TRACHYONYCHIA
TWENTY-NAIL
DYSTROPHY
Trachyonychia (twenty-nail dystrophy) is a nail sign that can be caused by several inflammatory disorders that produce a mild disturbance of nail matrix keratinization. These include alopecia areata, psoriasis, lichen planus, and eczema. The nail is rough and opaque due to excessive longitudinal ridging. The disease occurs most commonly in children. Trachyonychia does not produce nail scarring, even in cases due to lichen planus.
TRACHYONYCHIA (TWENTY-NAIL
DYSTROPHY) AT A GLANCE
· Idiopathic but likely reflects alopecia areata, psoriasis, dermatitis, or lichen planus of the nail. More common in children.
· Characterized by nail roughness due to excessive longitudinal ridging (sandpaper nails).
· Several nails are involved in most cases; involvement of 20 nails is not necessary for diagnosis.
· Nail changes often regress spontaneously.
· Treatment is not required.