My 4 Month Old Baby Started Getting A Rash About

My 4 month old baby started getting a rash about 2 weeks ago. It does not itch or seem to bother him. No fever with it. He had a clear runny nose for a few days when the rash first started to show up. Began on his legs and face and now on arms and fingers too. They are just Red splotches maybe the side of a pea and very slightly raised. They will show up for a couple of days and then just go away. He probably has 4-5 on his face, 10 on arms and 10 on legs. I have recently started giving him rice cereal mixed with formula.