I am experiencing rash on chest and rash (quality: itchiness, blisters, bumpy, red or bluish purple) .

Many possibilities: Rashes can be hard to figure out without looking at them. A rash can happen sometimes if a person's body is reacting to the germ causing viral or bacterial symptoms (sort of like an allergic reaction). Strep throat bacteria can make a toxin that causes reddish rashes. Allergy to certain foods or other substances can create rashes. Little blisters can be viral, bacterial, or contact dermatitis.