20 doctors weighed in:

How long is chicken pox contagious? 

20 doctors weighed in
Dr. Martin Raff
Internal Medicine - Infectious Disease
9 doctors agree

In brief: Varies

Patients (usually children) are infectious to others for roughly 2 days before the blisters occur and then until the blisters have formed scabs covering them completely, about 4 to 5 days.

In brief: Varies

Patients (usually children) are infectious to others for roughly 2 days before the blisters occur and then until the blisters have formed scabs covering them completely, about 4 to 5 days.
Dr. Martin Raff
Dr. Martin Raff
Thank
Dr. Mark Diamond
Pediatrics
7 doctors agree

In brief: Around 10 days

Generally 1-2 days prior the onset of the rash.
Then until there are no new ones and all the old lesions are scabbed over.

In brief: Around 10 days

Generally 1-2 days prior the onset of the rash.
Then until there are no new ones and all the old lesions are scabbed over.
Dr. Mark Diamond
Dr. Mark Diamond
Thank
Dr. James Ferguson
Pediatrics
4 doctors agree

In brief: School requirements

We acknowledge that these kids are contagious before the spots appear, for 1-2 days.
This makes containing spread problematic to start. We try to exclude them from school or public places to prevent spread. The general rule is to exclude them until the last new spot has crusted and dried, or at least 7 days from the first spot.

In brief: School requirements

We acknowledge that these kids are contagious before the spots appear, for 1-2 days.
This makes containing spread problematic to start. We try to exclude them from school or public places to prevent spread. The general rule is to exclude them until the last new spot has crusted and dried, or at least 7 days from the first spot.
Dr. James Ferguson
Dr. James Ferguson
Thank
Read more answers from doctors