Role of Dermoscopy in the Diagnosis of Hypertrophic Lichen Planus and Prurigo Nodularis

Background: A dermoscope is an office tool used in the diagnosis of various disorders. At present, studies on hypertrophic lichen planus (HLP) and prurigo nodularis (PN) are limited. Aims and Objectives: The aim of this study was to compare the dermoscopic features of HLP and PN and to determine the role of dermoscopy in the differential diagnosis of both the conditions. Materials and Methods: A cross-sectional study was undertaken. After clinical assessment and relevant investigations, dermoscopy was performed using DermLite DL3 dermoscope (x10) followed by histopathology. Dermoscopic findings in cases of HLP and PN were evaluated. Results: Thirty patients each with HLP and PN were included in the study. On dermoscopy, peripheral striations were the most common findings in both the conditions. Statistically significant features on intergroup comparison included blue-gray globules (P<0.001), comedo-like openings (P<0.001), and follicular plugging (P<0.001) in HLP and pearly white areas with white starburst pattern (P=0.028), red dots and globules (P<0.001), glomerular vessels (P=0.003), crusting (P=0.002), and erosions (P<0.001) in PN. Conclusion: Dermoscopy is useful in differentiating HLP and PN. Blue-gray globules, comedo-like openings, and follicular plugging were specific for HLP. Pearly white areas with white starburst pattern and red dots and globules were the specific findings in PN.