Accuracy of dermoscopy in distinguishing erythroplasia of Queyrat from common forms of chronic balanitis: results from a multicentric observational study

Background Clinical differentiation of erythroplasia of Queyrat (EQ) and chronic forms of balanitis may be challenging, especially in early phases or in overlapping cases. Dermoscopy has been shown to be a useful supportive tool in facilitating the distinction between tumoral and inflammatory skin conditions; yet, data on EQ and balanitis are scarce or sparse. Objectives To systematically assess the dermoscopic features of both EQ and common forms of chronic balanitis and to investigate the accuracy of dermoscopy in distinguishing these conditions. Methods Subjects with EQ or chronic balanitis confirmed histologically or microbiologically (for infectious forms) were recruited. A representative dermoscopic image of a target lesion was retrospectively assessed for the presence of specific morphological findings. A correlation matrix was created using Spearman's rho. Proportions of dermoscopic variables scoring among different conditions were compared with the non-parametric Pearson's chi-square test. Results A total of 81 lesions (14 EQ, 23 psoriasis, 31 Zoon plasma cell balanitis and 13 candidal balanitis) from 81 patients were included in the study. Glomerular vessels (both clustered and diffusely distributed) were highly predictive for the diagnosis of EQ, while diffuse dotted vessels were strongly associated with psoriatic balanitis. Finally, Zoon plasma cell balanitis was characterized by orange structureless areas (focal or diffuse) and focused linear curved vessels, whereas cottage cheese-like structures (sparse white coating corresponding to Candida yeast colonies growth) showed a strong correlation with candidal balanitis. Conclusions Erythroplasia of Queyrat and balanitis may display different dermoscopic patterns, thereby bearing the usefulness of dermoscopy as a supportive non-invasive tool for the recognition and differential diagnosis of such conditions.