What are the treatment options for a patient with psoriasis?

Treatment for Psoriasis

Initial Treatment Selection Based on Disease Severity

For 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

Topical Therapy Algorithm for Mild Disease

Body plaques:

• Apply clobetasol propionate 0.05% or betamethasone dipropionate 0.05% twice daily for maximum 2-4 weeks 1, 2
• Combine with calcipotriene for synergistic effect superior to either agent alone 1, 2
• Fixed-combination products (calcipotriene/betamethasone dipropionate gel or foam) provide convenient once-daily application for 4-12 weeks 2
• Alternative regimen: apply high-potency corticosteroid in morning and vitamin D analog in evening 2

Scalp involvement:

• Use clobetasol propionate 0.05% shampoo twice weekly, providing rapid symptom relief within 3-4 weeks 2

Face, genitals, and intertriginous areas:

• Apply low-potency corticosteroids or topical calcineurin inhibitors to minimize atrophy risk 1, 2

Thick resistant plaques:

• Add tazarotene to moderate-to-high potency corticosteroids to reduce irritation while enhancing efficacy 1, 2

Critical Safety Requirements for Topical Corticosteroids

• Implement mandatory clinical review every 4 weeks during active treatment with no unsupervised repeat prescriptions for high-potency agents 2
• Limit moderate-potency corticosteroid use to maximum 100g per month 1, 2
• Require dermatological supervision for class 1-2 preparations 2
• Implement periods each year when alternative treatments are employed to prevent tachyphylaxis 1

Common pitfall: Perceived "tachyphylaxis" to topical corticosteroids is usually poor patient adherence rather than true receptor down-regulation—address compliance issues before switching therapies 1, 3

Systemic Treatment for Moderate-to-Severe Disease

Escalate to systemic therapy when body surface area involvement exceeds 5%, inadequate response to optimized topical therapy after 8 weeks, or signs of erythrodermic or pustular psoriasis develop. 1, 2

First-Line Systemic Treatment

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

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

Conventional Systemic Agents

When PUVA is contraindicated or ineffective, select from these options based on specific clinical scenarios:

Methotrexate:

• Response time: 2 weeks 4, 1, 2
• Especially useful in acute generalized pustular psoriasis, psoriatic erythroderma, psoriatic arthritis, and extensive chronic plaque psoriasis in elderly or infirm patients 4
• Absolute contraindications: pregnancy, breastfeeding, wish to father children, significant hepatic damage, anemia, leucopenia, thrombocytopenia 4, 1, 2
• Avoid conception in male patients until 3 months after discontinuation 4
• Synergistic effect when combined with BB-UVB, NB-UVB, or PUVA, allowing enhanced efficacy and reduced treatment duration 4

Cyclosporine:

• Response time: 3 weeks 4, 1, 2
• First-line for erythrodermic psoriasis with dramatic improvement during 2-3 weeks 4
• Use short 3-4 month "interventional" course, especially in patients with renal disease, hypertension, or those on medications that influence cyclosporine levels 4, 1
• Contraindications: abnormal renal function, uncontrolled hypertension, previous or concomitant malignancy 4, 2
• Monitor blood pressure and serum creatinine 4

Acitretin (Etretinate):

• Response time: 6 weeks 4, 1, 2
• Effective in combination with NB-UVB or PUVA, increasing response rates and decreasing total number of treatments 4
• Suppresses development of cutaneous squamous cell carcinoma in patients treated with PUVA 4
• Absolute contraindication: pregnancy or wish to conceive within 2 years of stopping treatment 4, 2
• Slow onset of action may limit usefulness in erythrodermic psoriasis requiring rapid response 4

Biologic Therapy

For moderate-to-severe psoriasis failing conventional systemic agents:

• Biologics (adalimumab, infliximab, ustekinumab, etanercept) achieve treatment goals in 68.2-79.3% of patients by week 16 1
• Can be combined with methotrexate or topical high-potency corticosteroids 1
• Screen for active or latent tuberculosis, hepatitis B, and fungal infections before initiating 1
• Monitor for increased risk of serious infections and cancer 1

For generalized pustular psoriasis specifically:

• Infliximab demonstrates rapid and often complete disease clearance and should be considered first-line biologic therapy 1, 2
• Standard dosing: 5 mg/kg infused at weeks 0,2, and 6, then every 8 weeks thereafter 1, 2

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 worsen psoriasis and should be avoided:

• Lithium, chloroquine, and mepacrine: associated with severe, potentially fatal psoriasis deterioration 4, 1, 2, 3
• Beta-blockers and NSAIDs: may worsen psoriasis in some patients 4, 2, 3
• Alcohol: can precipitate or worsen psoriasis 4, 2, 3
• Salicylic acid with calcipotriene: acidic pH inactivates calcipotriene and reduces effectiveness 2

Special Considerations for Erythrodermic Psoriasis

Initial management for all patients:

• Apply appropriate wet dressings with mid-potency topical steroids 4
• Maintain attention to fluid balance with control of ankle edema 4
• Rule out sepsis with blood cultures 4

First-line systemic options (in alphabetical order):

• Acitretin 4
• Biologic agents (infliximab, adalimumab, ustekinumab) 4
• Cyclosporine approximately 3-4 month course 4
• Methotrexate 4

Pregnancy Considerations

NB-UVB phototherapy is first-line for pregnant women with moderate to severe psoriasis, as it lacks systemic toxicities and immunosuppressive properties. 4

All commonly used systemic agents (methotrexate, acitretin, cyclosporine) are absolutely contraindicated in pregnancy 4

Alternative Topical Options When First-Line Fails

Coal tar preparations:

• Start with 0.5-1.0% crude coal tar in petroleum jelly 1
• Increase concentration every few days to maximum 10% 1

Dithranol (Anthralin):

• Start at 0.1-0.25% concentration 1
• Increase in doubling concentrations as tolerated 1
• Short contact mode: leave on skin for only 15-45 minutes every 24 hours 1