What is the recommended treatment plan for psoriasis?

Treatment of Psoriasis

For mild psoriasis (<5% body surface area), start with combination calcipotriene/betamethasone dipropionate applied once daily for 4 weeks, which provides superior efficacy and fewer adverse effects than either agent alone. 1

Disease Severity Classification

Mild psoriasis is defined as:

• Less than 5% body surface area involvement 1
• Generally asymptomatic (no pain, bleeding, or itching) 1
• However, involvement of high-impact sites (face, scalp, palms/soles, nails, genitalia) constitutes severe disease regardless of body surface area due to marked quality of life impairment 2

Moderate-to-severe psoriasis requires at least one of:

• ≥5% body surface area involvement 1
• Symptomatic disease (pain, bleeding, itching) 1
• More than minimal impact on quality of life 1
• Inadequate response to topical therapy 1

First-Line Treatment for Mild Psoriasis

Combination Topical Therapy (Preferred)

The most effective topical approach is calcipotriene 0.005% plus betamethasone dipropionate 0.064% as a single combination product applied once daily for 4 weeks. 3, 1, 2

• This combination achieves 69-74% of patients reaching clear or almost clear status compared to 27% with vehicle 3, 1
• No serious adverse events including striae or hypothalamic-pituitary-adrenal axis suppression were observed over 52 weeks of treatment 3
• The combination is more effective than either agent alone and reduces adverse effects of corticosteroids 3, 1, 2

Maintenance Strategy After Initial Control

After achieving initial control at 4 weeks, transition to weekend-only corticosteroid application with weekday vitamin D analogue therapy to minimize corticosteroid exposure while maintaining efficacy. 1

• Apply high-potency topical corticosteroid twice daily on weekends only 1
• Apply vitamin D analogue twice daily on weekdays 1
• Maximum vitamin D analogue use: 100g per week to avoid hypercalcemia 1

Alternative Regimen

Morning high-potency topical corticosteroid with evening topical vitamin D analogue is an effective alternative regimen. 1, 2

Monotherapy Options (When Combination Not Available)

Topical corticosteroids:

• For trunk/extremities: Use class 2-5 (moderate to high potency) corticosteroids initially 1
• For thick, chronic plaques: Use class 1 (ultrahigh-potency) agents like clobetasol propionate 0.05% or halobetasol propionate 0.05%, which achieve clearance in 58-92% of cases 1, 2
• Maximum continuous use of high-potency corticosteroids: 4 weeks 1
• Long-term use beyond 12 weeks requires careful physician supervision 1

Vitamin D analogues:

• Can be used for up to 52 weeks 3, 1
• Calcipotriene, calcitriol, tacalcitol, and maxacalcitol are all effective 3

Site-Specific Treatment Modifications

Scalp Psoriasis

Use calcipotriene foam or calcipotriene plus betamethasone dipropionate gel for 4-12 weeks as first-line treatment. 3, 1, 4

• Vehicle formulations (solutions, foams, shampoos) improve adherence compared to creams or ointments 4
• Generic clobetasol propionate 0.05% solution applied twice daily is highly effective and among the least expensive options 2
• Class 1-7 corticosteroids can be used on the scalp for up to 4 weeks as initial and maintenance therapy 1, 4

Facial and Intertriginous Psoriasis

Use low-potency corticosteroids or calcitriol ointment to avoid skin atrophy. 1

• Tacalcitol ointment or calcipotriene combined with hydrocortisone for 8 weeks is recommended 3
• Tacrolimus is first-line for intertriginous psoriasis due to efficacy without causing atrophy 1
• Never use high-potency corticosteroids on face or flexures due to increased risk of cutaneous atrophy 1

Nail Psoriasis

Topical vitamin D analogues combined with betamethasone dipropionate reduces nail thickness, hyperkeratosis, onycholysis, and pain. 3, 1

• Note: Topical agents have limited efficacy for severe nail disease due to poor nail matrix penetration 3, 1

Critical Pitfalls to Avoid

Never combine salicylic acid with calcipotriene simultaneously—the acidic pH inactivates calcipotriene and eliminates its effectiveness. 3, 1

Do not use high-potency corticosteroids on face or flexures—use low-potency agents or tacrolimus instead. 1

Limit continuous high-potency corticosteroid use to prevent skin atrophy, striae, telangiectasia, and HPA axis suppression. 1

