The marked difference between these two disease conditions is that Psoriasis has well defined dry scaly patches, but in Eczema the skin is red, cracked but not scaly in nature it can be blistered or pus-oozing.
Along with medicines Diet helps a lot in the long run. Working on your stress as stress leads to flare ups. Avoiding alcohol and smoking also helps.
No, it is not contagious at all. It is not and it was never like You touch it you get it. This is a very bad myth and affects a Psoriasis patient socially.
The cause of psoriasis is still unknown but some factors are considered as causative factors like:-
Family history :- Psoriasis is a disease which passes on. If your one parent has psoriasis you are at a risk of having it but if your both parents have psoriasis you are at a higher risk of having it.
Stress :- a strong mental or emotional pressure can cause it.
Smoking and Alcohol :- these two factors are known to cause Psoriasis and also disrupt the treatment of an existing as they make medications less effective.
Injury:- injuries are seen to trigger Psoriasis.