Hello Thank you for writing to HealthCareMagic I understand your concern Chickenpox (varicella) is a viral infection that causes an itchy rash with small, fluid-filled blisters.It is highly contagious to people who haven t had the disease or been vaccinated against it.Chickenpox is most easily spread from 2 to 3 days before the rash appears until all the blisters have crusted over and It usually takes about 10 days after the first symptoms before this happens (all blisters have crusted over). After you have had chickenpox, you aren t likely to get it again. But the virus stays in your body long after you get over the illness. Best Regards