Review of Nail Lichen Planus: Epidemiology, Pathogenesis, Diagnosis, and Treatment.

Nail lichen planus is an inflammatory disorder of the nails with potential for significant cosmetic disfigurement and functional impairment. Nail manifestations may be isolated or appear concurrently with other forms of lichen planus. Longitudinal ridging is the most common clinical finding, but progressive disease may result in irreversible scarring (dorsal pterygium) or permanent nail loss (anonychia). Data on treatment are limited to retrospective studies and case reports. The mainstays of treatment are intralesional and intramuscular corticosteroid injections and oral retinoids. There is a need for randomized controlled trials on nail lichen planus to more rigorously assess efficacy and outcomes.