Clinical utility of peripheral blood laboratory testing in the diagnostic workup of prurigo nodularis: A multicenter cohort study

JAAD Int. 2023 Aug 12:13:74-82. doi: 10.1016/j.jdin.2023.07.015. eCollection 2023 Dec.

Abstract

Background: Prurigo nodularis (PN) is a chronic inflammatory skin disease associated with several systemic comorbidities. However, there is lack of evidence supporting specific laboratory testing in the diagnostic workup of PN patients.

Objective: To characterize the frequency and severity of clinical laboratory abnormalities in PN patients compared to controls.

Methods: Cross-sectional study of adult patients between October, 2015 and August, 2021 using TriNetX, a global health records database encompassing over 74 million patients.

Results: A total of 12,157 PN patients were matched to 12,157 controls. Significantly, greater proportions of PN patients had moderate-to-severely decreased hemoglobin, elevated transaminases, decreased albumin, increased bilirubin, increased serum creatinine, decreased estimated glomerular filtration rate, higher hemoglobin A1c levels, and alterations in thyroid stimulating hormone.

Limitations: Our data identifies associated laboratory abnormalities in PN patients but is unable to support a causal relationship.

Conclusion: PN patients are more likely to have laboratory abnormalities on renal, hepatic, hematologic, endocrine, and metabolic laboratory testing, demonstrating a role for systemic testing in the diagnostic workup of PN patients.

Keywords: diagnostic; itch; prurigo nodularis; pruritus; systemic; workup.