Why Am I Experiencing Itching And Welts In My Left Leg Along With Pain And Tenderness?

I am experiencing itching and welts in my left leg. What alarms me is that there is pain and tenderness when I touch one welt located in my calf. Also the area is red and warm - perhaps from my scratching. Could it be dvt of the leg? Should I go to the hospital now? The itching started yesterday evening. I need your advice. Thanks in advance