What are the common nail matrix and nail plate findings in patients with psoriasis and how are they managed?

Nail Matrix and Nail Plate Findings of Psoriasis

Psoriatic nail disease presents with distinct clinical findings based on anatomical involvement: nail matrix disease causes pitting, leukonychia, red spots in the lunula, and nail plate crumbling, while nail bed disease produces onycholysis, oil-drop discoloration (salmon patches), subungual hyperkeratosis, and splinter hemorrhages. 1

Clinical Manifestations by Anatomical Location

Nail Matrix Involvement

The nail matrix, when affected by psoriatic inflammation, produces characteristic changes visible on the nail plate surface:

• Pitting: Irregular, deep depressions in the nail plate representing the most common finding 2, 3, 4
• Leukonychia: White discoloration of the nail plate 2, 3
• Red spots in the lunula: Erythematous areas visible in the proximal nail 2, 3
• Nail plate crumbling: Fragmentation and destruction of the nail plate structure 2, 3

Nail Bed Involvement

Psoriatic inflammation of the nail bed manifests as:

• Onycholysis: Separation of the nail plate from the nail bed, often with an erythematous border 1, 4
• Oil-drop sign (salmon patches): Yellow-brown discoloration resembling an oil drop under the nail plate 1, 3
• Subungual hyperkeratosis: Thickening beneath the nail plate 1, 3
• Splinter hemorrhages: Linear hemorrhages under the nail plate 3, 5

Epidemiology and Clinical Significance

• Fingernails are involved in approximately 50% of all psoriasis patients and toenails in 35% 1
• Up to 90% of patients with psoriatic arthritis demonstrate nail changes, making nail involvement a critical marker for joint disease 1, 6
• Nail psoriasis can occur in all psoriasis subtypes and represents a significant therapeutic challenge 1

Management Approach

For Nail Matrix Disease (Pitting, Leukonychia)

Intralesional triamcinolone acetonide 5-10 mg/cc is the primary treatment for isolated nail matrix involvement with fewer than 3 nails affected 1

For Nail Bed Disease (Onycholysis, Oil-drop Sign)

Topical corticosteroids (mid to high potency) with or without topical vitamin D analogs are first-line for nail bed involvement 1

For Combined Matrix and Bed Involvement

Use intralesional triamcinolone acetonide AND topical steroids with or without vitamin D analogs concurrently 1

For Extensive Disease (>3 Nails)

Acitretin 0.2-0.4 mg/kg daily is recommended for patients with more than 3 nails involved 1

For Severe or Refractory Disease

When nail disease becomes dose-limiting or refractory to conventional therapy:

• IL-12/23 inhibitors (ustekinumab) or IL-17 inhibitors (secukinumab, ixekizumab) are preferred biologic options 1
• Second-line biologics include TNF inhibitors (infliximab, etanercept, adalimumab, golimumab) 1
• Apremilast may be considered as an alternative for severe disease 1

Important Clinical Pitfalls

Nail psoriasis is clinically indistinguishable from onychomycosis in many cases, particularly in toenails 3. Secondary candidal onychomycosis occurs commonly in psoriatic nails 1, necessitating fungal culture when infection is suspected to guide appropriate antimicrobial therapy.

Fingernail changes are more diagnostically visible than toenail abnormalities, where clinical features are often non-specific 3. The presence of nail psoriasis should prompt evaluation for psoriatic arthritis given the strong association, particularly when distal interphalangeal joints are involved 4.