Twenty-Nail Dystrophy: Clinical Presentations and Management

Primary Associated Conditions

The American Academy of Dermatology recommends that psoriasis is one of the most common underlying causes of twenty-nail dystrophy, producing characteristic nail changes including roughening, pitting, and longitudinal ridging 1
Nail psoriasis can present with vertical ridging and thinning of the nail plate, often accompanied by subungual hyperkeratosis, with a strength of evidence based on clinical guidelines from dermatology societies 1
When psoriasis affects fewer than 3 nails, intralesional triamcinolone acetonide 5-10 mg/cc is recommended for nail matrix involvement, with topical steroids with or without vitamin D analogs for nail bed involvement, as suggested by dermatology treatment guidelines 1
Lichen planus produces thinning of the nail plate with subungual hyperkeratosis and longitudinal ridging, which can progress to twenty-nail dystrophy, according to the British Association of Dermatologists 1, 2

Toenails require approximately 12 months and fingernails 6 months to grow out completely, as reported by the British Journal of Dermatology, indicating the need for prolonged treatment and follow-up 3