-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