Nail digital dermoscopy (Onychoscopy) in the diagnosis of onychomycosis

Abstract

We found distinctive dermoscopic signs that are exclusive to distal subungual onychomycosis and to traumatic onycholysis. Detection of these signs is simple and can, in selected cases, help to avoid mycology.

Dermoscopy in the Evaluation of Nail Disorders

“…In distal subungual onychomycosis, the detachment runs along the horny layer of the nail bed, which is thicker in the longitudinal furrows between the dermal creases; this explains the ragged border of the onycholysis with a jagged edge and sharp structures, directed to the proximal fold, named “spikes” [20]. …”

“…Dermoscopy shows white-yellow longitudinal striae in the onycholytic nail plate (Fig. 17), and the overall appearance of the affected nail plate with bands of fading colors resembles the aurora borealis (aurora borealis pattern) [20]. In dermatophytoma, there is a subungual accumulation of hyphae and scales that dermoscopically appears as a round-shaped yellow-orange patch in the mid nail bed, connected by a thin narrow channel to the distal edge of the nail plate (Fig.…”

Onychomycosis and Onychomatricoma

“…Dermoscopy is useful in the diagnosis of onychomycosis with two characteristic findings described at nail plate and free edge dermoscopy. Nail plate dermoscopy reveals a jagged edge appearance of the proximal margin of the onycholytic area with spikes directed to the proximal nail fold, and overall irregular pigmentation in longitudinal striae of different colors, giving an appearance similar to the aurora borealis [17] . Dermoscopy, of the frontal margin of the affected nail plate shows a 'ruin appearance' of the subungual hyperkeratosis [18] .…”

Onychomycosis in children

“…Onycholysis frequently involves the lateral side of the nail. Although nail dermoscopy may be useful for differential diagnosis, showing specific patterns for onychomycosis, mycology is mandatory to rule out fungal infection [19].…”