Treatment for Psoriasis

For mild psoriasis (<5% body surface area), start with calcipotriene/betamethasone dipropionate combination product once daily for 4-8 weeks, which achieves clear or almost clear skin in 48-74% of patients. 1, 2, 3

Mild psoriasis is defined as:

Moderate-to-severe psoriasis requires systemic therapy if:

First-line treatment:

Calcipotriene/betamethasone dipropionate combination product once daily for 4-8 weeks 1, 2, 3
For trunk/extremities with thick chronic plaques: ultrahigh-potency corticosteroids (clobetasol propionate 0.05% or halobetasol propionate 0.05%) 1, 2
Maximum continuous use of high-potency corticosteroids: 4 weeks only 2

Maintenance therapy after initial control:

Transition to weekend-only high-potency corticosteroid application (twice daily on weekends) 2
Apply vitamin D analogue twice daily on weekdays 2
Maximum vitamin D analogue use: 100g per week to avoid hypercalcemia 2

Site-specific modifications:

Face/intertriginous areas: Low-potency corticosteroids or tacrolimus to avoid skin atrophy 1, 2
Scalp: Calcipotriene foam or calcipotriene plus betamethasone dipropionate gel for 4-12 weeks 1, 2
Nails: Calcipotriene combined with betamethasone dipropionate, though efficacy is limited due to poor nail matrix penetration 2

First-line options:

Narrowband UVB phototherapy for patients with ≥5% BSA or inadequate response to topicals 3
Biologic agents are now considered first-line due to superior efficacy and acceptable safety profiles 3
- IL-17 inhibitors, IL-23 inhibitors, and IL-12/23 inhibitors show higher efficacy than TNF inhibitors in head-to-head studies 3
- TNF inhibitors (e.g., adalimumab 40 mg every other week subcutaneously) are effective for both skin and joint symptoms, particularly in psoriatic arthritis 1, 4

Traditional systemic agents (second-line):

Cyclosporine 3-5 mg/kg/day: Rapid onset of action, particularly effective for erythrodermic psoriasis requiring urgent response 2
- Use in short 3-4 month "interventional" courses 2
Methotrexate: FDA-approved since 1972, but has limited efficacy as monotherapy for plaque psoriasis 2, 3
- More appropriate for patients with concurrent psoriatic arthritis 3
Acitretin: Decreases keratinocyte hyperproliferation but cannot be used in women of childbearing potential due to teratogenicity 2, 3

Adding topical therapy to systemic agents enhances efficacy:

Ultrahigh-potency corticosteroid + etanercept for 12 weeks (Level I evidence) 2
Calcipotriene/betamethasone + adalimumab for 16 weeks accelerates clearance 2
Calcipotriene + methotrexate (Level I evidence) 2
All topical corticosteroids can be combined with any biologic 2

Synergistic topical combinations:

Tazarotene 0.1% gel once daily + medium/high-potency corticosteroid for 8-16 weeks increases efficacy while reducing local adverse events 2

Never combine salicylic acid with calcipotriene simultaneously—the acidic pH inactivates calcipotriene completely 2
Avoid systemic corticosteroids in psoriasis—they cause disease flare during taper 1
Do not use high-potency corticosteroids on face or flexures—use low-potency agents or tacrolimus instead 2
Limit continuous high-potency corticosteroid use beyond 4 weeks—risk of skin atrophy, striae, telangiectasia, and HPA axis suppression 1, 2
Apply vitamin D analogues after phototherapy, not before—to avoid inactivation 1
Long-term use of high-potency corticosteroids beyond 12 weeks requires careful physician supervision 2

Psoriatic arthritis:

TNF inhibitors (adalimumab, infliximab, but not etanercept) are effective for both skin and joint symptoms 1, 4
NSAIDs for mild joint symptoms; DMARDs for moderate-to-severe joint involvement 1

Concurrent inflammatory bowel disease:

TNF inhibitors (excluding etanercept) and IL-12/23 inhibitors have demonstrated efficacy 3
Methotrexate shows efficacy in Crohn's disease and ulcerative colitis 3

Erythrodermic psoriasis:

Oral cyclosporine 3-5 mg/kg/day is the logical choice for systemically ill patients due to rapid onset 2
Base therapy on short-term efficacy, then transition to maintenance therapy after acute illness improves 2