What are the treatment options for a patient with psoriasis?

Psoriasis: Essential Knowledge for Clinical Practice

Understanding Disease Severity and Treatment Selection

Treatment for psoriasis is determined primarily by body surface area (BSA) involvement: mild disease (<5% BSA) requires topical therapy, while moderate-to-severe disease (≥5% BSA) necessitates phototherapy or systemic agents. 1, 2

Disease Classification

• Mild psoriasis affects <5% BSA and typically does not involve vulnerable areas (face, genitals, hands, feet) 3
• Moderate-to-severe psoriasis involves ≥5% BSA or affects vulnerable areas regardless of total BSA 1, 2
• Quality of life impact supersedes BSA measurements: patients with symptomatic disease (pain, bleeding, itching) warrant systemic therapy even with limited BSA involvement 1

Treatment Algorithm for Mild Psoriasis (<5% BSA)

First-Line Topical Therapy

Initiate treatment with high-potency topical corticosteroids combined with vitamin D analogs (calcipotriene), which achieves 58-92% clearance rates. 1, 4

• Apply clobetasol propionate 0.05% or betamethasone dipropionate 0.05% twice daily for maximum 2-4 weeks 1, 4
• Combine with calcipotriene for synergistic effect and reduced irritation 3, 1
• Fixed-combination products (calcipotriene/betamethasone dipropionate) simplify regimens and improve compliance 1, 5

Location-Specific Modifications

• Face, genitals, intertriginous areas: Use low-potency corticosteroids or topical calcineurin inhibitors (tacrolimus, pimecrolimus) to avoid skin atrophy 1, 4, 6
• Scalp psoriasis: Apply calcipotriene foam or calcipotriene plus betamethasone dipropionate gel for 4-12 weeks 1
• Thick plaques: Use ultra-high potency (class 1) corticosteroids with salicylic acid to enhance penetration 1, 6

Critical Safety Monitoring for Topical Corticosteroids

• No unsupervised repeat prescriptions should be issued 1
• Maximum 100g of moderately potent preparation per month 1
• Regular clinical review required to monitor for skin atrophy, striae, and telangiectasia 1
• Long-term use of potent topical corticosteroids causes irreversible skin damage 1

Treatment Algorithm for Moderate-to-Severe Psoriasis (≥5% BSA)

First-Line Phototherapy

Narrowband UVB phototherapy is the first-line treatment for moderate-to-severe disease, as it is the least toxic systemic option. 1, 2

• Start at 70% of minimum phototoxic dose and increase by 40% if no erythema develops 2
• PUVA (psoralen plus UVA) is an alternative for refractory cases 1, 2
• 308-nm excimer laser targets localized resistant areas 1
• Apply vitamin D analogs after phototherapy sessions to avoid inactivation 1

When to Escalate to Systemic Therapy

Escalate to systemic agents when topical therapy plus phototherapy fails after 4-8 weeks, or when phototherapy is unavailable/contraindicated. 1, 2

Traditional Systemic Agents

• Methotrexate: Especially effective for acute generalized pustular psoriasis, psoriatic erythroderma, and psoriatic arthritis; response time 2 weeks 2
• Cyclosporine: First-line for erythrodermic psoriasis with dramatic improvement in 2-3 weeks 2
• Acitretin: Useful for palmoplantar psoriasis and pustular variants 3

Biologic Therapy

Biologics achieve treatment goals in 68.2-79.3% of patients by week 16 and should be considered when traditional systemic agents fail or are contraindicated. 2, 4

• TNF-alpha inhibitors: Adalimumab, infliximab, etanercept 3, 7
• IL-12/23 inhibitors: Ustekinumab 3
• Infliximab demonstrates rapid and often complete clearance for generalized pustular psoriasis (5 mg/kg at weeks 0,2,6, then every 8 weeks) 2, 4

Medications That Must Be Absolutely Avoided

Never Prescribe These Agents

Systemic corticosteroids are absolutely contraindicated in psoriasis—they precipitate life-threatening erythrodermic psoriasis, generalized pustular psoriasis, or severe disease flares upon discontinuation. 1, 2, 4

• Lithium, chloroquine, mepacrine: Associated with severe, potentially fatal psoriasis deterioration 2, 4
• Beta-blockers, NSAIDs, alcohol: May worsen psoriasis 1

Special Clinical Scenarios

Pregnancy

Narrowband UVB phototherapy is first-line for pregnant women with moderate-to-severe psoriasis, as it lacks systemic toxicities. 2

• All traditional systemic agents (methotrexate, acitretin, cyclosporine) are absolutely contraindicated in pregnancy 2

Palmoplantar Psoriasis

Despite affecting minimal BSA, palmoplantar psoriasis severely impacts quality of life and justifies systemic therapy when intensive topical therapy under occlusion or photochemotherapy fails 3

• Consider methotrexate, cyclosporine, or acitretin 3
• Soak PUVA (15-30 minutes in methoxsalen solution) is highly effective 3

Erythrodermic Psoriasis

• Initial management: Apply wet dressings with mid-potency topical steroids, maintain fluid balance, rule out sepsis 2
• Cyclosporine is first-line systemic therapy with dramatic improvement in 2-3 weeks 2

Combination and Rotational Strategies

• Combination therapy (topical corticosteroids plus vitamin D analogs) enhances efficacy and reduces irritation compared to monotherapy 1, 5
• Rotational therapy (switching treatment modalities every 1-2 years) minimizes cumulative toxicity 1
• Biologics can be combined with methotrexate or high-potency topical corticosteroids 2

When to Refer to Dermatology

Refer patients requiring systemic agents to a dermatologist due to potential toxicity and need for specialized monitoring. 4

• Patients with psoriatic arthritis, erythrodermic psoriasis, or generalized pustular psoriasis require specialist management 4
• Patients with >5% BSA involvement unresponsive to topical therapy after 8 weeks 1, 4

Alternative Medicine: Limited Evidence

• Fish oil/omega-3 fatty acids: May have adjunctive benefit but insufficient evidence for routine recommendation 3
• Oral vitamin D supplementation: Not recommended—topical vitamin D analogs are effective, but oral supplementation does not improve disease activity 3
• Curcumin: Limited literature suggests possible adjunctive benefit, but poor bioavailability limits efficacy 3
• Stress reduction/meditation: May have positive impact as adjunctive therapy in interested patients 3