Pressure point Psoriasis

I am a 73 yr old male ;I have suffered patchy psoriasis for more than 40 years, but in the last year this has settled into a fixed pattern that matches all the pressure points....bedsore contacts... shoulders, ribs, hips, outer leg and ankle. Is this common ? and have sufferers found effective responses , I worry that deeper bedsores may develop, which probably compounds the problem !