The rash usually turns into blisters, which dry and become scabs in 4 to 5 days. The symptoms of chickenpox may resemble other medical conditions. Always consult your physician for diagnosis. Chickenpox is contagious one to two days before the appearance of the rash until the blisters have dried and become scabs. Once infected, chickenpox may take up to 10 to 21 days to develop.
Diagnosis usually involves a medical examination.
Since 1995, a chickenpox vaccine has been available for children 12 months of age and older. Adolescents and adults who have never had chickenpox can also get the vaccine. The vaccine has proven very effective in preventing severe chickenpox. The CDC Advisory Committee on Immunization Practices, the American Academy of Pediatrics, and the American Academy of Family Physicians recommend that all children be vaccinated with the chickenpox vaccine between 12 and 18 months of age. Sometimes a secondary case of chickenpox does occur.