The Impact of Sleep Dysfunction on Inflammatory Skin Diseases: A Systematic Review.

Sleep disturbance is increasingly recognized as a major comorbidity in chronic inflammatory skin diseases, driven by altered sleep architecture, circadian disruption, and pruritus-related nocturnal symptoms that exacerbate disease activity and reduce quality of life. This systematic review of 13 studies (N ≈ 189,000) identified the prevalence, correlates, and clinical implications of sleep disturbance across major dermatologic conditions, focusing on atopic dermatitis (AD) and psoriasis. In AD, poor sleep showed strong associations with higher Scoring Atopic Dermatitis (SCORAD) and Patient-Oriented Eczema Measure (POEM) scores and greater pruritus intensity, with itch emerging as the primary predictor of sleep disruption. In psoriasis, poor sleep was closely linked to higher Psoriasis Area and Severity Index (PASI) and Dermatology Life Quality Index (DLQI) scores and more severe pruritus, with depression mediating the impact of quality-of-life impairment on sleep. Genetic evidence further supported a causal relationship between insomnia and increased risk of AD and psoriasis. Collectively, findings reveal a bidirectional interplay in which nocturnal pruritus, emotional distress, and inflammation sustain one another, underscoring sleep disturbance as an integral component of dermatologic disease burden and highlighting the need for routine sleep assessment, targeted interventions, and longitudinal studies to determine whether improving sleep can reduce inflammatory activity and enhance patient outcomes.