exercise

Can anyone tell me the effects of exercise on psoriasis and the difference between psoriasis and eczema? I ask about exercise because I notice my psoriasis is mainly on my arms and legs. my back is a little bit itchy but generally my trunk and head in particular is clear. This gives me the thought that circulation improves it. I rarely hear of psoriasis on the head and it is known to have a good circulation compared with the rest of the body, Thereby exercise should be good for psoriasis as it is good for circulation? Yes or no? I am also confused since I read that beta blockers like Bisoprolol can cause psoriasis and since I was taken off this about 4-6 weeks ago the psoriasis on my hands has improved a lot. However several GPs in my old practice never told me what it was and I was eventually told by a hospital junior doctor as a passing comment when seeing him about something else. However now a young Doctor at my new GP surgery sees photos sent by e mail of parts of my body and says it is eczema . What is the difference? She is going to send me strong steroid cream that I am told I have to be careful with. Difficult life?