Global prevalence of psoriasis is ranging from 0.91 % to 8.5 % . Exact numbers are missing for Slovakia. 1-5% range is the most probable while 2 % is also mentioned as an average prevalence for the European population. There is approximately 110 thousand patients suffering from psoriasis when extrapolating from total population of 5.5 million . Extracutaneous manifestation is observed in 11–30 % of patients after years of solely skin symptoms presentation [3, 4, 5, 6].
Objective: To estimate prevalence of psoriatic arthritis among psoriatic patients population visiting dermatology out-patient irrelevant of the disease duration and the treatment regimen. To compare the sensitivity of both tests (ToPAS and PASE) used, evaluate possible PsA risk factors.
Methods: This was a prospective, non-interventional, epidemiological, observational study conducted using a survey administered to psoriatic patients by their dermatologists. 10–20 consequent outpatients with psoriasis in each center in 43 regional dermatology officies were screened for the presence of extra-cutaneous symptoms (i.e. joint pain, enthesitis, dactylitis, nail involvement) using questionnaire, developed specificaly for this study, and by the PASE and ToPAS questionnaires. Patients without personal history of PsA and „positivity“ of PASE and/or ToPAS were sent to the center for confirmation / exclusion of the diagnosis by applying CASPAR criteria. Outcomes were statistically processed.
Results: 177 (21.8 %) of total of 831 psoriatic patients had PsA. 9 of 177 (5.35 %) has been newly diagnosed. There was almost equal number of men (50.5 %) and women (49.5 %).
Plaque psoriasis has been most frequent type – 76.9 %. 43.2 % of PsA patients reported the onset of the disease after 40 years of life. Time interval between onset of psoriasis and PsA has been less than 10 years in 20.2 %, 10–20 years in 20.8 % and more than 20 years in 16.1 %. Most frequent co-morbidity in the study population was hypertension 23.2 %, asthma 3 % and diabetes 2.4 %. Average value of BSA and PASI was higher in PsA vs. non-PsA group: 24 vs. 20 and 10 vs 9, respectively. The sensitivity (72.6 % vs 58.9 %, P=0.01) and specificity (81.3 % vs 80.5 %) of ToPAS was higher compared to PASE.
Conclusion: 21.8 % PsA prevalence in psoriatic population in Slovakia is within the range observed in other studies. ToPAS test showed comparable results in terms of specificity, but significantly better results in terms of sensitivity and its early application should be of major importance because of the diagnostic process acceleration. The effect of an early diagnosis on the total patient outcome should be an objective of further research. This project was supported from educational grant of Pfizer Inc.