What are Red raised bumps on body that come and go?

This sounds like it could be hives, especially if they itch. Hives will pop up anywhere on the body, itch (quite severely, at times) then go away, then recur on and off. They can vary in size and shape, from small bumps all the way to large raised welts. While some may not itch a lot, for others the itching can be quite intense at times, causing you to want to scratch your skin off!

The cause of hives can be an allergic reaction, or they can be caused from stress, or there may be no obvious cause for them. The good news is they are easily treated, but you need to see a doctor for a diagnosis and prescription. They are not contagious, so you don't have to worry about anyone else in the family catching them.