Red itchy rash under breast and groin area it looks like sun burn with bumps. I'm itchy all over but no rash other then those areas. What can this be?

Yeast infection? If you are overweight, the areas under the breasts, the love handle, and the groin are more susceptible to candida infection. If this applies to you, try to keep these areas dry by using antiperspirant . In the meanwhile try some anti-fungal cream on the areas for a few days. If still not improved after a week, see you doctor. For overweight people, losing some weight should be a long-term goal.