Varicella (Chickenpox) Isolation Period
In healthcare settings, persons with varicella should be excluded from work or kept in isolation until all lesions have dried and crusted. [1] Varicella is considered contagious from 1–2 days before rash onset until all lesions have crusted. [2]
Isolation Start Point
Isolation/exclusion should begin at rash onset, including the period during which new lesions are developing. [1]
Contagiousness Endpoint
The discontinuation endpoint is complete crusting of all lesions. [1]
Exceptions for Vaccinated Persons
Exclusion can be discontinued for vaccinated persons who do not develop vesicles when no new lesions appear within a 24-hour period. [1]
Practical Duration Estimate
Chickenpox typically lasts 4–7 days, which often aligns with the period required for lesions to crust. [2]
Infection Control Context
Isolation guidance is part of CDC infection-control measures for varicella in healthcare settings and is used to prevent transmission from vesicular lesions. [1]