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, combined with calcipotriene for synergistic effect 1, 2, 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
Practical Application Strategies
Fixed-combination products: Calcipotriene/betamethasone dipropionate gel or foam provides convenient once-daily application with proven efficacy for 4-12 weeks 3
Separate product regimen: Apply high-potency corticosteroid in morning and vitamin D analog in evening for enhanced effectiveness 3
Tazarotene addition: Combine tazarotene with moderate-to-high potency corticosteroids to reduce irritation while enhancing efficacy for body plaques 2, 3
Critical Safety Requirements for Topical Therapy
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 involvement exceeds 5%, with photochemotherapy (PUVA) as the least toxic systemic agent and first-line systemic treatment. 4, 1, 2
Indications for Systemic Treatment
- Body surface area involvement exceeds 5% 2, 3
- Inadequate response to optimized topical therapy after 8 weeks 2, 3
- Repeated hospital admissions for topical treatment 4
- Extensive chronic plaque psoriasis in elderly or infirm patients 4, 2
- Generalized pustular or erythrodermic psoriasis 4
- Severe psoriatic arthropathy 4, 2
First-Line Systemic Treatment: Photochemotherapy (PUVA)
PUVA is the least toxic systemic agent and should be considered first-line systemic treatment. 4, 1, 2
- Starting dose: 70% of minimum phototoxic dose (read at 72 hours) 4, 2, 3
- Dose escalation: Increase successive doses by 40% of the immediately preceding dose if there is no erythema 4, 2
- Response time: 4 weeks 4
- Required precautions: Contraception, ultraviolet A eye protection, shielding of genitalia unless specific need to treat 4, 1
- Absolute contraindications: Pregnancy or wish to conceive, clinically significant cataracts, age <18, previous cutaneous malignancy, previously received ionizing radiation 4
Conventional Systemic Agents
Methotrexate
Methotrexate is especially useful in acute generalized pustular psoriasis, psoriatic erythroderma, psoriatic arthritis, and extensive chronic plaque psoriasis in elderly or infirm patients, with a response time of 2 weeks. 4, 1, 2
- Response time: 2 weeks 4, 2, 3
- Absolute contraindications: Pregnancy, breastfeeding, wish to father children, significant hepatic damage, anemia, leucopenia, thrombocytopenia 4, 2, 3
- Required monitoring: Contraception (men and women), avoid drugs which interact, full blood count, liver function tests 4, 2
- Dosing: Maximum 0.2 mg/kg body weight, increased gradually from first dose 4
Cyclosporin
Cyclosporin is first-line for erythrodermic psoriasis, with dramatic improvement during 2-3 weeks. 1
- Response time: 3 weeks 4, 2, 3
- Absolute contraindications: Abnormal renal function, uncontrolled hypertension, previous or concomitant malignancy 4, 2, 3
- Required monitoring: Contraception, measure blood pressure, serum creatinine 4, 2
Acitretin (Etretinate)
- Response time: 6 weeks 4, 2, 3
- Absolute contraindications: Pregnancy or wish to conceive within 2 years of stopping treatment 4, 2, 3
- Required monitoring: Contraception, liver function tests and fasting serum lipids 4, 2
Biologic Therapy
Biologics (adalimumab, infliximab, ustekinumab, etanercept) 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
Adalimumab (HUMIRA) Dosing by Indication
- Psoriatic arthritis: 40 mg every other week 5
- Plaque psoriasis: 80 mg initial dose, followed by 40 mg every other week starting one week after initial dose 5
- Can be combined with methotrexate or topical high-potency corticosteroids for enhanced efficacy 1, 2
Critical Safety Considerations for Biologics
- Increased risk of serious infections leading to hospitalization or death, including tuberculosis, bacterial sepsis, invasive fungal infections 5
- Perform test for latent TB; if positive, start treatment for TB prior to starting biologic 5
- Monitor all patients for active TB during treatment, even if initial latent TB test is negative 5
- Lymphoma and other malignancies, some fatal, have been reported in patients treated with TNF blockers 5
Special Considerations for Pustular Psoriasis
Infliximab 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 2, 3
- Alternative option: Consider acitretin as an alternative treatment 2, 3
Critical Medications to ABSOLUTELY AVOID
Systemic Corticosteroids
Systemic corticosteroids should never be prescribed for psoriasis, as they precipitate erythrodermic psoriasis, generalized pustular psoriasis, or very unstable disease upon discontinuation. 1, 2, 3
Other Medications That Worsen Psoriasis
Lithium, chloroquine, and mepacrine are associated with severe, potentially fatal psoriasis deterioration and should be avoided. 1, 2, 3
- 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 2
Patients who fail to respond to one topical agent may respond to another; trial alternative topical agents before escalating to systemic therapy 2
Implement periods each year when alternative treatments are employed to prevent tachyphylaxis 2
For combination treatment toxicity: Because toxicity from any combination treatment is at least additive, extreme caution should be exercised with careful monitoring 4