34863 Clinical clues to differentiate dermatophytoma onychomycosis and dermatophytoma-like traumatic onychodystrophy

Abstract

Background: Dermatophytoma onychomycosis (DP-OM) which was resistant form of onychomycosis presented as white or yellow wedged shape nail involvement. However, traumatic onychodystrophy could be presented as dermatophytoma-like form (DP-TO). This study aimed to discriminate factors between DP-OM and DP-TO. Methods: This is a retrospective chart review of patients who presented with white or yellow wedged shape nail involvement and visited dermatologic outpatient clinic during January 2010 to July 2020. Positive direct microscopy or fungal culture or histology were required to diagnose DP-OM. Results: A total of 36 nails were included in the study. Eighteen nails (50.0 %) had positive fungal laboratory result and were classified as DP-OM. While the remains with negative all laboratory result were diagnosed as DP-TO. Demographic data and predisposing factors for onychomycosis was not statistically different between 2 groups. Regarding physical examination, longitudinal striae and spike jagged proximal edge were found more common in the DP-OM group than in DP-TO group without statistical significance. However, 10 (55.6%) DP-TO cases had linear edged distal onycholysis which was not found in DP-OM cases (P < .001). Plantar scales which suspected fungal feet infection were significantly found higher in DP-OM than DP-TO (P = .003). Conclusion: Linear edged distal onycholysis and plantar scale were the important clues to differentiate DP-OM from DP-TO.