Disease Activity-Related Sleep Dysfunction in Psoriasis: Insights from a Cross-Sectional Study

Background/Objectives: Psoriasis (PsO) is a chronic immune-mediated disease associated with a substantial multidimensional burden extending beyond skin involvement. Sleep disturbance represents an important yet underexplored domain of patient-reported outcomes. This study aimed to investigate the relationship between PsO disease activity and sleep quality, focusing on specific sleep domains, and to evaluate whether disease severity independently predicts sleep latency and daytime dysfunction. Methods: We conducted a cross-sectional study including 136 consecutive patients with PsO from two Italian centers. Disease severity was assessed using the Psoriasis Area and Severity Index (PASI). Sleep quality was evaluated using the Pittsburgh Sleep Quality Index (PSQI), while quality of life was measured by the SF-36. Patients were stratified according to disease severity (PASI < 10 vs. ≥10). Associations between disease activity and sleep domains were analyzed using univariable and multivariable ordinal regression models adjusted for demographic and clinical variables. Results: The study population had predominantly low disease activity (median PASI 2). The median global PSQI score was 5, indicating overall borderline sleep impairment. Patients with PASI ≥ 10 showed significantly worse sleep latency (p = 0.01) and greater daytime dysfunction (p = 0.02), while no significant differences were observed in global PSQI scores. In multivariable analyses, PASI ≥ 10 remained independently associated with increased sleep latency (β = 0.95, 95% CI 0.08–1.82; p = 0.032) and daytime dysfunction (β = 2.52, 95% CI 1.31–3.73; p < 0.001), after adjustment for confounders. Conclusions: Higher PsO disease activity is independently associated with impairment in specific sleep domains, particularly sleep latency and daytime dysfunction, rather than global sleep quality. These findings highlight the importance of assessing domain-specific sleep disturbances and support the integration of sleep outcomes into a holistic, patient-centered approach to PsO management.