When can a patient with a newly erupted varicella rash return to work?

The appropriate guideline for when a patient with a varicella rash can return to work is once all the vesicles are crusted over. This is because the risk of transmitting the varicella-zoster virus (the causative agent of chickenpox) to others greatly decreases when the vesicles have dried and crusted. Crusting indicates that the active viral replication has significantly decreased, and the individual is less infectious.

In contrast, being completely free of the rash or having just started medication does not guarantee that the risk of spreading the virus has diminished. Patients remain infectious until the vesicles have crusted, which can take several days. Therefore, returning to work before this criterion is met involves a risk of transmitting the virus, particularly to those who are immunocompromised, unvaccinated, or pregnant.