Blochy, non-itchy or painful pink/red spots all over body?

[MissPeppermintTea]

I started getting this rash when I was fifteen, back then it just started out around the side of one of my breasts. It was just a small spot or two but it never really went away. I've noticed over the years that the rash would multiply.  I'm twenty three now and the "rash" has spread: it's on my chest, my shoulders, the back of my shoulders, my neck and is slowly starting to climb to my face. Like I said, it's not itchy or painful. It's not raised nor does it feel dry. It feels exactly like the rest of my skin. Wearing jewelry does seem to at times make it worse, so I stopped wearing any in the hopes it would go away - it hasn't.   I'm completely stumped.

The only thing I can say that might be helpful is around the time I got this rash, the RV park my parents and I were staying at for a few months was spraying pesticide around and when I got this rash, according to my mother, a family friends dachshund got a rash very similar to mine.    I'm not on any medications, nor was I before the rash or during the rash and haven't been aside from like a strep throat a few years ago, have been medication free. I've changed detergents, I've changed dryer sheets, I've tried different kinds of lotions and nothing really seems to help. Sometimes the rashes will fade almost completely away and then they'll come back.

Have no idea what to do. Anyone have any ideas? I can upload pictures upon request.

TL;DR
Red and pink spots covering entire body. Not painful, not itchy, not raised. No bumps and rash doesn't feel dry or scaly. I'm not sore, weak, tired, etc. just a normal girl with a weird rash that's spreading all over her body. Jewelry seems to aggravate it so stopped wearing it, still gets worse and still spreads. No idea what it is.