What are the treatment options for a patient with psoriasis?

Treatment Options for Psoriasis

Mild Psoriasis (≤5% Body Surface Area)

Start with high-potency topical corticosteroids combined with calcipotriene (vitamin D analog), which achieves 58-92% clearance rates within 2-4 weeks. 1, 2, 3

Specific Topical 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—either as fixed-combination product (once daily) or separate products (corticosteroid morning, vitamin D analog evening) 1, 3, 4
• The combination provides improvement within 2 weeks and maximal effect by 4 weeks 4

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) starting at 0.1-0.25% concentration, 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

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

Escalate to systemic therapy when body surface area exceeds 5%, after inadequate response to optimized topical therapy for 8 weeks, or when psoriasis significantly impacts quality of life. 5, 1, 2, 3

First-Line Systemic Treatment: Photochemotherapy (PUVA)

PUVA is the least toxic systemic agent and should be considered first-line systemic treatment. 5, 1, 2

• Start at 70% of minimum phototoxic dose (read at 72 hours) 5, 2
• Increase successive doses by 40% of the immediately preceding dose if no erythema develops 5, 2
• Response time: 4 weeks 5
• Requires ultraviolet A eye protection and shielding of genitalia unless specific need to treat 5, 1
• Contraindications: pregnancy or wish to conceive, clinically significant cataracts, age <18, previous cutaneous malignancy, previous ionizing radiation 5

Conventional Systemic Agents

Methotrexate:

• Especially useful for acute generalized pustular psoriasis, psoriatic erythroderma, psoriatic arthritis, and extensive chronic plaque psoriasis in elderly or infirm patients 5, 1
• Response time: 2 weeks 5, 2
• Dose should not exceed 0.2 mg/kg body weight 5
• Absolute contraindications: pregnancy, breastfeeding, wish to father children, significant hepatic damage, anemia, leucopenia, thrombocytopenia 5, 2, 3
• Requires contraception in both men and women 5

Cyclosporin:

• First-line for erythrodermic psoriasis with dramatic improvement during 2-3 weeks 1
• Response time: 3 weeks 5, 2
• Contraindications: abnormal renal function, uncontrolled hypertension, previous or concomitant malignancy 5, 2
• Requires blood pressure and serum creatinine monitoring 5

Acitretin (Etretinate):

• Response time: 6 weeks 5, 2
• Absolute contraindication for pregnancy or wish to conceive within 2 years of stopping treatment 5, 2
• Requires monitoring of liver function tests and fasting serum lipids 5

Biologic Therapy

Biologics achieve treatment goals in 68.2-79.3% of patients by week 16 and can be combined with methotrexate or topical high-potency corticosteroids. 1, 2

Infliximab for generalized pustular psoriasis:

• 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 (HUMIRA) dosing: 6

• Plaque psoriasis: 80 mg initial dose, followed by 40 mg every other week starting one week after initial dose
• Screen for active or latent tuberculosis, hepatitis B, and fungal infections before initiating 6
• Increased risk of serious infections and malignancy, including lymphoma 6

Special Considerations for Specific Psoriasis Subtypes

Erythrodermic psoriasis:

• Apply appropriate wet dressings with mid-potency topical steroids 1
• Maintain attention to fluid balance and rule out sepsis with blood cultures 1
• First-line systemic options: acitretin, biologic agents, cyclosporine, methotrexate 1

Pregnancy:

• NB-UVB phototherapy is first-line for pregnant women with moderate to severe psoriasis 1
• All commonly used systemic agents (methotrexate, acitretin, cyclosporine) are absolutely contraindicated in pregnancy 1

Critical Medications to ABSOLUTELY AVOID

Never prescribe systemic corticosteroids for psoriasis—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
• Salicylic acid with calcipotriene (acidic pH inactivates calcipotriene) 3

Common Pitfalls to Avoid

• Perceived "tachyphylaxis" to topical corticosteroids is often due to poor patient adherence rather than true receptor down-regulation—address compliance issues before switching therapies 3
• Patients who fail to respond to one topical agent may respond to another—trial alternative topical agents before escalating to systemic therapy 3
• Because toxicity from combination systemic treatment is at least additive, exercise extreme caution before instigating such treatment and carefully monitor these patients 5