What are the treatment options for a patient with psoriasis?

Psoriasis Treatment Algorithm

For mild psoriasis (<5% body surface area), initiate high-potency topical corticosteroids combined with calcipotriene twice daily for 2-4 weeks; for moderate-to-severe disease (≥5% BSA), escalate to phototherapy (PUVA) as first-line systemic treatment, or consider biologics like adalimumab or infliximab when systemic therapy is indicated. 1, 2

Mild Psoriasis: Topical Therapy First-Line

Body and Limb Plaques

• Apply clobetasol propionate 0.05% or betamethasone dipropionate 0.05% twice daily to thick plaques for maximum 2-4 weeks 1, 2
• Combine with calcipotriene (vitamin D analog) for synergistic effect, achieving 58-92% clearance rates—superior to either agent alone 1, 3
• 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

Sensitive Areas (Face, Genitals, Intertriginous Regions)

• Use low-potency corticosteroids or topical calcineurin inhibitors (tacrolimus, pimecrolimus) to minimize atrophy risk 1, 2
• Never use high-potency steroids on these areas due to increased absorption and atrophy risk 1

Scalp Involvement

• Apply clobetasol propionate 0.05% shampoo twice weekly for rapid symptom relief within 3-4 weeks 2

Critical Safety Monitoring

• 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
• Implement periods each year when alternative treatments are employed to prevent tachyphylaxis 1

Alternative Topical Options When First-Line Fails

• Add tazarotene to moderate-to-high potency corticosteroids for body plaques to reduce irritation while enhancing efficacy 1, 2
• Start crude coal tar at 0.5-1.0% in petroleum jelly, increasing concentration every few days to maximum 10% 1
• Dithranol (anthralin) can be started at 0.1-0.25% concentration in short contact mode (15-45 minutes every 24 hours) 1

Moderate-to-Severe Psoriasis: Systemic Therapy Indications

Escalate to systemic therapy when: 1, 2

• Body surface area involvement exceeds 5%
• Inadequate response to optimized topical therapy after 8 weeks
• Repeated hospital admissions for topical treatment 4
• Extensive chronic plaque psoriasis in elderly or infirm patients 4, 1
• Generalized pustular or erythrodermic psoriasis 4
• Severe psoriatic arthropathy 4, 1

First-Line Systemic Treatment: Phototherapy (PUVA)

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

Dosing protocol: 4, 1

• Start at 70% of minimum phototoxic dose (read at 72 hours)
• Increase successive doses by 40% of preceding dose if no erythema develops
• Expect response within 4 weeks 4, 1
• Treatment typically given 2-3 times weekly 4

Combination strategies to enhance efficacy: 4

• Methotrexate with PUVA produces synergistic effect, allowing enhanced efficacy and reduced cumulative UV doses
• Acitretin with PUVA increases response rates and decreases total number of treatments
• Oral retinoids suppress development of cutaneous squamous cell carcinoma in PUVA-treated patients 4

Important consideration: Narrow-band UVB is particularly useful for pregnancy and should be considered first-line for pregnant women with moderate-to-severe disease 4

Conventional Systemic Agents

Methotrexate

• Response time: 2 weeks 4, 1
• 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 (avoid conception until 3 months after discontinuation), significant hepatic damage, anemia, leucopenia, thrombocytopenia 4, 1
• Dose should not exceed 0.2 mg/kg body weight 4
• Subcutaneous administration bypasses the liver and may be reasonable choice 4
• Critical drug interaction: avoid trimethoprim-sulfamethoxazole and other drugs that interact with methotrexate 4

Cyclosporine

• Response time: 3 weeks 4, 1
• For erythrodermic psoriasis, cyclosporine 4 mg/kg/day is first-line, producing dramatic improvement within 2-3 weeks 4
• Generally only a short 3-4 month "interventional" course is indicated, especially in patients with renal disease, hypertension, or those on medications that influence cyclosporine levels 4
• Contraindications: abnormal renal function, uncontrolled hypertension, previous or concomitant malignancy 4, 1
• Monitor blood pressure and serum creatinine regularly 4, 1

Acitretin (Etretinate)

• Response time: 6 weeks 4, 1
• Slow onset of action may limit usefulness in patients requiring rapid response (e.g., erythrodermic psoriasis) 4
• Absolute contraindication: pregnancy or wish to conceive within 2 years of stopping treatment due to teratogenicity 4, 1
• Requires contraception and monitoring of liver function tests and fasting serum lipids 4, 1

