Skin Problems. pLZ HELP

Kirby • 22. Can't wait for my baby boy to get here! Hurry up August!
So I took my son to the doctor about a week ago because he was suffering horrible constipation and started to break out badly. That's when we learned he had a milk protein allergy and had to be put on soy formula. The doctor also said his bumps would go away in a couple days. Wel here we are days later and his constipation has gotten much better but his skin seems to have gotten worse. It is super dry and the bumps have multiplied and are not on his face chest arms and legs. They don't seem to cause any pain so I wanted to see if anyone else might have an idea of what they are before I take him back to the doctor.