Psoriasis and Migraine. In future?

Hi, My wife has been suffering with psoriasis and migraine at the same time (since 3 years, she is 25 years old). In cold, her psoriasis flare up, but right now the hands are fine. But there is in scalp. Also she has migraine, which affects her often, mostly twice or thrice a week. Currently she is not on any medication, she just sleeps in dark room when gets migraine attack, and use moisturizer for the psoriasis affected parts. I wanted to know long term affects having these two chronic disease at the same time. Also, I've heard the treatment of psoriasis is quite aggressive and can have lots of major side affects, can psoriasis be treated completely? Or if she doesn't get treatment, and just try to avoid flare up, maintaining healthy lifestyle, she will not have any complications in future? Thanks.