Final answer:
The incubation period for varicella is typically around 14 to 16 days, and individuals are contagious beginning 2 days before the rash develops until all lesions have crusted.
Step-by-step explanation:
The incubation period for varicella, commonly known as chickenpox, is typically around 14 to 16 days. Chickenpox begins with an initial infection of the respiratory tract, which after a period leads to the development of fever, chills, and a characteristic pustular rash.
This rash tends to start on the face, before spreading to the trunk and the extremities, usually affecting the trunk most extensively. Individuals can spread the varicella virus starting approximately 2 days before the rash appears and remain contagious until all lesions have crusted over.