Hi i am not sure if i am much help as i seem to be going thru the same thing as you ,my pimple like rash started a few months back now its spreading all over my chest , my rash is not realy itchy, I went to one doctor who said its exzema and prescribed cortisol cream which i was not keen to use as it has to many side affects , so i went for another opnion.
The female doctor told me i have pimples due to my hormones changing, ()I told her I noticed when I am sleeping and wake up my skin feels oily on my chest, she said its due to heat and sweat combined so I was told by her to just keep it clean and dry now my rash seems to be spreading to under breasts and tummy what do i do now go for another opinion and get a third diagnosis
Are you going thru menapause as well ? This could be a reason for your rash.....good luck