Insights into the Association Between Pruritus and Liver Disease

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Pruritus, or chronic itch, is a prevalent symptom experienced by patients with cholestatic liver diseases. However, comprehensive studies investigating its prevalence across various liver diseases remain scarce, particularly in the United States. Much of the existing literature focuses on specific conditions such as primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC), with limited insight into other liver pathologies.^1,2 Given the significant burden of pruritus on patient quality of life, researchers behind a recent study stated understanding its relationship with diverse liver diseases is essential for dermatologists and hepatologists alike.³

Study Overview

To address this gap, the study was conducted utilizing the National Institutes of Health's All of Us (AoU) Research Program, which encompasses a diverse cohort of over 400,000 adults in the US. This study aimed to assess the prevalence of chronic pruritus, defined as lasting more than 6 weeks, across various liver diseases. By employing nearest neighbor propensity-score matching, cases of chronic pruritus were compared to a control group on multiple demographic and clinical factors, ensuring robust analysis.

Findings

The study identified 22,803 cases of chronic pruritus within the AoU database, matched against 91,212 controls (mean age 61 years, 65% female). Notably, researchers found patients with chronic pruritus demonstrated a significantly higher prevalence of liver disease compared to controls. Multivariate logistic regression analysis indicated increased odds of various liver conditions among those experiencing pruritus. Notable findings included:

• Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD): Adjusted odds ratio (aOR) of 1.65 (95% CI: 1.53–1.78)
• Autoimmune Hepatitis (AIH):aOR of 1.81 (95% CI: 1.36–2.39)
• Alcohol-Related Liver Disease (ALD): aOR of 1.69 (95% CI: 1.43–1.98)
• Hepatitis B: The strongest association, with an aOR of 2.01 (95% CI: 1.67–2.42)
• Cholangitis, PSC, and PBC: aOR of 1.81 (95% CI: 1.65–1.99)

The reverse analysis also confirmed to researchers that individuals diagnosed with liver diseases had increased odds of experiencing chronic pruritus, particularly with hepatitis B (aOR 2.10, 95% CI: 1.72–2.54) and cholangitis-related conditions (aOR 1.82, 95% CI: 1.65–2.00).

Discussion and Clinical Implications

The study provides a comprehensive view of the intersection between liver disease and chronic pruritus, highlighting that this symptom is not confined to cholestatic conditions. Researchers stated the findings underscore the need for clinicians to consider liver disease as a potential underlying cause of unexplained pruritus in their patients. Notably, MASLD, which has an estimated prevalence of 38% among asymptomatic adults, warrants particular attention given its rising incidence linked to metabolic risk factors such as obesity and type 2 diabetes.

The study noted that chronic pruritus can significantly impair quality of life, affecting sleep and mental health, yet it may often go unrecognized or untreated in clinical practice. By recognizing the potential underlying liver conditions associated with pruritus, clinicians can facilitate early intervention and appropriate referrals to hepatology.

Conclusion

Overall, this study reveals a strong association between chronic pruritus and various liver diseases, extending beyond well-documented cholestatic liver conditions. Researchers wrote that it is crucial for clinicians to be aware of these associations to enhance the management of affected patients. They suggested that future research should further explore the underlying mechanisms of itch in liver disease, paving the way for targeted therapeutic strategies to alleviate the burden of chronic pruritus. The study noted that enhanced collaboration between dermatologists and hepatologists can lead to improved patient outcomes and quality of life for individuals suffering from these intertwined health issues.

References

1. Yoshikawa S, Asano T, Morino M, et al. Pruritus is common in patients with chronic liver disease and is improved by nalfurafine hydrochloride. Sci Rep. 2021;11(1):3015. February 4, 2021. doi:10.1038/s41598-021-82566-w
2. Oeda S, Takahashi H, Yoshida H, et al. Prevalence of pruritus in patients with chronic liver disease: A multicenter study. Hepatol Res. 2018;48(3):E252-E262. doi:10.1111/hepr.12978
3. Andrade LF, Haq Z, Abdi P, et al. Association of liver disease and chronicpruritus: A case-control study. Liver Int. October 18, 2024. doi:10.1111/liv.16126