A.K.
I have this same condition on my arms, legs and stomach (it got so much worse during my pregnancy.) The products I've used that I've had the best results with are Aveno daily calming lotion, Cetaphil lotion and Alba pineapple face wash (it contains pineapple and papaya extracts which help dissolve the keratin).
since he's so young just washing and moisturizing is probably all you can really do. However once he's older and his skin isn't so sensitive he will want to exfoliate every day. I use a loofah (this is serious loofahing, not just a light scrub) then I wash all over with the Alba face wash. While I'm still soapy I loofah again then rinse. I use the Aveno lotion right out of the shower and the Cetaphil during the day. Nutrigena also makes a nice body oil that I've had good results with but it's a little messy.
Also I use a home microdermabrasion (sp?) kit. It really helps get rid of the dead skin that locks in the keratin. But it takes time so I only do it about once a week.
Once you get rid of the bumps you can usually get the redness to lessen with hydrocortizone. Cordaid makes one with aloe that isn't as drying but here again you'll probably want to wait until he's older for that.
Good luck.