I have had very itchy welts on my left forearm for 3 1/2 months now. have been to 2 different doctors but neither one could figure out what it is. occasionally welts will appear on other random and scattered parts of my body then go away?

Hives can be difficult, because a million things can cause them, and it can be a real chore to figure out what is causing yours. You need to do some detective work -- what did you eat right before the most recent outbreak? Any new medicines or vitamins? Have you been sick? A dermatologist would be your best option if this has been going on for several months.