Which intervention is appropriate to prevent spread of symptoms until a specific day?

• A. Isolate until fifth day of rash
• B. Isolate for one more day
• C. Wear no mask
• D. Share utensils with others

Answer: (A)

Contagiousness is highest during the period around the rash, so the goal is to keep others safe by staying isolated until that contagious window has passed. For illnesses that present with a rash, such as varicella (chickenpox), a person is typically contagious from about one to two days before the rash appears until all lesions have crusted, which commonly occurs around the fifth day after the rash begins. Keeping someone isolated until the fifth day of the rash covers the most infectious phase, reducing the chance of spreading the illness to others.

Ending isolation earlier would risk transmission while new lesions or uncrusted lesions may still be present. Wearing no mask doesn’t address the contagious period, and sharing utensils would spread the infection directly. Thus, isolating until the fifth day of the rash best prevents further spread.