Like to know what my rash under upper arms under and in between my legs, larger red spots going smaller down arm. Not itchy and my breasts feel double the size at the same time? No fever?

"Rash" ?'s. Areas of heavy perspiration (underarms, genital areas) will create skin disorders, especially if you have gained weight. See a dermatologist for an exam, as there are many kinds of skin eruptions which can be treated easily. .