Onychoscopy

Pattern diagnosis of onycholysis

“…In the toenails, gait anomalies, long toenails, and inappropriate shoes are associated with traumatic linear transversal onycholysis, usually bilateral and symmetrical; the nails show a white or yellowish (due to nail thickening) colour, and on dermoscopy the proximal margin of onycholysis is sharp and linear 17–19 (Figure 5). A pathway mimicking the EKG atrial fibrillation pattern in the distal margin is another feature supporting a traumatic origin 1,20,21 …”

“…This pattern is frequently induced by mechanical trauma to the fingernails as a result of manipulation with sharp instruments under the nail, 10,20,30 such as in aggressive manicure. Other signs such as absence of cuticles, Beau's lines, lamellar onychoschyzia and paronychia may also occur 31 .…”

“…Pain and other symptoms may be present. In tumoral lateral onycholysis, the onycholytic border may be jagged or irregular and show varied colours 18,20 . Other additional features may help making the diagnosis of certain specific tumours.…”

“…A pathway mimicking the EKG atrial fibrillation pattern in the distal margin is another feature supporting a traumatic origin. 1,20,21 Linear transversal onycholysis also occurs in mechanic onycholysis as a result of leverage effect in long normal or artificial nails 15,22 (Figure 6). Nails are repeatedly pulled up with subsequent gradual detachment in the most distal point of adhesion, presenting as a flat onycholytic line.…”

“…In tumoral lateral onycholysis, the onycholytic border may be jagged or irregular and show varied colours. 18,20 Other additional features may help making the diagnosis of certain specific tumours. Remarkably, dermoscopy of the nail plate, free edge and hyponychium may easily recognise nail tumours such as onychopapilloma, onychomatricoma, fibrokeratoma, viral wart, exostosis and others 20,44 (Figure 15).…”