It is hard to determine without more information, but some under the skin bumps in the area mentioned can be caused by a ganglion cyst. When in question, the best choice of action is to seek medical help from a professional.
If you wear a watch or a bracelet you might be having an allergic reaction. This is called contact dermatitis.If you have pets or go out in the woods you may have scabies. Scabies are parasites that burrow under the skin causing bumps and intense itching.
They are most likely some type of rash. Remember some rashes are good and some are bad. You might want to see a doctor if you are concerned. That is the best I can tell you. I get them too and I have been told not to worry about them.