Chickenpox
Chickenpox is the primary infection with varicella-zoster virus, a pruritic centripetal eruption in which macules, papules, vesicles, pustules, and crusts coexist because new crops appear while earlier lesions mature. Most otherwise healthy children need only supportive care, while adults, adolescents over 12 years, and other higher-risk patients are treated with oral acyclovir 800 mg by mouth four times daily for 5 days, started as early as possible after rash onset.
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What this article covers
- Overview
Chickenpox is the primary infection with varicella-zoster virus (VZV), distinct from herpes zoster, the later dermatomal or disseminated reactivation of the same virus after it becomes latent.
- Epidemiology
Chickenpox can affect patients of any age, most often presenting in childhood, and is typically self-limited when it occurs in an otherwise healthy child.
- Risk factors
No evidence of varicella immunity: no laboratory-confirmed disease or immunity, no provider diagnosis or verification of prior varicella or zoster, and no documented age-appropriate vaccination.
- Pathophysiology
VZV spreads by airborne virus, respiratory secretions, and direct contact with vesicular fluid, establishing primary infection after an incubation period of 10 to 21 days.
- Clinical features
This is usually a clinical diagnosis established by the combination of fever and a pruritic centripetal eruption in which lesions at every stage (macules, papules, clear vesicles, pustules, crusts)…
- Differential diagnosis
Herpes zoster: grouped vesicles or pustules on an erythematous base extending along a single dermatome, often preceded by acute neuralgia; unlike chickenpox, the eruption is confined to one dermatome…
- Diagnosis
Typical disease is often recognized clinically from the pruritic centripetal eruption with simultaneous multi-stage lesions plus fever; polymerase chain reaction (PCR) testing of a scab, vesicle…
- Management
First, for an otherwise healthy child with uncomplicated typical disease, routine oral antiviral treatment is not recommended; provide supportive care with fluids, gentle skin and nail care, itch…
- Complications
Bacterial superinfection with group A streptococci or Staphylococcus aureus is common in children and may progress to abscess, necrotizing infection, or sepsis.
- Prognosis
Chickenpox is self-limited in otherwise healthy children, who generally recover fully with supportive care alone.
- Prevention
Give two doses of live attenuated varicella vaccine to people without evidence of immunity: routine childhood timing is 12 to 15 months and 4 to 6 years, with catch-up doses separated by 3 months…
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