Association of onychoscopic features and clinicomycological profiles in onychomycosis - a cross-sectional study

S. Srisukhirthi, Department of Dermatology, Kanyakumari Medical Mission Research Center, Muttom, Kanyakumari, Tamil Nadu, India E. Arthi, Department of Microbiology, Pondicherry Institute of Medical Sciences, Puducherry, India Sheela Kuruvila, Department of Dermatology, Aarupadai Veedu Medical College and Hospital, Puducherry, India

Objectives: The primary objective of this study was to describe the onychoscopic patterns in patients with clinically suspected onychomycosis, and as secondary objectives, to explore the association of specific onychoscopic patterns with clinical types and the causative organisms. Methods: A cross-sectional study of 52 cases was conducted after obtaining ethical committee approval. All affected nails were subjected to clinical observation, onychoscopy, potassium hydroxide (KOH), and fungal culture. Results: We studied 34 females and 28 males, with a mean age of 47.2 ± 13years, with clinically suspected toe and fingernail onychomycosis, of whom 44 (88.5%) had a confirmatory KOH or culture, mostly with the distal lateral subungual onychomycosis subtype and caused by Candida, Fusarium, and Trichosporon. Yellow or brown chromonychia, onycholysis, distal irregular termination, rough longitudinal white edge/trachyonychia, opacity, and linear white striae were the main onychoscopic findings in this and previous studies, whereas a shallow layered appearance was a new finding. Fungal melanonychia (9.6%) and blue–red globules (3.8%) were also identified in onychoscopy. There was some correlation between onychoscopic findings and the fungus cultured from the nail plate. Conclusion: Onychoscopy can be considered a non-invasive diagnostic tool to contribute to the diagnosis of onychomycosis, as KOH examination and culture have low sensitivity. Its correlation with the causative agent could lead to a better diagnosis and facilitate the right choice of the antifungal.

Keywords: Onychomycosis. Onychoscopy. Fungal culture. Chromonychia and Onycholysis.