Hi, I Have A Cold Spot Sensation On My Inner

Hi, I have a cold spot sensation on my inner left leg. This is not the first time I've felt this. The first time was a little over a year ago. I do have frequent lower back pain. They have found nothing wrong there by X-ray. But MS does run on my fathers side. I'm not sure if it can be caused by my lower back, MS, or certain antidepressant that I'm taking? I'm really considering on seeing my doctor about this.