Acute, highly contagious viral infection

Same virus that causes chickenpox, which is thought to become latent until the sixth decade of life or later, causing herpes zoster (shingles)

Occurs through direct contact (primarily with respiratory secretions, less commonly with skin lesions) and indirect contact (airborne)

Congenital varicella possible in infants whose mothers had acute infections in first or early second trimester

Neonatal infection rare, probably due to transient maternal immunity

Most commonly occurs in children ages 5 to 9, but may occur at any age

Affects all races and both sexes equally

Seasonal distribution varied; in temperate areas, incidence higher during late winter and spring

Also known as chickenpox

Localized replication of the virus occurs (probably in the nasopharynx), leading to seeding of the reticuloendothelial system and development of viremia.

Diffuse and scattered skin lesions result with vesicles involving the corium and dermis with degenerative changes (ballooning) and infection of localized blood vessels.

Necrosis and epidermal hemorrhage result; vesicles eventually rupture and release fluid or are reabsorbed.

Incubation period lasts 10 to 21 days.

Infection is communicable from 48 hours before lesions erupt until after vesicles crust over.

Varicella-zoster herpesvirus