Trachyonychia is a condition characterized by rough accentuated linear ridges (longitudinal striations) on the nails of the fingers and toes.[3] When the condition occurs on all the twenty nails of the fingers and toes, it is known as twenty-nail dystrophy, most evident in childhood,[4] favoring males.[2][5]
| Trachonychia | |
|---|---|
| Other names | Sandpapered nails,[1][2] Twenty nail dystrophy |
 | |
| Specialty | Dermatology  |
| Causes | Lichen planus |
Trachyonychia causes the nails to become opalescent, thin, dull, fragile, and finely longitudinally ridged, and, as a result, distally notched.[6] It can be a manifestation of lichen planus, psoriasis, alopecia areata, immunoglobulin A deficiency, atopic dermatitis, and ichthyosis vulgaris.[7]
"The longitudinal striations can occur as a normal part of the aging process",[2] and not until the nails start to thin and get a sandpaper look is the condition called trachonychia. The nails are opalescent and frequently are brittle and split at the free margin. There has been evidence of the condition as a cutaneous manifestation of lichen planus. It has also been associated with other diseases such as eczema, psoriasis, alopecia areata, and atopic dermatitis.[2] Trachonychia is often seen in vitiligo patients – suggesting that they are more susceptible to this condition.[2]