For Past 10 Months Been Having Extreme Electic Shock Type

For past 10 months been having extreme electic shock type pain in left arm about 3" above elbow. It only lasts @ 30 seconds but then can come back a few seconds later. It feels like something is exploding in my arm. This same sensation has also started above my outside left ankle and above left knee. Few months ago it is also happening same areas on right ankle and knee and the left elbow shocks are getting much more intense and frequent. So far, my right arm is not affected. I am 57 yr old female and long distance runner with adult onset asthma (dx 3 years ago). Any ideas what this is?