Answer:
If one member of your family had psoriasis or still has then it is very probably to "get" psoriasis some day too. Actually, a person doesn't get psoriasis because it is written in the genetic information so you can have it since the day you are born...it is not contagious so if your question was meant to mean if a person can get psoriasis just by touching a person with this condition then i can assure you that's impossible...if your question refers to triggers for psoriasis then i can tell you that stress is the most important in the list..then it comes streptococcus infections..in my case, i inherited the disease from my grandma and the triggers were stress and streptococcus infection.