How do you know when shingles are no longer contagious?

No rash: As long as you can see the rash, it can be contagious. The blisters contain the herpes virus.

Herpes zoster: Shingles are not contagious to anyone who has had chickenpox, which is most of society. Once you have had chickenpox the virus is with you the rest of your life.

Shingles doesn"t : Cause shingles-it causes chicken pox. Shingles is contagious to people who have not previously had chickenpox, as long as there are new blisters forming and old blisters healing. Similar to chickenpox, the time prior to healing or crusting of the blisters is the contagious stage of shingles. Once all of the blisters are crusted over, the virus can no longer be spread & the contagious period is ove.