What are the treatment options for a patient with psoriasis?

Treatment Options for Psoriasis

Mild Psoriasis (≤5% Body Surface Area)

Initiate treatment with high-potency topical corticosteroids combined with calcipotriene (vitamin D analog), which achieves 58-92% clearance rates. 1, 2, 3

Topical Corticosteroid Regimens by Body Location

Body plaques:

• Apply clobetasol propionate 0.05% or betamethasone dipropionate 0.05% twice daily for maximum 2-4 weeks 1, 2, 3
• Combine with calcipotriene for synergistic effect 1
• Fixed-combination products (calcipotriene/betamethasone dipropionate gel or foam) provide convenient once-daily application for 4-12 weeks 3

Scalp involvement:

• Use clobetasol propionate 0.05% shampoo twice weekly, providing rapid symptom relief within 3-4 weeks 3

Face, genitals, intertriginous areas:

• Apply low-potency corticosteroids or topical calcineurin inhibitors to minimize atrophy risk 2, 3

Alternative topical options when first-line fails:

• Start with 0.5-1.0% crude coal tar in petroleum jelly, increasing concentration every few days to maximum 10% 2
• Dithranol (Anthralin) can be started at 0.1-0.25% concentration and increased in doubling concentrations as tolerated, using short contact mode (15-45 minutes every 24 hours) 2

Critical Safety Requirements for Topical Therapy

• Implement mandatory clinical review every 4 weeks during active treatment with no unsupervised repeat prescriptions for high-potency agents 3
• Limit moderate-potency corticosteroid use to maximum 100g per month 2, 3
• Require dermatological supervision for class 1-2 preparations 3

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Moderate-to-Severe Psoriasis (>5% Body Surface Area)

Escalate to systemic therapy when body surface area involvement exceeds 5%, when there is inadequate response to optimized topical therapy after 8 weeks, or when signs of erythrodermic or pustular psoriasis develop. 2, 3

First-Line Systemic Treatment: Photochemotherapy (PUVA)

PUVA is the least toxic systemic agent and should be considered first-line systemic treatment. 4, 1, 2, 3

• Starting dose: 70% of minimum phototoxic dose (read at 72 hours) 4, 2, 3
• Increase successive doses by 40% of the immediately preceding dose if there is no erythema 4, 2, 3
• Response time: 4 weeks 4
• Requires ultraviolet A eye protection and shielding of genitalia unless specific need to treat 4, 1

Contraindications for PUVA: 4

• Pregnancy or wish to conceive
• Clinically significant cataracts
• Age <18 years
• Previous cutaneous malignancy
• Previously received ionizing radiation

Conventional Systemic Agents

Methotrexate:

• Especially useful in acute generalized pustular psoriasis, psoriatic erythroderma, psoriatic arthritis, and extensive chronic plaque psoriasis in elderly or infirm patients 4, 1
• Response time: 2 weeks 4, 2, 3
• Dose should not exceed 0.2 mg/kg body weight 4
• Absolute contraindications: pregnancy, breastfeeding, wish to father children, significant hepatic damage, anemia, leucopenia, thrombocytopenia 4, 2, 3

Cyclosporin:

• First-line for erythrodermic psoriasis, with dramatic improvement during 2-3 weeks 1
• Response time: 3 weeks 4, 3
• Contraindications: abnormal renal function, uncontrolled hypertension, previous or concomitant malignancy 4, 3
• Requires blood pressure and serum creatinine monitoring 4

Acitretin (Etretinate):

• Response time: 6 weeks 4, 2, 3
• Absolute contraindication: pregnancy or wish to conceive within 2 years of stopping treatment 4, 3
• Requires contraception, liver function tests, and fasting serum lipids monitoring 4

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Biologic Therapy

Biologics (adalimumab, infliximab, ustekinumab, etanercept) achieve treatment goals in 68.2-79.3% of patients by week 16. 1, 2

For generalized pustular psoriasis, infliximab demonstrates rapid and often complete disease clearance and should be considered first-line biologic therapy. 1, 2, 3

• Standard dosing: 5 mg/kg infused at weeks 0,2, and 6, then every 8 weeks thereafter 2, 3

Adalimumab dosing for plaque psoriasis: 5

• 80 mg initial dose, followed by 40 mg every other week starting one week after initial dose

Important safety considerations for biologics: 5

• Screen for active or latent tuberculosis, hepatitis B, and fungal infections
• Increased risk of serious infections leading to hospitalization or death
• Lymphoma and other malignancies have been reported

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Critical Medications to ABSOLUTELY AVOID

Never prescribe systemic corticosteroids for psoriasis, as they precipitate erythrodermic psoriasis, generalized pustular psoriasis, or very unstable disease upon discontinuation. 1, 2, 3

Other medications that cause severe, potentially fatal psoriasis deterioration: 1, 2, 3

• Lithium
• Chloroquine
• Mepacrine

Additional medications that may worsen psoriasis: 3

• Beta-blockers
• NSAIDs
• Alcohol

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Special Considerations for Erythrodermic Psoriasis

Initial management: 1

• Apply appropriate wet dressings with mid-potency topical steroids
• Maintain attention to fluid balance
• Rule out sepsis with blood cultures

First-line systemic options: 1

• Acitretin
• Biologic agents
• Cyclosporine
• Methotrexate

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Common Pitfalls to Avoid

Perceived "tachyphylaxis" to topical corticosteroids is often due to poor patient adherence rather than true receptor down-regulation. 2

• Address compliance issues before switching therapies
• Implement periods each year when alternative treatments are employed 2

Salicylic acid inactivates calcipotriene: 3

• Avoid combining salicylic acid with calcipotriene, as acidic pH reduces effectiveness

Combination treatment toxicity: 4

• Toxicity from any combination treatment is at least additive
• Exercise extreme caution before instigating combination treatment
• Careful monitoring is essential