Associations Between Factors Affecting Itching and Quality of Life in Thai Patients with Psoriasis: A Cross-Sectional Study.

Introduction: Psoriasis is a chronic skin disease affecting quality of life and causing pruritus. The factors influencing itch and its impact on the quality of life in Thai psoriasis patients are unknown. We aimed to identify these factors and their effect on quality of life.

Methods: In this questionnaire-based cross-sectional study, we included patients with psoriasis who received treatment at Chulabhorn Hospital in Thailand from January 2019 to July 2021. Interviewer is the non-dermatologist practician. The patient's information was collected, including demographic data, Itch Numeric Rating Scale (Itch NRS) score, factors affecting itch, and score on the Thai version of the Dermatology Life Quality Index (DLQI). We performed descriptive statistics and logistic regression analysis.

Results: Of 100 participants, most (99%) experienced itching, with a moderate degree of pruritus (mean Itch NRS score 6.5 ± 2.6) and a moderate effect on quality of life (mean DLQI score 9.4 ± 6.2). Factors associated with itch aggravation were dry skin (p-value = 0.003) and heat and humidity (p-value = 0.042). The results of binary logistic regression revealed that factors associated with moderate-to-extremely large DLQI scores were itch intensity (no-to-mild vs. moderate-to-severe itch: odds ratio [OR] = 13.33; 95% confidence interval [CI] = 2.72-65.32, p < 0.001; and adjusted odds ratio [AOR] = 31.17; 95% CI = 4.55-213.36; p < 0.001.

Conclusions: Our findings revealed that the quality of life among patients with psoriasis is their greatest concern. Eliminating the itch intensity that affects their quality of life is crucial but remains challenging in Thailand.