Diagnosed With Psoriasis. Flared Up After Using Medication. Causing Stiffness In Both Knees. Psoriasis Arthritis?

hi. i have recently been diagnosed with psoriasis . This was done with a visit to my local GP a couple of weeks ago. At the time i had a couple of small areas on my right hand and wrist which were causing irritation. I also had a couple of areas on my left forearm which were causing me concern. Two of my fingers on my right hand were also affected. Unbeknown to me, my knees also had psoriasis. Since using the medication , it seems that this has only encouraged the psoriasis to flare up even more in the areas i have mentioned (apart from the knees). I now have two large red areas on my right hand and wrist, although it does not look as raw as it did previously. Although it still looks as though it is spreading slowly, the skin is peeling away around the edge of the affected areas. On my left forearm, the areas look as though they are slowly scabbing over. The two fingers on my right hand are also red in colour, but peeling at the edge. As this has only developed in the last month or so, does this sound like the psoriasis is clearing? Also, i do suffer from quite a bit of stiffness in both of my knees. I wasn t aware that you could suffer from psoriasis arthritis!