I get a skin rash on my lower legs after I stand on my feet allday long. What should I do?

Capillaritis. Minute red dots that appear after standing all day is called a capillaritis. Do you have varicose veins? That could also contribute to your problem.
Swelling. This may relate to swelling of your feet from standing all day. The swelling of your legs can extend the skin and irritate it. Treat the underlying cause of the swelling and this may help with the rash due to standing all day. Hope this helps.
Leg rash? Is it a rash? Or skin blotching? Is it under the skin or is it rough to touch? Do you have varicose veins? It could be from blood pooling from constant standing. Elevate your legs once at home.