This sounds exactlly like what my son has...and started at that age too. Its called eczema. The Drs. recommended Cetiphil - I used the baby wash and the tube of cream - and did that help a little, but he still had problems. (NO type of johnson/johnson, gerber or anything like that will help - infact it willonly make it worse)
The biggest help I found was going natural. Natural Products dont have the harsh chemicals in them that regular over the counter stuff do.
Visit your local health food store, or you can shop online at www.naturessunshine.com, and buy organic and natural. Get something that is for made expecially for
BABIES senstive skin...for my son Burts Bee's did the trick. I use their bar soap and appricot oil for a mosturizor. (and you can get that in other stores too, Ive seen in many pharmacies and Meijer and Target.)
Also, how often are you bathing him? It is VERY important NOT to bath his every single day. The water only dries out his skin more. You also may want to give him showers once in a while instead of baths. And a biggy is to be sure that you dry him VERY WELL...maily in joints.
And one more piece of advice that helped with my son was putting a cool mist humidifier in his bedroom.
I hope these ideas are useful for you and your baby...like I said they all really helped my son!
Good Luck.