What are the treatment options for cutaneous psoriasis?

Treatment of Cutaneous Psoriasis

For mild psoriasis (<5% body surface area), start with the fixed combination calcipotriene/betamethasone dipropionate once daily for 4-8 weeks, which achieves clear or almost clear skin in 48-74% of patients and is the most effective topical therapy available. 1

Disease Severity Classification

• Mild psoriasis is defined as <5% body surface area involvement in asymptomatic patients who are candidates for topical therapy alone 1
• Moderate-to-severe psoriasis requires systemic or phototherapy if patients have ≥5% body surface area, symptomatic disease (pain, bleeding, itching), inadequate response to topical therapy, or significant quality of life impact 1, 2
• Symptomatic psoriasis warrants systemic or phototherapy regardless of body surface area involvement 1, 2

First-Line Topical Therapy for Mild Psoriasis

Initial Treatment Strategy

• Apply calcipotriene/betamethasone dipropionate combination product once daily for 4-8 weeks as the most effective first-line topical therapy 1, 2, 3
• For trunk and extremities, high-potency corticosteroids (clobetasol propionate 0.05% or halobetasol propionate 0.05%) can be used for up to 4 weeks 4, 1
• Topical corticosteroids are strongly recommended as first-line treatment for limited body surface area involvement 4

Maintenance Therapy After Initial Control

• Transition to weekend-only high-potency corticosteroid application (twice daily on weekends) with weekday vitamin D analogue therapy (twice daily on weekdays) to minimize corticosteroid exposure while maintaining efficacy 1
• This rotational approach prevents corticosteroid-related adverse effects including skin atrophy, striae, and telangiectasia 4, 1
• Vitamin D analogues can be used safely for up to 52 weeks 1

Site-Specific Treatment Modifications

Facial and Intertriginous Psoriasis

• Use low-potency corticosteroids or calcitriol ointment for 8 weeks to avoid skin atrophy in these sensitive areas 4, 1, 2
• Topical tacrolimus is an effective alternative for intertriginous psoriasis as a steroid-sparing agent 4
• Never use high-potency corticosteroids on face or flexures due to increased risk of atrophy 1

Scalp Psoriasis

• Apply calcipotriene foam or calcipotriene plus betamethasone dipropionate gel for 4-12 weeks 1, 2
• Topical corticosteroids (class 1-7) are strongly recommended for scalp psoriasis as initial and maintenance treatment for a minimum of up to 4 weeks 4

Nail Psoriasis

• Combine calcipotriene with betamethasone dipropionate to reduce nail thickness, hyperkeratosis, and onycholysis 1
• Tazarotene 0.1% cream under occlusion for 12 weeks shows comparable efficacy to clobetasol 1
• Topical agents have limited efficacy for severe nail disease due to poor nail matrix penetration 1
• Biologic therapies (TNF inhibitors, IL-17 inhibitors, IL-12/23 inhibitors, IL-23 inhibitors) are strongly recommended for psoriatic nail disease when topicals fail 4

Combination and Sequential Strategies

• Combine tazarotene 0.1% gel once daily with medium- or high-potency corticosteroid for 8-16 weeks to increase efficacy while reducing local adverse events and prolonging remission 1
• Apply tazarotene sparingly to lesions only, avoiding perilesional skin to minimize irritation 4, 1
• Combining topical corticosteroids with vitamin D analogues is the most effective approach for mild-to-moderate psoriasis 1, 3

Treatment for Moderate-to-Severe Psoriasis

Phototherapy

• Initiate narrowband UVB phototherapy as first-line systemic treatment for patients with ≥5% body surface area or inadequate response to topicals 2
• Phototherapy is efficacious for psoriasis affecting trunk and extremities 4
• Apply vitamin D analogues after phototherapy to avoid inactivation 1

Systemic Non-Biologic Therapies

• Methotrexate inhibits dihydrofolate reductase with anti-inflammatory effects; requires monitoring of complete blood count, liver function tests, and serum creatinine 2
• Cyclosporine 3-5 mg/kg/day provides rapid onset of action, particularly effective for erythrodermic psoriasis requiring rapid response; use in short 3-4 month courses; requires monitoring of blood pressure and renal function 1, 2
• Acitretin decreases keratinocyte hyperproliferation and restores normal epidermal differentiation; has slower onset than cyclosporine; cannot be used in women of childbearing potential due to teratogenicity 1

Biologic Therapies

• TNF inhibitors, IL-17 inhibitors, IL-12/23 inhibitors, and IL-23 inhibitors are strongly recommended for widespread psoriasis or psoriasis unresponsive to topicals 4
• Newer mode of action drugs (IL-17, IL-12/23, and IL-23 inhibitors) show higher efficacy for skin involvement than TNF inhibitors 4
• Adding ultra-high potency topical corticosteroid to biologic therapy for 12 weeks enhances efficacy 2

Critical Pitfalls to Avoid

• Never combine salicylic acid with calcipotriene simultaneously—the acidic pH inactivates calcipotriene and eliminates its effectiveness 1, 2
• Avoid systemic corticosteroids in psoriasis—they cause disease flare during taper 1, 2
• Limit continuous high-potency corticosteroid use to 4 weeks maximum to prevent skin atrophy, striae, telangiectasia, and HPA axis suppression 4, 1, 2
• Do not exceed 100g per week of vitamin D analogues to avoid hypercalcemia 4, 1, 2
• Ensure regular clinical review with no unsupervised repeat prescriptions when using topical corticosteroids 4
• Include periods each year when alternative treatment is employed to minimize corticosteroid toxicity 4

Monitoring Requirements

• For topical corticosteroids: Regular clinical review to assess for skin atrophy, striae, folliculitis, telangiectasia, and purpura 4
• For methotrexate: Regular monitoring of complete blood count, liver function tests, and serum creatinine 2
• For cyclosporine: Regular monitoring of blood pressure, renal function, and lipid profile 2