My baby is 22 weeks old and has gotten a rash on his cheeks and nose, but is acting normally. What can we do about it?

If he has a fever... ...It could be a virus, and you should see your pediatrician. If no fever it could still be a virus, or he could have come in contact with something he's allergic to, possibly something floating in the air like dust or pollen. You can try some 1/2% Hydrocortisone cream, but if the rash persists you'll need to see your doctor.