bumps on skin

My son is three years old and has no allergies I am aware of and we are from SK, Canada.  About two and a half months ago i noticed ten or fifteen bumps on the right outer arm just above the elbow.  When I noticed this I took him to a doctor who happened to be a new one from South Africa.  When she looked at his arm she was CERTAIN it was scabies (which freaked me out).  I second guessed that a little because the bumps didn't seem to be itchy or bother him from what I could see.  Never the less I treated him with what she gave me which was actually (selenium sulfide)  selsun blue shampoo and hydro-cortisone cream for a week.  This treatment didn't see to help what so ever, so I went to see my doc who completely disagreed with it being scabies, she thought maybe it was eczema or a viral infection which looked nothing like what he has. She gave me a steroid cream to put on it but that doesn't really help anything go away.  The bumps started out as just skin toned bumps then turned red, scabbed and later the went away but left pigmentation loss where the bumps were.  Later i noticed them scattered down his right forearm and in his left hand on top of his knuckles  So now I was scared maybe it was scabies so i took him back, and this doctor had to idea brought out a dermatology atlas and we found only one thing in there that was close but who knows:(  My son is not getting any better so I hope you can help.  I was wondering could it be some sort of chemical under his skin trying to get out?   the bumps do not look like they have a center at all, but I did notice on bump out of all of them had a tiny scab or whole right in the center.