Evaluation of the correlation between scales determining disease severity in patients with moderate‐severe chronic plaque‐type psoriasis

Background Psoriasis is a chronic erythematous‐squamous disease. The results of studies related with the correlation between methods used in determining disease severity are contradictory. Aims The aim of this cross‐sectional study is to evaluate the correlation between Psoriasis Area and Severity Index (PASI) and body surface area (BSA) involvement which are used to determine psoriasis severity and which are evaluated by the physician and Dermatology Life Quality Index (DLQI) and Psoriasis Disability Index (PDI) which are evaluated by the patients. Methods Demographic data, PASI, BSA, DLQI, and PDI values of the patients were recorded. The correlation between the scales was evaluated. Results 51 patients, 11 female (21.6%) and 40 male (78.4%), were included in the study. Average age was found as 44.76 ± 11.14, while average disease duration was found as 20.74 ± 7.94. Average PASI, BSA, DLQI and PDI values were found as 17.27 ± 7.49, 33.90 ± 13.87, 15.09 ± 7.48, 23.58 ± 10.20, respectively. In the evaluation of the correlation between the scales, while PASI was found to be correlated with BSA involvement (r = 0.780 P  = .000), DLQI and PDI were not found to be correlated. On the other hand, correlation was also found between DLQI and PDI (r = 0.641 P  = .000). Conclusion There is no correlation between physical assessment methods (PASI, BSA) and quality of life scales (DLQI, PDI).