RASH THAT DOES NOT ITCH

I'm a 57 year old female with no skin problems with the exception of this annoying rash on both arms that DOES NOT itch.  After I shower, the red color really pops out.  It looks terrible when I wear anything sleeveless.  I've had this rash for almost a year so it's not fading or going anywhere.  Sometimes I get a rash on my thighs, but it will eventually go away, but the rash on my arms are here to stay.  Does anyone else have this same problem, and if so, have you found any miracle treatment?