Biologic Therapy

Adalimumab (TNF-α Inhibitor)

FDA-approved for moderate-to-severe chronic plaque psoriasis in adults who are candidates for systemic therapy or phototherapy when other systemic therapies are medically less appropriate 5

Dosing: 5

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

Efficacy: 1

• Can be combined with methotrexate or topical high-potency corticosteroids
• Achieves treatment goals in 68.2-79.3% of patients by week 16

Critical safety considerations: 5

• Screen for active or latent tuberculosis before initiating; if positive, start TB treatment prior to starting adalimumab
• Screen for hepatitis B and fungal infections
• Increased risk of serious infections leading to hospitalization or death
• Black Box Warning: Lymphoma and other malignancies, some fatal, have been reported in children and adolescents treated with TNF blockers
• Post-marketing cases of hepatosplenic T-cell lymphoma (rare but fatal) in adolescents and young adults with inflammatory bowel disease
• Discontinue if patient develops serious infection or sepsis during treatment

Infliximab (TNF-α Inhibitor)

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

Dosing: 1, 2

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

Alternative for pustular psoriasis: Consider acitretin as alternative treatment option 1, 2

Ustekinumab (IL-12/23 Inhibitor)

Listed as first-line biologic option for erythrodermic psoriasis 4

Special Situations

Erythrodermic Psoriasis

Initial management for all patients: 4

• Appropriate wet dressings with mid-potency topical steroids
• Attention to fluid balance with control of ankle edema
• Rule out sepsis with blood cultures

First-line systemic treatment algorithm: 4

1. Cyclosporine 4 mg/kg/day for 3-4 month course (produces dramatic improvement in 2-3 weeks)
2. Alternative first-line options: Infliximab, Adalimumab, Ustekinumab
3. Second-line options: Acitretin, Methotrexate, Etanercept, or combination therapies

Acitretin limitations: Slow onset may not improve disease rapidly enough in systemically ill patients 4

Methotrexate considerations: Subcutaneous administration bypasses liver, but need to upwardly titrate may limit usefulness in patients requiring rapid response 4

Pustular Psoriasis

• Avoid systemic corticosteroids due to risk of disease exacerbation upon discontinuation 1, 2
• Infliximab is first-line biologic 1, 2
• Acitretin is alternative option 1, 2

Pregnancy

• Narrow-band UVB is first-line for moderate-to-severe psoriasis in pregnancy 4
• Avoid methotrexate, acitretin, and biologics 4

Psoriatic Arthritis

• Methotrexate is especially useful 4
• Adalimumab FDA-approved for reducing signs and symptoms, inhibiting structural damage progression, and improving physical function 5
• TNF-α inhibitors are first-line biologic options 4

Critical Medications to ABSOLUTELY AVOID

Never Prescribe for Psoriasis:

• Systemic corticosteroids: precipitate erythrodermic psoriasis, generalized pustular psoriasis, or very unstable disease upon discontinuation 1, 2, 6
• Lithium, chloroquine, mepacrine: associated with severe, potentially fatal psoriasis deterioration 1, 2, 6

Medications That May Worsen Psoriasis:

• Beta-blockers and NSAIDs may worsen psoriasis in some patients 2, 6
• Alcohol can precipitate or worsen psoriasis 2, 6

Drug Interaction to Avoid:

• Salicylic acid with calcipotriene: acidic pH inactivates calcipotriene and reduces effectiveness 2

Common Pitfalls and How to Avoid Them

Perceived "Tachyphylaxis" to Topical Corticosteroids

This is usually poor patient adherence, not true receptor down-regulation 1, 6

• Address compliance issues before switching therapies 1, 6
• Implement mandatory clinical review every 4 weeks 2
• Consider fixed-combination products for improved adherence 2

Premature Escalation to Systemic Therapy

• Patients who fail one topical agent may respond to another—trial alternative topical agents before escalating 1, 6
• Ensure adequate trial duration (8 weeks of optimized topical therapy) before declaring failure 1, 2

Inadequate Monitoring of Systemic Agents

• Methotrexate: monitor for hepatic fibrosis related to cumulative lifetime dosage 4
• Cyclosporine: measure blood pressure and serum creatinine regularly 4, 1
• Acitretin: monitor liver function tests and fasting serum lipids 4, 1
• Biologics: screen for latent TB, hepatitis B, and fungal infections before initiating 5

Combination Therapy Toxicity

Toxicity from combination treatment is at least additive—exercise extreme caution before instigating combination systemic therapy 4