I have had an itchy, sore, bumpy red rash on my mid back area, below my bra line. i've had the rash for over a week. any idea what the cause could be?

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 a germ causing viral or bacterial symptoms. Allergy to any of a variety of substances can create rashes. Little blisters can be viral, bacterial, or contact dermatitis. A tender rash of tiny blisters or bumps in one section of an adult's body may be SHINGLES. Doctor can check.