Skin problems

When I am sitting for long periods of time I start to get stinging patches on my skin. The areas that sting are usually on my wrists, stomach, and tops of my legs. Ocassionally my face stings a litle bit as well. I have noticed that coffee and alcohol definatley make it worse. If I get up and move around sometimes it does get better, but it usually comes back again. My question is what could be causing this and what should I do? Thanks for your help. Tweet