I suffered from psoriasis just before my parents were divorcing. If your parents have 'been through a lot' it's possible you're shouldering a lot of the effort and coming under some personal stress. Like exzema it has strong psychological links, and it manifests your stress in the red patches. When I stopped getting in the middle of my parents, mine cleared up completely. In times of major stress, it flares up a tiny bit still though.
Go to the doctor, he can prescribe creams and ointments. Bath oils like oilatum work well (can't remember the one i used, it was similar to oilatum and worked wonders - will have a check). But try and sort out the psychological stuff too (if it's only flaring up now it might well be connected to this). Try to find ways to relieve your stress or lessen the burden of responsibility you carry, and if possible maybe look into therapy.
Good luck!