Chickenpox, Varicella


-Chickenpox is an infection caused by the varicella-zoster virus. 

-VZV is a double-stranded, linear DNA virus 

VZV infection causes two clinically distinct forms of disease: varicella (chickenpox) and herpes zoster (shingles).

-It is highly contagious, spreads readily by airborne droplets and by direct contact. 

Symptoms & Signs 

-Varicella most frequently occurs in children <10 years old but may occur at any age. 

-Varicella usually is a mild, self-limited illness in healthy children. 

-Fever, headache, malaise, papules, vesicles, crusts and scabs 

-It appears on the back of the head and ears, and then spreads centrifugally to the face, neck, trunk, and proximal extremities. 

-Vesicles are described as ‘dew drops on a rose petal’


-Diagnosis is clinically made based on history and physical examination

-Tzanck smear of the vesicle: Giant cells with inclusion bodies

-Histology: “Balloon degeneration” of cells with basophilic nuclei 


-For healthy children  ≤12 years, varicella is mostly self-limited; no antiviral therapy

-Immunosuppressed children and adults: antiviral therapy 

-Do not give aspirin because it is associated with the onset of Reye syndrome in the setting of a viral infection 

-Breastfeeding is encouraged in infants exposed to or infected with varicella. 


-A live attenuated varicella vaccine is available. 

-It is administered subcutaneously

-It is given in two doses; first dose at age 12 through 15 months, the second dose at age 4 through 6 years

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