Diagnostic Efficacy of Electrical Impedance Spectroscopy Versus Dermoscopy for Pigmented Skin Lesions: A Pilot Study

Introduction: Electrical impedance spectroscopy (EIS) is a non-invasive diagnostic device that measures the electrical impedance of skin lesions to assist in the detection of melanoma. While this tool has been shown to have a high sensitivity for melanoma diagnosis, data on its impact on clinical decision-making for pigmented skin lesions (PSLs) compared to other diagnostic tools is lacking. To gain further insight into its clinical utility, we conducted a pilot study to evaluate how this technology – specifically, the effect it has on clinical decisions for PSLs – compares to traditional dermoscopy. Methods: Dermatologists, dermatology residents, and medical students completed an online survey eliciting their biopsy decisions for 24 PSLs of varying histopathological diagnoses. Half of the lesions from each diagnosis group were presented as a clinical image with associated dermoscopic image and the other half as a clinical image with the corresponding EIS score. Results: Decisions made with EIS demonstrated a mean sensitivity of 75% for melanomas/severely dysplastic nevi vs. 66% for decisions made with dermoscopy (p=.008). While dermatologists biopsied with similar sensitivities when using EIS or dermoscopy (81% vs. 81%), residents and medical students biopsied with significantly greater sensitivity when using EIS. Respondents who reported rarely using dermoscopy showed the greatest improvement in sensitivity and specificity when using EIS compared to dermoscopy. Conclusion: Given that not all providers are trained in dermoscopy, and our finding that EIS particularly benefits those who infrequently use dermoscopy, EIS may complement dermoscopy by helping a broader range of providers make improved PSL diagnostic decisions.