Lichen Planus of the Nails
Nail lichen planus (NLP) is a chronic autoimmune inflammatory disorder in which a T-cell-mediated cytotoxic reaction targets the basal keratinocytes of the nail unit. NLP can occur on its own (10–25% of lichen planus cases) or together with lichen planus of the skin or the oral or genital mucosa.
Unlike nail psoriasis or nail eczema, which do not cause permanent scarring, nail lichen planus is considered a dermatological nail emergency. The reason is that lichenoid inflammation directly attacks and destroys the nail matrix, leading to scarring and permanent nail loss if it is not treated promptly.
- Matrix Destruction and Pterygium Formation:
- Liquefaction degeneration of the basal cell layer of the matrix completely disrupts its ability to produce a nail plate.
- Once the matrix is destroyed, the skin of the proximal nail fold fuses directly with the nail bed.
- This advancing fusion forms a wing-shaped band of scar tissue called a pterygium (dorsal pterygium), the hallmark warning sign of permanent nail loss.
- Nail Thinning and Longitudinal Splitting (Onychorrhexis): The shrinking matrix produces a very thin, weak nail with deep longitudinal ridges that split from base to free edge, progressing to shedding or complete atrophy of the nail plate.
Nail lichen planus can destroy the nail quickly and irreversibly. Once a pterygium has fully formed, the matrix at that site is scarred and cannot grow nail again, whatever biological treatment is used. At Haute-Derma, a patient with deep longitudinal splits and thinning nails is assessed urgently: onychoscopy to spot early adhesions, a nail biopsy when needed, and immediate high-dose corticosteroids to stop the destruction of basal cells.
Clinical Features and Types
- Early changes (reversible stage):
- Nail plate thinning: The nail loses its normal thickness and becomes translucent, brittle and easily broken.
- Deep ridging and splitting (onychorrhexis, longitudinal ridging): Deep longitudinal grooves appear and the nail plate splits into two or more strips lengthwise.
- Violaceous nail fold (violaceous erythema): The proximal nail fold turns red-purple, reflecting lichen planus papules around the nail.
- Late changes (scarring, irreversible stage):
- Nail fold adhesion (dorsal pterygium): A pathognomonic sign. The proximal nail fold grows forward and fuses with the nail bed, splitting the remaining nail plate into two separate parts.
- Permanent nail loss (anonychia): The entire matrix is scarred, the nail plate disappears and is replaced by smooth, shiny scar tissue.
- Special variants (idiopathic atrophy / ulcerative NLP):
- These variants progress extremely fast, causing painful ulceration, acute matrix necrosis and anonychia of all 20 nails within weeks to months.
Telling Nail Lichen Planus, Nail Psoriasis and Nail Eczema Apart
| Nail Lichen Planus | Nail Psoriasis | Nail Eczema |
|---|---|---|
| Destruction of matrix basal cells > scarring | Hyperkeratosis and autoinflammation > no scarring | Nail fold inflammation and cuticle damage |
| Thin nail plate, deep longitudinal splits | Thickened nail, subungual hyperkeratosis | Thick, rough nails with transverse ripples (washboard) |
| Pterygium present (characteristic; warns of permanent scarring) | No pterygium | No pterygium |
| Risk of permanent nail loss | No risk of nail loss | No risk of nail loss |
| Pitting rare | Prominent pitting | Shallow pitting |
Urgent Treatment and Medical Management
The goal of treatment is to SHUT DOWN ACUTE INFLAMMATION AND PROTECT THE NAIL MATRIX before scarring sets in.
Intralesional Injection (ILI) – First Choice for Localized Disease
Started as soon as NLP is confirmed in one or a few nails:
- Drug: Triamcinolone acetonide (TAC) 2.5–5.0 mg/mL.
- Technique: Injected into the proximal nail fold, just above the matrix.
- Dose: 0.1 mL per injection site (2 sites per nail).
- Frequency: Every 3–4 weeks until the inflammation has fully settled and new nail is growing out normally.
Urgent Systemic Therapy
Used when many nails are affected, the disease is progressing quickly or a pterygium is threatening to form:
- High-dose oral corticosteroids / pulse therapy:
- Oral prednisolone 0.5–1 mg/kg/day for 4–6 weeks, then tapered over 3–6 months.
- Or intravenous pulse methylprednisolone (500 mg/day for 3 consecutive days each month).
- Systemic retinoid (acitretin):
- 0.25–0.5 mg/kg/day. Helps normalize keratinization and reduce the lichenoid infiltrate.
- Immunomodulators and JAK inhibitors:
- Cyclosporine: 3–5 mg/kg/day brings acute inflammation under control very quickly.
- Upadacitinib / tofacitinib (JAK inhibitors): These newer targeted therapies have improved refractory nail lichen planus in some reports and help stop scarring from progressing.
