My baby last 3 days with high fever now has red little bumps what is it?

Roseola?: Without actually seeing the rash and examining the baby, it is very difficult to say for sure what the rash is. However, in a baby less than 2, if they've had fever for a couple of days and then when the fever breaks develop fine red rash, sounds like roseola (also known as 'baby measles'). If it doesn't fade n next few days, or there are other associated symptoms, then need to see your peds doc.