What are the treatment options for psoriasis?

Treatment Options for Psoriasis

For psoriasis treatment, a stepwise approach based on disease severity is recommended, with topical therapies for mild disease, phototherapy for moderate disease, and systemic/biologic agents for severe disease or those with psoriatic arthritis. 1

Disease Classification and Treatment Selection

• Psoriasis severity is categorized as mild (typically <5% body surface area [BSA]) or moderate-to-severe (≥5% BSA or involvement of vulnerable areas) 1, 2
• Patients with symptomatic psoriasis (pain, bleeding, itching) should be considered for systemic or phototherapy even if BSA involvement is limited 1, 2
• Quality of life impact should be considered when selecting therapy, as psychological distress can be significant regardless of physical extent 1

Treatment Algorithm Based on Disease Severity

For Mild Psoriasis (<5% BSA)

• First-line treatment includes topical therapies such as:
  • Topical corticosteroids (e.g., clobetasol propionate 0.05%, halobetasol propionate 0.05%) 1, 2
  • Vitamin D analogs (calcipotriene, calcitriol) 1, 2
  • Combination products (corticosteroid plus vitamin D analog) for enhanced efficacy 1, 2
  • Other options: coal tar, anthralin, and salicylic acid 1, 2

For Moderate-to-Severe Psoriasis (≥5% BSA)

• First-line: Phototherapy options such as narrowband UVB and PUVA 1
• Second-line: Traditional systemic agents:
  • Methotrexate (7.5-15 mg/week) - monitor for liver function abnormalities (15% incidence) 1, 3
  • Cyclosporine 1
  • Acitretin 1
• Third-line: Biologic agents:
  • TNF inhibitors (e.g., etanercept) - can achieve PASI 75 in 32-47% of patients after 3 months 1, 4
  • IL-17 inhibitors 1, 2
  • IL-23 inhibitors 1, 2
  • IL-12/23 inhibitors 1

Special Considerations for Specific Psoriasis Types

• For scalp psoriasis: Calcipotriene foam or calcipotriene plus betamethasone dipropionate gel for 4-12 weeks 1, 2
• For facial and intertriginous psoriasis: Low-potency corticosteroids to avoid skin atrophy 1, 2
• For nail psoriasis: Topical vitamin D analogues combined with betamethasone dipropionate, though with limited efficacy due to poor penetration 2
• For psoriatic arthritis: NSAIDs for mild joint symptoms, DMARDs for moderate-to-severe joint involvement, and TNF inhibitors (like adalimumab) for inadequate response to at least one DMARD 1

Combination and Rotational Strategies

• Combination therapy with topical corticosteroids plus vitamin D analogs enhances efficacy and reduces irritation 1, 5
• Weekday/weekend regimens (e.g., calcitriol on weekdays, clobetasol on weekends) can be effective for moderate plaque psoriasis 5
• Clobetasol propionate spray can be used as add-on therapy to biologics for additional clearing of plaques 6
• Rotational therapy (switching between treatment modalities every 1-2 years) may minimize cumulative toxicity of individual treatments 1

Common Pitfalls and Caveats

• Systemic corticosteroids should be avoided in psoriasis as they can cause disease flare during taper 1, 2
• Long-term use of potent topical corticosteroids can cause skin atrophy, striae, and telangiectasia 1
• Vitamin D analogs should be applied after phototherapy to avoid inactivation 1, 2
• Combination of multiple systemic agents may increase risk of toxicity 1
• Drugs that may precipitate or worsen psoriasis include alcohol, beta-blockers, NSAIDs, lithium, chloroquine, and mepacrine 1

Treatment Response Monitoring

• The Psoriasis Area and Severity Index (PASI) is a useful tool to assess severity and monitor treatment effectiveness 7
• For topical corticosteroids, regular clinical review is recommended with no unsupervised repeat prescriptions 1
• Among PASI 75 achievers using etanercept, the median time to PASI 50 is approximately 1 month and to PASI 75 is approximately 2 months 4
• Alternate day application of topical steroids may be as effective as once daily application in the initial 2 weeks, but by 6 weeks, once daily application shows better efficacy 8