Chickenpox (Varicella)

Diagnosis

Your doctor usually can tell whether someone has chickenpox over the phone, especially if that person has not had the chickenpox vaccine or the chickenpox disease before. If your doctor is not sure, he or she may want to look at the skin rash. Although it also may help to know whether the patient has been exposed to someone with chickenpox, this is not necessary to make the diagnosis. Special blood tests, such as the FAMA test (fluorescent antibody to membrane antigen) and the ELISA (enzyme-linked immunosorbent assay), are also available, but they do not need to be done in most patients. Sometimes your physician may scrape a chickenpox blister to examine under the microscope.

Expected Duration

Chickenpox blisters form over a period of 3 to 5 days and then crust over during the next 7 to 10 days.