My 8 month old has a rash

Hello, my son is a little over 8 months, and about two months ago he had a few red spots on his tummy area. I asked the pediatrician and he said it was normal, maybe a little bit of ezchema. He told me to put Aquaphor on it. Well i did and now being a couple months later, the redness has spread. Its spotty from his tummy area, some on the back of his arms and legs, and a little bit on his back. Some days its seems it has gone away, and days like today, it is bright red. I have tried many things. oatmeal baths and lotions, several OTC skin care creams for babies, and nothing works. Its stays in the same spots and spreads throughout. Not one spot  heals. It almost looks as if its going to scar his skin. The days that it looks like its almost disappeared, you can see some spots where his skin may look lighter, as if its scared. But it keeps coming back. Im going to make an appt again.  Oh, and sometimes my son tugs at his shirt as if it itches him. In the mean time, and ideas on what it could be?