Psoriasis epidemiology screening tool (PEST) is useful for the detection of psoriatic arthritis in the Japanese population.

Psoriasis is a chronic inflammatory skin disease that involves various systemic organs and tissues and is characterized by scaly erythematous skin. Among the different types of psoriasis, psoriatic arthritis (PsA) is frequently reported, and occasionally develops into severe arthritis leading to joint dysfunction. There are various tools, especially questionnaires, to identify the presence of PsA in European and American populations; however, little is known about the utility of these tools in the Asian population. In this study, we investigated the utility of a representative tool, the psoriasis epidemiology screening tool (PEST) questionnaire, to identify PsA among Japanese patients with psoriasis. A total of 143 patients with psoriasis were enrolled in this study. Among them, 29 patients were diagnosed with PsA. The frequency of PsA was significantly increased in patients with PEST scores > 3, with a sensitivity of 93.1% and a specificity of 78.9%. Among the questions in the PEST questionnaire, "Have you ever had a swollen joint?" showed the highest frequency to answer "Yes" among patients with PsA. Univariate and multivariate analyses revealed that high PEST scores (> 3) was an independent variable in PsA patients. Taken together, our study suggests that the PEST questionnaire is a useful tool to identify PsA among Japanese patients with psoriasis.