Erythema Dyschromicum Perstans: Investigating Clinical, Demographic, and Biochemical Correlates

Abstract

Introduction

Erythema Dyschromicum Perstans (EDP) is an idiopathic, asymptomatic, chronic hypermelanotic disorder characterized by blue-gray macules that affect the face, trunk, and extremities. It disproportionately affects individuals with skin of color and remains poorly understood, with no established etiology or standardized treatment. Laboratory investigations, including complete blood counts, thyroid function tests, biochemical profiles, urinalysis, and autoantibody assays, have historically been unremarkable. EDP shares clinical features with other pigmentary disorders such as Lichen Planopilaris (LPP), making diagnosis challenging. Given the paucity of research, this study analyzes potential clinical and biochemical correlates, including age, sex, and medication use, to elucidate contributing factors and guide future management strategies.

Methods

A retrospective chart review was conducted using electronic medical records from the University of Alabama at Birmingham (UAB). Institutional Review Board (IRB) approval was obtained, and 300 patient records were accessed. Data collected included demographics, laboratory values, medication history, and histopathologic findings. All data was stored in a HIPAA-compliant database (ShareFile). Statistical evaluation identified significant associations between EDP and clinical or biochemical parameters.

Results

Our analysis assessed treatment variations among patients with ICD-10 codes L53.8 (Other specified erythematous conditions, including Erythema Dyschromicum Perstans [EDP]), L81.9 (Disorder of pigmentation, unspecified), and L81.0 (Postinflammatory hyperpigmentation [PIH]). Hydroquinone use was significantly higher in patients with L81.9 compared to those with EDP (β = 1.13050, p = 0.0161), indicating an approximately threefold increase in odds. Age was a key predictor of treatment patterns, as older patients were significantly more likely to receive hydrochlorothiazide (β = 0.03735, p = 0.0433) but less likely to receive topical treatments, including corticosteroids and calcineurin inhibitors (β = –0.10893, p = 0.000677), or topical retinoids (β = –0.03125, p = 0.0305). Additionally, dermoscopy data were available for 37 patients, with 25 having corresponding ICD-10 codes, and histopathology data were available for 26 patients, all with matching diagnoses. These data are being explored to further characterize diagnostic patterns and treatment responses. Findings emphasize the role of diagnostic classification and age in treatment selection, particularly in hydroquinone use, and highlight the need for further research on how patient demographics influence dermatologic care.

Conclusion

This study provides insight into the etiology of EDP by identifying potential clinical and biochemical correlations. By investigating demographic and laboratory data, we aim to establish patterns that contribute to EDP’s development and differentiate it from similar disorders such as lichen planus pigmentosus (LPP). Findings may facilitate improved diagnostic criteria and treatment approaches for this poorly understood condition. Integrating dermoscopy and histopathology may refine diagnosis, reduce misclassification, and promote equitable dermatologic care. Although no significant differences in Vitamin D3 levels were observed between EDP and PIH groups, further exploration of its role in pigmentary disorders may provide insight into disease mechanisms. Understanding how age and diagnostic classification influence treatment decisions may improve underrepresented patient outcomes and help optimize individualized care for pigmentary disorders.