I said in a fun high pitch voice to my son as I poked his belly, "Is that your belly? That is one cute belly!"
She said, "No, look at his belly. He has a rash of sorts. I think he has Roseola."
I lift his shirt a little more, "OHHHH!"
She explained the illness that she thought he had and I immediately went home to reference my Mayo Clinic Complete Book of Pregnancy and Baby's First Year. And what do you know? She was right!
How to Recognize it. Your baby may be fussier than usual and have a fever of more than 101 degrees F for two to four days. When the fever subsides and the baby seems to be feeling better, you will notice a pink rash, mainly on the baby's trunk. The rash is not uncomfortable or itchy for your baby. You can't be sure the baby has roseola until the rash appears as the fever resolves. The rash usually lasts 24-48 hours.
What you can do? Other than treating for the fever, there isn't much you need to do for roseola.