Onychotillomania
From dermoscopedia
In Fitzpatrick’s type IIIb, IV and V patients, postinflammatory and particularly posttraumatic pigmentation of the skin is not uncommon. This phenomenon also occurs on the nails. An excellent example of this occurs in cases of symmetrical pigmentation of the fifth toenail in women due to tight-fitting shoes. Self-provoked repetitive trauma of the nail in onychotillomania may also cause longitudinal pigmentation. Dermoscopic diagnosis is based on the observation of a gray pigmentation of the band. In a few cases, the pigmentation can vanish after suppression of the causative repetitive trauma.
