Chickenpox and Shingles: VZV Infection, Reactivation, and Management

Varicella-zoster virus (VZV / HHV-3) causes two distinct syndromes:

Chickenpox (Primary Varicella)

• Childhood illness; highly contagious (respiratory, vesicle fluid).
• Incubation 10–21 days. Prodrome: fever, malaise.
• Rash: centripetal, crops of vesicles on erythematous base → crust. All stages simultaneously.
• Self-limited (5–7 days). Complications: bacterial superinfection, pneumonia, encephalitis, Reye syndrome (aspirin).

Shingles (Herpes Zoster)

• Reactivation from dorsal root/ganglion latency (waning cell-mediated immunity).
• Age >50 or immunocompromised.
• Dermatomal distribution (unilateral, midline stop). Pain → vesicles → crust (2–4 wks).
• Complications: PHN (pain >90 days), ophthalmicus (vision loss), Ramsay Hunt (facial nerve), myelitis.

Prevention & Treatment

• Varicella vaccine (live attenuated) 2-dose: 90% effective.
• Shingrix (recombinant subunit) 2-dose >90% efficacy >50 yrs; preferred over Zostavax.
• Antivirals (acyclovir, valacyclovir, famciclovir): within 72 hrs rash onset reduces severity/duration; essential for shingles, high-risk varicella.
• Pain management: gabapentinoids, TCAs, opioids for PHN.