I'm no doctor, but it sounds to me like a virus my kids had called "Mollescum Contagiosum". I know, it sounds like it's out of a Harry Potter film, but it's basically a kind of wart thing. Both my boys had it and it is VERY common. Picked up at public pools and on play grounds and such. Unfortunately doctors don't seem too concerned with it because it's not harmful in any way, it's just ugly. So there really is no cure. Your pediatrician will tell you not to worry and you child will grow out of it. The problem is that it can hang around for years. In the meantime you have to deal with stares and odd looks from other concerned parents and even though it's not contagious - it doesn't make you feel any better.
I did take both my boys to a pediatric dermatologist who used "beetle juice" (I know - we're back to the harry potter film) on the spots. It has a clinical name, but most doctors and dermatologists will know what you're talking about. It's put on the spots and left to dry. You wash it off after 4 hours and then the bumps will blister, scab over and fall off. There are two problems with this remedy. My son did complain of some discomfort - a bit of burning. This did not last after we bathed him to wash it off. The other problem is that if it has spread to lots of areas it is very hard to treat this way. Most dermatologist will only treat a small area and by doing that - you get rid of the problem in one spot, go back to the dermatologist in a week or so to treat another, but then run the risk of it spreading to an area that you've already treated. And it could wind up being a viscous cycle.
We did find an independant pharmacy in Laguna Niguel that made a "glucose wart cream" for us that finally got rid of the problem with no pain and could treat all the areas, but this "wart cream" is not over the counter and I don't where you're located. I would be happy to talk to you further in regards to trying to get this to you, but you really should talk to a dermatologist first to be sure that is the problem. Maybe there have been improvements in a remedy since my boys had it. This was about a year ago. Good luck to you and don't be fooled by the treatments you'll find online for Mollescum Contagiosum. I tried them all and they did nothing, but cost me money.