chickenpox

A common contagious viral infection that is caused by the varicella-zoster virus and is characterized by low fever and itchy rash. The chickenpox rash begins as red spots on the chest and back that then turn into small fluid-filled blisters. After a blister bursts, a dry crust forms. New pox continue to appear for approximately five to seven days after the rash first appears. A person is considered contagious until all the blisters have burst and dry crusts have formed.