Median nail dystrophy (also known as "Dystrophia unguis mediana canaliformis," "Median canaliform dystrophy of Heller,"
[Freedberg, et al. (2003). ''Fitzpatrick's Dermatology in General Medicine''. (6th ed.). McGraw-Hill. .] and "Solenonychia") consists of longitudinal splitting or canal formation in the midline of the
nail
Nail or Nails may refer to:
In biology
* Nail (anatomy), toughened protective protein-keratin (known as alpha-keratin, also found in hair) at the end of an animal digit, such as fingernail
* Nail (beak), a plate of hard horny tissue at the tip ...
, a split which often resembles a
fir tree
Firs (''Abies'') are a genus of 48–56 species of evergreen coniferous trees in the family Pinaceae. They are found on mountains throughout much of North and Central America, Europe, Asia, and North Africa. The genus is most closely related to ...
, occurring at the
cuticle
A cuticle (), or cuticula, is any of a variety of tough but flexible, non-mineral outer coverings of an organism, or parts of an organism, that provide protection. Various types of "cuticle" are non- homologous, differing in their origin, structu ...
and proceeding outward as the nail grows.
[James, William; Berger, Timothy; Elston, Dirk (2005). ''Andrews' Diseases of the Skin: Clinical Dermatology''. (10th ed.). Saunders. .]
Thumbs, which are the most commonly involved, usually show an enlarged
lunula resulting probably from repeated pressure applied on the base of the nail.
See also
*
Nail (anatomy)
A nail is a claw-like plate found at the tip of the Finger, fingers and Toe, toes on most primates. Nails correspond to the claws found in other animals. Fingernails and toenails are made of a tough protective protein called alpha-keratin, which i ...
*
Habit-tic deformity
References
Conditions of the skin appendages
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