• What are the symptoms and manifestations of varicella?

    Varicella is caused by varicella-zoster virus (VZV). It usually occurs in childhood and is characterized by a generalized pruritic vesicular rash and fever.1

    Symptoms that develop prior to the onset of rash include malaise, pruritus, anorexia, and listlessness.1,2

    Skin manifestations in varying stages of evolution consist of maculopapules, vesicles, and scabs.1,2

    At first, the lesions contain clear fluid, pustulating and scabbing over a short period of time. Rash initially appears on the trunk and face, quickly spreading to other areas of the body. Successive crops of lesions generally continue over a period of 2 to 4 days. Crusts completely fall off within 1 to 2 weeks after infection begins and can leave a slightly depressed area in the skin.1,2

  • How is varicella transmitted?

    The most common mode of transmission of VZV is believed to be person to person from infected respiratory tract secretions.2 The virus is believed to replicate at the site entry in the nasopharynx and in regional lymph nodes.1 Varicella is usually contagious from 1 to 2 days before onset of rash until lesions have formed crusts.1

  • What are the complications of varicella?

    Adults may have more severe disease and have a higher incidence of complications.1,2 Potentially severe complications of chickenpox can occur, including bacterial skin infections, pneumonia, and encephalitis.1

Disease Information

DISCLAIMER: By clicking on the link below, you will be directed away from to another Web site. Merck does not review or control the content of the site to which the hyperlink connects; therefore, the hyperlink does not constitute an endorsement by Merck.

CDC Information

CDC=Centers for Disease Control and Prevention.

VACC-1167690-0001 01/17
1. Centers for Disease Control and Prevention (CDC). Varicella. In: Hamborsky J, Kroger A, Wolfe S, eds. Epidemiology and Prevention of Vaccine-Preventable Diseases. 13th ed. Washington, DC: Public Health Foundation; 2015:353–376. Accessed November 25, 2016
2. Whitley RJ. Chickenpox and herpes zoster (varicella-zoster virus). In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. Vol 2. 8th ed. Philadelphia, PA: Elsevier Saunders; 2015:1731–1737.