Suggest Treatment For Psoriasis And Psoriatic Arthritis

I am a 56 year old woman who has had auto-immune issues for over 10 years. One of the worst problems is the psoriasis on the palms and fingers along with psoriatic arthritis. However, one symptom I keep forgetting to mention to my doctors is the feeling like I'm being bitten all over my trunk by bugs. I have multiple issues and I'm wondering if this symptom may be the one symptom that can diagnose what is wrong with me.