What Causes Itchy Bumps On The Legs,shoulders And Finger?

i have itchy small red lumps on my legs and shoulder and finger. but mainly my legs. I have had them for about 4 days and thought they would go but they are just more itchy. They looks like mini spots but lots of them? I also have itchy nipples and have no scratched of the skin on them and they stung a lot too. I also have lumps on my tongue?