I've Had A Rash On My Stomach Area - The

I've had a rash on my stomach area - the rash seems to be under my skin. I can see and feel lots of tiny bumps if I touch my stomach or look closely I don't have any itching or pain with this. I've had this rash for about 4-6 months. Tried exfoliating, over the counter creams & nothing seems to work. What could be causing the rash?