I just developed the exact same thing about a week ago. Mine started with a LARGE rash on my forearm, and the next day I had the large-ish bumps on my elbows. All are very itchy and annoying. The elbow ones look GROSS!
I have always had sensitive skin and had horrible heat rash all over when I was a kid, so I can't say I was really that surprised. Not sure what these are from, but I am guessing the drastic change in weather...I live in Michigan, so it goes from cold to hot, back to cold and rainy a lot. Not sure where you live, but could that maybe have an effect on your skin too?
I have been using Gold Bond medicated anti-itch cream, which has helped significantly on the forearm. I am hoping it will do the trick on the elbows as well, but possibly takes longer because the skin there is thicker...
Good luck, and let me know if anything works for you. I will do the same.