811 W. John Street, Yorkville, IL 60560
For 24/7 Mental or Public Health Emergencies, call 630-553-9100
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Chickenpox (Varicella)



A very contagious mild to moderately severe disease caused by the varicella-zoster virus (VZV). It can affect all ages, but it is most common in children.

Signs and Symptoms

Early signs and symptoms include sudden onset of slight fever, a vague feeling of body weakness or discomfort (malaise) and loss of appetite. Within 24 hours an itchy rash begins in crops on the arms, legs, trunk and face. The rash breaks, drains and forms scabs in 3 to 4 days. The skin rash goes through typical stages: flat red spots, small blisters and crusting blisters. Lesions commonly occur with several stages of maturity present at the same time. They tend to be more abundant on covered, rather than on, exposed parts of the body. May appear on the scalp, high in the armpit, on mucous membranes of the mouth, upper respiratory tract and on the conjunctiva or they may be so few as to escape observation.

Incubation Period

Signs and symptoms occur anywhere from 10 to 21 days following exposure.

Mode of Transmission

Chicken pox is contagious usually one to two days prior to the appearance of the lesions and until the lesions have crusted. Transmission is directly from lesions or respiratory droplets i.e.: coughing sneezing etc. Infected individuals should remain isolated from others until all lesions have dried to crust stage. Immune suppressed individuals should be isolated from a person infected with chicken pox, as they are at high risk for complications, should they acquire the infection.

Period of Communicability

Chickenpox is contagious usually one to two days before the onset of rash and ends when all lesions are crusted, typically 4-7 days after onset of rash in immune-competent people, but this period may be longer in immune-compromised people. Patients with herpes zoster are contagious while they have active, vesicular lesions (usually 7-10 days).

Preventive Measures
  • Varicella Zoster Vaccine (VZV).
  • Use Universal/Standard Precautions. Good handwashing and covering of mouth and nose when sneezing and coughing, reduces spread of infection
  • Varicella Zoster Immune Globulin (VZIG) is effective in modifying or preventing disease if given within 96 hours after exposure.
Implications for School

Exclusion from school is required until student is non-communicable, which is six days after the first crop of scabs appeared or when all scabs are dry and when there is no liquid in the lesions. Letters should be sent home to the parents of the other classmates and staff who are immune suppressed or who have not had the Varicella vaccine when a case of chickenpox has been reported. Any cases of chicken pox are to be reported to Student Health Services #____________. Students must have a doctor’s note to return to school.

Serving the Residents of Kendall County Since 1966
811 W. John Street, Yorkville, IL 60560   •   630-553-9100