If exposed to chicken pox (varicella), an unimmunized person may develop a rash
in 10-20 days.
The rash usually starts on the body or face and resemble a red spot, turns into a blister, then scabs over in a few days. The person is no longer contagious once all the blisters have scabbed. The illness usually lasts 7-10 days. Get a chicken pox shot if you have not had the illness.