Little rash on parts of neck, back, stomach & under breast. itchy at times, put chrotozone cream on neck and helped that spot. what could it be?

Rash: If you are otherwise well, it may be something you were exposed to. Have your MD take a peak at it and give you an answer. All the best.

Could be: Many things... Heat rash, contact dermatitis from detergents, yeast infection, etc. I would suggest switching to perfume and dye-free detergent and bath soap, using the cortisone 1-2/day, and if it does not resolve in 3-4 days, have a doctor check it out.