Apply vitamin D analogues after phototherapy to avoid inactivation by UVA radiation. 3, 4

First-Line Treatment for Moderate-to-Severe Psoriasis

For moderate-to-severe psoriasis (≥5% body surface area or symptomatic disease), biologic therapy with adalimumab or infliximab is recommended as first-line systemic treatment. 2, 5, 6

Adalimumab Dosing

• 80 mg initial dose subcutaneously 2, 5
• 40 mg at week 1 2, 5
• 40 mg every 2 weeks thereafter 2, 5
• Achieves PASI 75 in 71% of patients at week 16 compared to 7% with placebo 2

Infliximab Dosing

• 5 mg/kg IV at weeks 0,2, and 6, then every 8 weeks 2
• Achieves PASI 75 in 79-80% of patients by week 10 2
• Concomitant methotrexate is required to limit immunogenicity; without it, approximately 19% develop anti-infliximab antibodies 2

Etanercept Dosing

• 50 mg subcutaneously twice weekly for 12 weeks 2
• Then 50 mg once weekly for maintenance 2
• Achieves PASI 75 in 48-66% at week 12 2

Newer Biologics (Highest Efficacy)

The American Academy of Dermatology recommends infliximab, bimekizumab, ixekizumab, or risankizumab as first-line systemic therapy for severe plaque psoriasis because they achieve PASI 90 responses in 70-80% of patients. 2

• Bimekizumab: PASI 90 in 84% (anti-IL-17) 2
• Ixekizumab: PASI 90 in 84% (anti-IL-17) 2
• Risankizumab: PASI 90 in 80% (anti-IL-23) 2

Combination Strategies to Enhance Biologic Efficacy

Adding high-potency topical corticosteroid to etanercept for 12 weeks accelerates plaque clearance. 1, 2

Adding calcipotriene/betamethasone dipropionate to adalimumab for 16 weeks accelerates clearance. 1, 2

Adding topical calcipotriene to methotrexate improves outcomes. 1, 2

All topical corticosteroids can be combined with any biologic. 1

Traditional Systemic Therapies

Cyclosporine

For rapid onset in severe, recalcitrant, or erythrodermic psoriasis requiring rapid response, use cyclosporine 3-5 mg/kg/day in short 3-4 month courses. 1, 2

• At 5 mg/kg/day, 65% achieve clear/almost clear status after 8 weeks 2
• Monitor blood pressure and serum creatinine every 2 weeks for 3 months, then monthly 2
• Monitor monthly CBC, liver enzymes, lipids, electrolytes 2
• Contraindicated with impaired renal function, uncontrolled hypertension, active malignancy 2

Methotrexate

Methotrexate is effective for severe, recalcitrant, disabling psoriasis not responsive to other therapies. 1, 6, 7

• Contraindicated with significant alcohol intake or liver disease 1
• Associated with lower incidence of serious adverse events compared to most biologics 2

Acitretin

Acitretin decreases keratinocyte hyperproliferation and restores normal epidermal differentiation, but cannot be used in women of childbearing potential due to teratogenicity. 1

• PASI 75 achieved in 23% at 8 weeks with 50 mg/day 2
• PASI 50 achieved in 75% at 6 months and 88% at 12 months 2
• Particularly suitable for postmenopausal women 1

Special Considerations for Psoriatic Arthritis

For patients with psoriatic arthritis of any severity, adalimumab is recommended as monotherapy because it treats both skin and joint symptoms and inhibits radiographic joint damage. 2, 5

Infliximab also inhibits radiographically detected joint damage in psoriatic arthritis. 2

Safety Monitoring for Biologics

Perform tuberculosis screening (PPD skin test or interferon-γ release assay) before initiating any biologic; treat latent TB before starting therapy. 2, 5

Ongoing monitoring for active TB is required throughout biologic treatment, even after a negative baseline test. 2

Discontinue biologic if a patient develops a serious infection or sepsis during treatment. 5

Management of Treatment Failure

Failure to respond to one TNF-α inhibitor does not preclude successful response to a different TNF-α inhibitor, although overall efficacy may be reduced. 2

Failure of any biologic does not preclude successful response to ustekinumab. 2

When retreating after a drug holiday of >3-4 half-lives or during a flare, repeat loading doses are advised. 2