Dermoscopic Patterns of Onychomycosis: A Cross-sectional Study in One Institution

Background: Several dermoscopic findings that could be helpful in diagnosing onychomycosis have been reportedin many cases, but they have not been sufficiently utilized in clinical practice.Objective: To evaluate and identify the dermoscopic findings that may assist in the accurate diagnose ofonychomycosis.Methods: The study included 42 patients with clinical features suggestive of onychomycosis based on the clinicalhistory, physical examination, dermoscopic findings, and mycological investigation. Clinical photographs and naildermoscopy images were obtained, which were retrospectively reviewed and analyzed according to the onychomycosisclassification.Results: In total, 42 representative nails were reviewed. Common dermoscopic patterns such as yellow/browndiscoloration and subungual hyperkeratosis were found in our onychomycosis patients. Key findings observed inspecific subtypes were distolateral subungual onychomycosis with "jagged edges with spikes", proximal subungualonychomycosis or white superficial onychomycosis with irregularly bordered homogeneous leukonychia withpostinflammatory hyperpigmentation on the proximal nail fold, and fungal melanonychia with nail plate roughnessand nail fold hyperkeratosis.Conclusion: Our study, along with previous studies, demonstrated dermoscopy as a quick and effective tool fordiagnosing onychomycosis. In addition, periungual dermoscopic findings can be an important clue in onychomycosisdiagnosis, especially in cases of fungal melanonychia and leukonychia.