Abstract
BACKGROUND: Diagnosis of psoriatic arthritis (PsA), in a period of 12 months from the onset of the first articular episode, permits of identifying the early form defined as "early PsA". The recognition of the disease in this phase leads to better outcome. The aim of this study was to identify peculiar clinical and/or laboratory findings that could be useful for the diagnosis of "early PsA". FINDINGS: Thirty-five patients with early onset of arthritis were observed. The following data were collected for each patient: family and personal history, physical examination, tender and swollen joint counts (TJC, SJC), tender entheseal count, presence of dactylitis and low back pain (LBP), and laboratory tests. Among the 35 total patients, 24 showed skin and/or nail psoriasis or a family history of psoriasis. The remaining 11 patients showed absence of concomitant or previous psoriasis and/or familiarity for psoriasis. The comparison between the two groups showed that patients with psoriasis had a significant presence of LBP, dactylitis and enthesitis than patients with psoriasis. CONCLUSIONS: The study confirms that the distinctive clinical findings of PsA is psoriasis, but also LBP, dactylitis and enthesitis have a relevant role in early identification. A low number of SJC and TJC are frequently observed in early phases of PsA than in other forms of early arthritis. These aspects could be mostly helpful when psoriasis is not detected or can follow arthritis in absence of familiar positivity, making difficult PsA diagnosis. In conclusion, careful medical history, clinical examination and first-level laboratory investigations are useful to characterize early phases of PsA.