Background/Purpose: Psoriatic arthritis (PsA) is an inflammatory musculoskeletal disease associated with psoriasis. Over the past several decades it was recognized that PsA is more common and more severe than previously thought. It has also been noted that patients who present earlier to a rheumatologist do better. However, whether patients have been treated earlier and more aggressively over the decades is not clear. The objective of this analysis was to describe the demographic, clinical features of inflammation and damage, as well as comorbidities and therapies provided over 4 decades in a single clinic.

Methods: A special clinic for psoriatic arthritis initiated in 1978. Patients are included if they have psoriasis and an inflammatory arthritis and other forms of arthritis have been excluded. Patients are followed at 6-12 month intervals according to a standard protocol which includes demographic, clinical, and laboratory evaluations and detailed drug treatment. Radiographic assessments are done at 2 year intervals and include peripheral joints according to the modified Steinbrocker, and axial disease according to NY criteria. Patients who entered the cohort in the past 4 decades were included. Descriptive statistics are used.

Results: Over the 40 year period 1428 patients were entered into the clinic and recorded in the database. 635 females 793 males, mean age at diagnosis of psoriasis 28.8 and at PsA 38 years. Information on the clinical, laboratory, radiographic and therapeutic features is provided in the table. As can be seen age at diagnosis remains in the mid-40s, and disease duration of psoriasis remains similar across the decades. However, PsA disease duration has decreased over the decades, suggesting that patients are referred earlier in their course. Patients presented with similar degree of disease activity but less patients had evidence of damage at presentation in more recent decades. This is also reflected in the radiographic evidence of damage and the functional class ¾. More patients have comorbidities in more recent decades. While NSAIDs use remains stable, there has been an increased in use of DMARDs, particularly biologics. This is partly related to the availability of the drugs since 2000, but also to the more aggressive approach to the management of the disease.

Conclusion: Over the past 4 decades similar patients have been admitted to the PsA clinic.  However, patients seem to be referred earlier in the course of their disease, and this is reflected in less damage both clinically and radiologically. This may also reflect the increased use of DMARDs both conventional and biologic in this patient population. Education regarding the severity of PsA and the need for early diagnosis and treatment is working. However, further efforts are required to have patients with PsA diagnosed earlier and treated more aggressively to prevent untoward outcomes.