Early Recognition of Spondyloarthritis in Patients at Risk

Spondyloarthritis(SpA) is an umbrella term for a group of rheumatic diseases. It can manifest with pain and stiffness of the joints, tendons or lower back. Patients who suffer from psoriasis or inflammatory bowel disease (IBD) are at increased risk of developing SpA. In patients with psoriasis this is called psoriatic arthritis and in patients with IBD it is called IBD-related SpA. In __Part I__ of this thesis the prevalence and impact of SpA in these risk groups is described. We set up the SENSOR study to establish the prevalence of psoriatic arthritis in primary care. A special form of psoriatic arthritis is enthesitis, where the entheses are inflamed. We describe the results of an ultrasound study in enthesitis as well. For IBD-related SpA a systematic review was performed to establish the prevalence. We also looked at the impact of musculoskeletal complaints in patients with IBD. __Part II__ of this thesis focusses on awareness and screening. SpA should be recognized as early as possible to initiate adequate treatment early on. In order to achieve timely recognition, physicians should be aware of the increased risk in patients with psoriasis and IBD. The AppSpA study describes the current awareness in both general practitioners and patients themselves. Besides awareness, screening could also contribute to early recognition. For psoriatic arthritis multiple screeningtools have been developed. We tested these screeningtools in a primary care setting and compared the different screeningtools with each other

Prevalence of Psoriatic Arthritis in Primary Care Patients with Psoriasis

Objective To estimate the prevalence of psoriatic arthritis (PsA) in primary care patients diagnosed as having psoriasis and to estimate the prevalence of musculoskeletal symptoms in psoriasis patients in primary care. Methods We conducted a cross-sectional study in adult primary care patients with psoriasis. Responding patients reporting pain in joints, entheses, or the lower back were interviewed by telephone to determine eligibility and, if eligible, were invited for clinical evaluation. During clinical evaluation, skin, nails, joints, and entheses were assessed. Additionally, ultrasound of the enthesis was performed by an independent trained examiner if a patient had at least 1 tender enthesis (determined by the Leeds Enthesitis Index and the Maastricht Ankylosing Spondylitis Enthesitis Score). Patients who fulfilled the Classification of Psoriatic Arthritis (CASPAR) Study Group criteria were classified as having PsA. Results We invited 2,564 psoriasis patients from databases of 97 participating general practitioners. Of 1,673 responders (65.2%), 841 (50.3%) were willing to participate. A total of 823 patients (32.1%) reported having musculoskeletal symptoms; 659 of these patients were determined to be eligible, 524 of whom were clinically evaluated. We identified 64 cases of established PsA and another 17 cases of newly diagnosed PsA, leading to a prevalence of 3.2% (95% confidence interval [95% CI] 2.5-3.9) among psoriasis patients in primary care. This prevalence would increase to 4.6% (95% CI 3.8-5.4) if PsA cases based on enthesitis were also taken into account. Conclusion Among psoriasis patients in primary care, the prevalence of PsA is conservatively estimated to be 3.2%, increasing to 4.6% if enthesitis is taken into account. The prevalence of musculoskeletal symptoms among psoriasis patients is comparable with the prevalence of musculoskeletal symptoms in the general population