Psoriasis causing allergic reactions?

Hi everyone, I developed extensive psoriasis out of the blue nearly a year ago now. A couple of months ago I had a pretty severe allergic reaction. At the time I thought it was to a type of sleeping tablet /I had started taking that night, but since then I've had a few more really severe reactions, with my face blowing up etc, with nothing to trigger them. Since I've never had allergic reaction like this before and I'm normally really good with allergies, I was wondering if maybe it's something to do with my psoriasis? If any of you have experienced something like this before I'd really appreciate your comments :)