PASI scores were significantly correlated with sleep quality, duration, and disturbances.
Patients with psoriasis who experience pruritis and resulting sleep impairments demonstrated a lower quality of life in all domains, according to a cross-sectional correlation study published in Scientific Reports.1
Investigators Zaky et al note that the literature has robustly described correlations between pruritic itch and sleep disturbances in patients with psoriasis, leading to further correlations with their overall quality of life. While the intensity of pruritus is often lower in severity than in patients with other dermatologic conditions such as atopic dermatitis and chronic urticaria, study authors note, itch associated with psoriasis often intensifies in the evening.
The study involved 177 patients with psoriasis who had received a clinical diagnosis and who had been recruited from outpatient facilities. All patients had been living with a diagnosis of psoriasis for at least 6 months prior to study inclusion. Patients with concomitant conditions that may influence or cause pruritus, including cholestasis, chronic uremia, pustular psoriasis, or psoriatic arthritis, were excluded from participation, as were any patients who were presently pregnant, lactating, or had existing psychiatric conditions.
Patients completed a questionnaire inquiring about basic demographic information, history of coexistent chronic diseases, current prescription drug use, and duration of disease.
Additionally, all patients completed a dermatological examination to rule out other concomitant dermatologic conditions and to grade disease severity and implications using the Psoriasis Area and Severity Index (PASI), Psoriasis Disability Index (PDI), Pittsburgh sleep quality index (PSQI), and a 12-item pruritus severity scale (PSS).
Of all patients involved in the study, 4% had severe PASI scores, while 20% were moderate, and 76% were mild. However, 34% of patients presented with severe pruritus, 32% with moderate pruritus, and 34% with mild pruritus.
The median PDI score among all patients was a 5 (range: 0 to 26). Approximately 16% of patients reported experiencing poor sleep quality.
As a result, investigators were able to determine a statistically significant correlation between sleep efficiency and type of psoriasis, with scores of 0 detected in 83.3% of those with scalp psoriasis, 78.2% with plaque psoriasis, and 56.2% with palmoplantar psoriasis. Of all 3 psoriasis types, those with plaque psoriasis experienced significantly lower sleep efficiency.
Poor sleep also correlated with disease severity, with poor sleep detected in 50% of patients with severe psoriasis, 25% with moderate psoriasis, and 11.8% with mild psoriasis. Duration also positively correlated with sleep quality.
Both PSS and PDI scores were significant predictors of global sleep scores and poor sleep quality. Furthermore, patients with psoriatic arthritis more-frequently experienced sleep disturbances (45.1%) versus patients with psoriasis (16%).
Potential study limitations included its cross-sectional design, an absence of a control group without psoriatic disease, and an uneven distribution of skin lesion severity, according to investigators.
"The current study confirmed previous reports demonstrating that psoriasis severity is associated with increased risk of having sleep disturbances," study authors wrote. "Psoriatic patients with pruritus and sleep problems had a worse overall quality of life in all domains. Sleep impairment and screening of any depressive and impaired quality of life symptoms shall be considered when treating psoriatic patients."