I have a rash under the breast very red at times and itchy also under one arm pit and groin and vagina hair area. Gets itchy sometimes sore?

Itchy Rash. Hello, some rashes can be location specific, however there are always exceptions. The areas your rash is located can frequently be caused by yeast or fungal infections. People with skin folds, diabetes, or who are immunocompromised are prone to these type of rashes. See a dermatologist if otc anti fungal cream doesn't help. Keep these areas dry and cool, open to air as often as you can.