The incidence of enthesopathy as an early manifestation in psoriatic arthritis

Abstract

Introduction. Psoriasis is a common chronic immune-mediated skin disease that affects ~2% of the population. Psoriatic arthritis may be present in different clinical forms whose major features are synovitis and/or enthesitis. Enthesopathy is one of the features characterizing patients with spondyloarthropathies. Its diagnosis is usually based on clinical symptoms such as the presence of calcaneal pain or tenderness at the insertion(s) of ligaments. Aim of study. The importance of enthesitis as the key pathological lesion underpinning the pathogenesis of psoriatic arthritis (PsA) has been increasingly recognized. Studies for more than 3 decades have shown a high frequency of osseous and entheseal abnormalities in patients with psoriasis without clinical signs of arthritis. From a clinical viewpoint, about 10% of patients with psoriasis develop PsA over a decade, so there is a need to better define predictive factors for the identification of future PsA in patients with psoriasis. The ability to accurately predict development of PsA in subjects with psoriasis could have implications for prevention of the morbidity associated with PsA and also for studies aimed at elucidation of the early phases of disease. Methods and materials. This is a review of articles of clinical studies, trials, bibliographies and articles from databases like JRheum, Europe PMC, Oxford Academic, BMJ. Results. Mean GUESS (Glasgow Ultrasound Enthesitis Scoring System )score was significantly higher in patients with psoriasis as compared with controls: 7.9 (0.6) vs 2.9 (0.3); p<0.0001. In particular, the thickness of all tendons examined was significantly higher in cases than in controls (p<0.0001), as well as the number of enthesophytes in all sites examined. In both cases and controls, the GUESS score was directly correlated with age (r = 0.22; p = 0.008), body mass index (r = 0.23, p = 0.0067) and waist circumference (r = 0.17; p = 0.02). In contrast, the GUESS score was not correlated with the duration and severity of psoriasis according to the Psoriasis Area and Severity Index (r = 0.03; p = 0.8) and body surface area involvement (r = 0.07; p = 0.6). Conclusion. Entheseal abnormalities can be documented by ultrasonography in clinically asymptomatic patients with psoriasis. These findings could be related to a subclinical entheseal psoriatic inflammation. We suggest close follow-up of patients with psoriasis with entheseal abnormalities for early diagnosis of psoriatic arthritis.