Raised, skin-coloured bumps on sons abdomen?

Hi everyone! Im hoping somebody can help me a bit. My 3 year old randomly got this rash(?) In the summer. I thought it would go away, but it never did. Its very hard to see, and I only noticed it when I happened to touch there when putting lotion on. It doesn't hurt or itch he says. If I had to describe the feeling, it would probably resemble goosebumps, but it doesn't feel the same.

It has not gotten bigger and has stayed the same size since the summer. He does not have this anywhere else on his body, and I have no idea what caused it. Ive tried putting eczema cream and hydrocortisone cream on it, but it does not budge.

I'm not sure if he has any seasonal allergies, but he is allergic to peanuts.

Has anybody seen this before?

Thanks!