV
• Parvovirus
• Zoster
• HSV
• Mycoplasma

Fever and rash emergencies:

• Meningococcemia
• Subacute bacterial endocarditis
• Rocky Mountain Spotted Fever
• Necrotizing fasciitis
• Toxic epidermal necrolysis
• Toxic shock syndrome (staph aureus or GAS)

Varicella zoster (VZV)

• Primary infection – chickenpox
  • Clinical manifestations:
    • Prodrome of fever, malaise, pharyngitis, loss of appetite
    • Rash is often pruritic and occurs in successive crops over days (new vesicle formation stops after 4 days). Vesicular lesions at varying stages on an erythematous base on the trunk, face, and extremities.
  • Diagnosis:
    • send swab (from ulcer base) for HSV PCR and DFA.  These have quick turn around time and high sensitivity.  Viral culture takes weeks and is less sensitive.
  • Most common complications
    • Children: skin infection
    • Adults:
      • Pneumonia (1/400 cases) with a mortality of 10-30%. In people requiring mechanical ventilation, mortality reaches 50%.
        • Risk factors for pneumonia development are cigarette smoking, pregnancy, immunosuppression, and male sex.
        • Develops 1-6 days after the appearance of rash
        • CXR usually with diffuse bilateral infiltrates with possible nodular component in early stages
        • Prompt administration of acyclovir has been associated with clinical improvement
      • Neurologic:
        • Encephalitis: acute cerebellar ataxia (more common in children), diffuse encephalitis (more common in adults)
          • No proven therapy once encephalitis occurs. Acyclovir has been used with anecdotal success
        • Transient focal deficits
        • Aseptic meningitis
        • Transverse myelitis
        • Vasculitis (medium to large vessel vasculopathy)
        • Hemiplegia
      • Hepatitis
        • More common in immunocompromised hosts and frequently fatal
      • Other
        • Diarrhea, pharyngitis, otitis media
  • Treatment
    • For healthy children <12 ⇒ nothing
    • For adults
      • if no complications, then oral valacyclovir (1g TID) or acyclovir (800 mg 5 times/day)
        • if immunocompromised ⇒ treat with IV acyclovir if active lesions present (10mg/kg q8h)
      • if complications
        • acyclovir IV 10mg/kg q8h for 7-10days
      • contact and airborne precautions!
• Reactivation – shingles
  • Clinical manifestations –
    • Rash – most common location is thoracic and lumbar dermatomes
      • Localized, painful and restricted to a dermatome
      • Disseminated if > 3 contiguous dermatomes or 2 dermatomes on separate parts of the body, painful
    • Acute neuritis – 75% of patients have pain/burning/throbbing prior to onset of rash
  • Complications in immunocompetent hosts –
    • post-herpetic neuralgia (most common), superficial skin infections, ocular complications (acute retinal necrosis and zoster ophthalmicus), motor neuropathy, meningitis, Ramsay hunt syndrome (zoster oticus)
  • Treatment
    • For patient with localized disease presenting <72 hours after clinical symptom onset, treat with oral acyclovir, valacyclovir, or famciclovir
    • For patient with localized disease presenting >72 hours after disease onset, then monitor
    • Pregnant women, treat with acyclovir
    • Disseminated disease, treat with IV acyclovir