Rash on my 8month old

Brooke

I took my eight-month-old to the pediatrician today for a check up because he has a rash on him which I thought was from an allergic reaction but the doctor said it was a virus and not to worry about it what this looks like something I am worried about I'm taking him tomorrow to get a second opinion. Anyone's LO ever have this? It's on his neck and stomach also