Diagnosis and evaluation of psoriasis and psoriatic arthritis

The most critical element in the diagnosis of psoriasis and psoriatic arthritis (PsA) is understanding that it is a clinical diagnosis. In a patient with joint pain and/or swelling the differentiation of PsA from other types of inflammatory arthritis may be a central element in treatment decisions. Unfortunately, there are often no specific laboratory or radiographic findings that reliably confirm this challenging diagnosis.