Varicella Pneumonia

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

 

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