Pathophysiology of Varicella-Zoster Virus
Varicella-Zoster causes two separate disease 2) initial disease is chickenpox 3) after a latency period (can be decades) patients can develop zoster (shingles)
Signs and Symptoms
Chickenpox – 1) fever 2) malaise 3) painful vesicular rash, starting on head and spreading to limbs, mouth, vagina, and trunk that ulcerates and crusts over in 3-5 days 4) vesicles appear in crops (different areas of body have lesions in different stages) 5) in older children and adults, causes life-threatening interstitial (as opposed to a bacterial intra-alveolar) pneumonia with lung hemorrhage, cough, dyspnea  Zoster – 6) pain preceding eruption of vesicles in dermatomes (most commonly T3-L3) 7) pain sometimes lasts months before resolving (postherpetic syndrome) 8) CNS involvement with fever, headache, vomiting, and photophobia
Characteristic Test Findings
Laboratory – 1) positive Tzanck’s smear 2) increased transaminases 3) CSF shows lymphocytosis and increased protein
Histology/Gross Pathology
1) chickenpox and zoster lesions are identical 2) after chickenpox, the virus becomes latent in dorsal spinal ganglion 3) if it reactivates, it travels along sensory nerves to sensory dermatomes 4) infected cells show characteristic intranuclear inclusions surrounded by a clear zone or halo (Cowdry type A bodies) 5) formation of multinucleated giant cells 6) virus has double-stranded DNA
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