as per your history it looks like psoriatic Arthritis only..just to rule out other Arthritis like gout or Rheumatoid arthritis do some blood investigations(haemogram,ESR,CRP,RA Factor,Sr.uric acid) as you said you have joint pain sience 12 months so just do both knee joint and hip joint xray to see any joint damage...for treatment point of view you have 2-3 options,whether to go with alopathy or Ayurvedic ,Homeopathy..in alopathy you have antiinflammatory medicines but those are just to reduce joint inflammation.and then some immunosuppressive drugs.I will suggest you to combine alopathy and Ayurvedic treatment..alopathy for joint pain and Ayurvedic for psoriasis..because if it is psoriatic Arthritis then we should deal with root cause first..