What is the best treatment approach for a patient with nail plate and nail bed psoriasis?

Treatment of Nail Plate and Nail Bed Psoriasis

Severity-Based Treatment Algorithm

For patients with nail plate and nail bed psoriasis, treatment selection depends primarily on the number of affected nails and anatomical involvement: use intralesional triamcinolone acetonide 5-10 mg/cc for isolated nail matrix disease affecting fewer than 3 nails, topical corticosteroids combined with vitamin D analogues for nail bed involvement, and biologic DMARDs (particularly IL-17 or IL-12/23 inhibitors) for moderate-to-severe disease involving more than 3 nails or when concurrent psoriatic arthritis is present. 1, 2

Limited Disease (≤3 Nails Affected)

For nail matrix involvement specifically:

• Intralesional triamcinolone acetonide 5-10 mg/cc is the primary treatment, as it directly targets the source of nail plate abnormalities including pitting, leukonychia, and crumbling 1, 2
• This approach is more effective for matrix disease than topical treatments due to direct delivery to the affected tissue 1

For nail bed involvement specifically:

• High-potency topical corticosteroids (such as clobetasol 0.05% cream) applied under occlusion are first-line therapy 1
• Combine with topical vitamin D analogues (calcipotriene/betamethasone dipropionate) once daily to reduce onycholysis, subungual hyperkeratosis, and pain 1
• Critical pitfall to avoid: Never combine salicylic acid with calcipotriene simultaneously, as the acidic pH inactivates calcipotriene and eliminates its effectiveness 1, 3

For combined matrix and bed involvement:

• Use concurrent intralesional triamcinolone acetonide for matrix disease plus topical corticosteroids with vitamin D analogues for bed disease 2
• Topical tazarotene 0.1% cream under occlusion can be added for enhanced efficacy, but is contraindicated in pregnancy and requires effective contraception in females of reproductive potential 1

Moderate-to-Severe Disease (>3 Nails Affected)

Systemic therapy becomes necessary when more than 3 nails are affected or when topical treatments have failed. 1

First-line systemic options:

• Biologic DMARDs are strongly recommended as the most effective treatment for moderate-to-severe nail psoriasis, particularly TNF inhibitors (adalimumab, etanercept, infliximab, golimumab), IL-17 inhibitors (secukinumab, ixekizumab), IL-12/23 inhibitors (ustekinumab), and IL-23 inhibitors (guselkumab, risankizumab). 1, 2
• IL-17 inhibitors may have superior short-term efficacy compared to IL-23 and TNF-alpha inhibitors, though long-term efficacy is similar to TNF-alpha inhibitors 4
• Adalimumab demonstrated 47% mNAPSI 75 response at 26 weeks in nail psoriasis trials, with 49% achieving PGA-F clear or minimal with ≥2-grade improvement 5

Second-line systemic options when biologics are not appropriate:

• Acitretin 0.2-0.4 mg/kg/day for patients with more than 3 affected nails 1
• Methotrexate 15 mg/week, particularly when significant skin involvement is present 1
• Cyclosporine may be effective but should be limited to less than 12 consecutive months due to cumulative nephrotoxicity 1
• Apremilast is a second-line option for patients with nail psoriasis 1

Special Considerations for Concurrent Psoriatic Arthritis

When psoriatic arthritis is present (which occurs in up to 90% of patients with nail changes), biologic DMARDs should be first-line therapy regardless of the number of nails affected. 2, 6

• Nail psoriasis is considered a vulnerable area that may warrant systemic therapy even with limited body surface area involvement, due to the high risk of progressive psoriatic arthritis 1
• Recommended biologics include adalimumab, etanercept, infliximab, golimumab, secukinumab, ixekizumab, ustekinumab, guselkumab, and risankizumab 1

Critical Clinical Pitfalls

Always evaluate for onychomycosis before initiating treatment, as secondary candidal infection occurs commonly in psoriatic nails and requires fungal culture to guide appropriate antimicrobial therapy. 2, 6

Never use systemic corticosteroid monotherapy for psoriasis, as skin disease can flare during or after taper, potentially triggering pustular or erythrodermic forms. 1

Recognize that topical treatments have significant limitations in treating severe nail disease due to poor penetration of the nail plate. 1

Monitoring and Expectations

• Clinical improvement with topical treatments may not be synonymous with mycological cure when fungal superinfection is present 7
• Nail psoriasis has an unpredictable course but is typically chronic, with complete remissions being uncommon 8
• Sun exposure does not usually improve and may even worsen nail psoriasis 8
• Treatment duration for topical therapy typically ranges from 6-12 months, while biologic therapy shows response within 12-26 weeks 1, 5