Nail Signs due to abnormal nail matrix function – sandpapered nails 粗面甲

Trachyonychia (sandpapered nails) presents as a rough surface affecting all of the nail plate and up to 20 nails (20 nails dystrophy). The affected nails are opaque, lusterless and rough; the nail plate surface has longitudinal ridging due to fine superficial striations distributed in a regular, parallel sandpapered patten. Conditions that may cause trachyonychia include alopecia areata (common), lichen planus (uncommon), psoriasis (rare), and eczema (very rare). There is some response to potent topical, locally injected and systemic steroids, but this may be temporary.




  1. N Zaias: The Nail in Health and Diseases. 2nd ed 1990 Appleton & Lange Connecticut
  2. KA Gordon, JM Vega, A Tosti: Trachyonychia: a comprehensive review. Indian J Dermatol Venereol Leprol. 77:640-645 2011
  3. David AR Berker, Bertrand Richart, Robert Baran In: Christopher Griffiths, Jonathan Barker, Tanya Bleiker, Robert Chalmers & Daniel Creamer, editors. Rook’s Textbook of Dermatology, 9th edition. Wiley Blackwell; 2016. p95.11