What are the treatment options for a patient with psoriasis?

Psoriasis Treatment Algorithm

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; for moderate-to-severe disease (≥5% BSA), escalate to phototherapy (PUVA) as first-line systemic treatment, or consider methotrexate, biologics, or other conventional systemic agents based on specific clinical scenarios. 1, 2, 3

Topical Therapy for Mild Disease (<5% BSA)

First-Line Topical Regimen

• Apply clobetasol propionate 0.05% or betamethasone dipropionate 0.05% twice daily to thick body plaques for maximum 2-4 weeks, combined with calcipotriene for synergistic effect 1, 2, 3
• Use fixed-combination calcipotriene/betamethasone dipropionate gel or foam once daily for convenient application with proven efficacy for 4-12 weeks 3
• Alternative separate product regimen: apply high-potency corticosteroid in morning and vitamin D analog in evening 3

Site-Specific Modifications

• Face, genitals, intertriginous areas: Use low-potency corticosteroids or topical calcineurin inhibitors to minimize atrophy risk 1, 3
• Scalp involvement: Apply clobetasol propionate 0.05% shampoo twice weekly for rapid symptom relief within 3-4 weeks 3
• Body plaques with irritation: Add tazarotene to moderate-to-high potency corticosteroids to reduce irritation while enhancing efficacy 1, 3

Critical Safety Monitoring 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 1, 3
• Require dermatological supervision for class 1-2 preparations 3
• Implement periods each year when alternative treatments are employed to prevent tachyphylaxis 1

Alternative Topical Options When First-Line Fails

• Start with 0.5-1.0% crude coal tar in petroleum jelly and increase concentration every few days to maximum 10% 1
• Dithranol (Anthralin): Start at 0.1-0.25% concentration and increase in doubling concentrations as tolerated, using short contact mode (15-45 minutes every 24 hours) 1

Indications for Escalation to Systemic Therapy

Escalate when any of the following criteria are met:

• Body surface area involvement exceeds 5% 1, 2
• Inadequate response to optimized topical therapy after 8 weeks 1
• Failure of adequate trial of topical treatment or repeated hospital admissions for topical treatment 4
• Generalized pustular or erythrodermic psoriasis (medical emergency) 4, 2
• Severe psoriatic arthropathy requiring systemic treatment 4, 1
• Extensive chronic plaque psoriasis in elderly or infirm patients 4, 1
• Psoriasis in vulnerable areas (face, genitals, hands, feet, scalp, intertriginous) unresponsive to topical therapy or causing major quality-of-life issues 4

Systemic Therapy Selection Algorithm

First-Line Systemic: Photochemotherapy (PUVA)

• PUVA is the least toxic systemic agent and should be considered first-line systemic treatment 1, 2
• Starting dose: 70% of minimum phototoxic dose (read at 72 hours), with successive doses increased by 40% of the preceding dose if no erythema develops 4, 1, 2
• Response time: 4 weeks 4
• Contraindications: Pregnancy or wish to conceive, clinically significant cataracts, age <18, previous cutaneous malignancy, previously received ionizing radiation 4
• Required precautions: Contraception, ultraviolet A eye protection, shielding of genitalia unless specific need to treat 4, 2

Conventional Systemic Agents

Methotrexate

• Especially useful for: Acute generalized pustular psoriasis, psoriatic erythroderma, psoriatic arthritis, extensive chronic plaque psoriasis in elderly or infirm patients 4, 1, 2
• Response time: 2 weeks 4, 1, 2
• Dose: Maximum 0.2 mg/kg body weight, increased gradually from first dose 4
• Absolute contraindications: Pregnancy, breastfeeding, wish to father children, significant hepatic damage, anemia, leucopenia, thrombocytopenia 4, 1, 2
• Required monitoring: Contraception (men and women), avoid drugs which interact, full blood count, liver function tests 4, 1

Cyclosporine

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

Acitretin (Etretinate)

• Response time: 6 weeks 4, 1, 2
• Consider as alternative for pustular psoriasis 1, 3
• Absolute contraindication: Pregnancy or wish to conceive within 2 years of stopping treatment 4, 1, 2
• Required monitoring: Contraception, liver function tests, fasting serum lipids 4, 1

Biologic Therapy

General Biologic Considerations

• Biologics (adalimumab, infliximab, ustekinumab, etanercept) achieve treatment goals in 68.2-79.3% of patients by week 16 1, 2
• Can be combined with methotrexate or topical high-potency corticosteroids 1
• Required screening: Active or latent tuberculosis, hepatitis B, fungal infections 1
• Safety concerns: Increased risk of serious infections and cancer 1, 5

Adalimumab (HUMIRA)

• 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: 80 mg initial dose, followed by 40 mg every other week starting one week after initial dose 5
• Boxed Warning: Serious infections leading to hospitalization or death, including tuberculosis, bacterial sepsis, invasive fungal infections; lymphoma and other malignancies reported 5
• Contraindication: Do not start during active infection; discontinue if serious infection develops 5

Infliximab for Generalized Pustular Psoriasis

• Demonstrates rapid and often complete disease clearance for generalized pustular psoriasis 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 1, 3

Special Clinical Scenarios

Erythrodermic Psoriasis (Medical Emergency)

• Initial management: Apply appropriate wet dressings with mid-potency topical steroids, maintain attention to fluid balance, rule out sepsis with blood cultures 2
• First-line systemic options: Acitretin, biologic agents, cyclosporine (with dramatic improvement in 2-3 weeks), methotrexate 2

Generalized Pustular Psoriasis

• Avoid systemic corticosteroids due to risk of disease exacerbation upon discontinuation 1, 3
• Consider infliximab as first-line biologic therapy or acitretin as alternative 1, 2, 3

Pregnancy

• NB-UVB phototherapy is first-line for pregnant women with moderate to severe psoriasis, as it lacks systemic toxicities and immunosuppressive properties 2
• All commonly used systemic agents (methotrexate, acitretin, cyclosporine) are absolutely contraindicated in pregnancy 2

Psoriatic Arthritis

• Methotrexate is especially useful 4, 1, 2
• Adalimumab FDA-approved for reducing signs and symptoms, inhibiting structural damage progression, and improving physical function 5
• Dosing: 40 mg every other week; some patients not receiving methotrexate may benefit from 40 mg every week or 80 mg every other week 5

Critical Medications to ABSOLUTELY AVOID

Never Prescribe

• Systemic corticosteroids: Can precipitate erythrodermic psoriasis, generalized pustular psoriasis, or very unstable psoriasis when discontinued—potentially fatal deterioration 1, 2, 3
• Lithium, chloroquine, mepacrine: Associated with severe, potentially fatal psoriasis deterioration 1, 2, 3

Use with Caution or Avoid

• Beta-blockers and NSAIDs: May worsen psoriasis in some patients 3
• Alcohol: Can precipitate or worsen psoriasis 3
• Salicylic acid with calcipotriene: Acidic pH inactivates calcipotriene and reduces effectiveness 3

Common Pitfalls and How to Avoid Them

• Perceived "tachyphylaxis" to topical corticosteroids is often due to poor patient adherence rather than true receptor down-regulation—address compliance issues before switching therapies 1
• Patients who fail to respond to one topical agent may respond to another—trial alternative topical agents before escalating to systemic therapy 1
• Combination therapy toxicity is at least additive—exercise extreme caution before instigating combination systemic treatments with careful monitoring 4
• For patients with <5% BSA but major quality-of-life issues or vulnerable area involvement (face, genitals, hands, feet), systemic therapy may be warranted from onset 4