Polarized Versus Diffractive Microscopy in Distinguishing Scarring From Non-Scarring Alopecia

This study evaluated the effectiveness of polarized light microscopy versus diffractive microscopy in diagnosing alopecia using 152 scalp biopsy slides. Polarized light microscopy demonstrated superior performance in distinguishing between scarring and non-scarring alopecia, with a high specificity of 94.9% and an AUC of 0.804, compared to diffractive microscopy, which had an AUC of 0.585. The intensity of polarization provided clearer separation between the two types of alopecia, making it a valuable tool in histologic diagnosis. Additionally, a circumferential perifollicular halo was more frequently observed in non-scarring alopecia, particularly in androgenetic alopecia.