Management of Skin Psoriasis
For mild psoriasis (≤5% body surface area), initiate treatment with high-potency topical corticosteroids combined with calcipotriene, which achieves 58-92% clearance rates and represents the most effective first-line approach. 1, 2
Initial Treatment Strategy for Mild Disease
Topical Corticosteroid Selection by Body Site
For body plaques: Apply clobetasol propionate 0.05% or betamethasone dipropionate 0.05% twice daily for a maximum of 2-4 weeks, combined with calcipotriene for synergistic effect 1, 2
For scalp involvement: Use clobetasol propionate 0.05% shampoo twice weekly, providing rapid symptom relief within 3-4 weeks 2
For face, genitals, and intertriginous areas: Apply low-potency corticosteroids or topical calcineurin inhibitors to minimize atrophy risk 2
Combination Regimens for Enhanced Efficacy
Fixed-combination products such as calcipotriene/betamethasone dipropionate gel or foam provide convenient once-daily application with proven efficacy for 4-12 weeks 2
Separate product regimen: Apply high-potency corticosteroid in the morning and vitamin D analog in the evening for enhanced effectiveness 2
Tazarotene addition: Combine tazarotene with moderate-to-high potency corticosteroids to reduce irritation while enhancing efficacy for body plaques 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, 2 This prevents the common pitfall of prolonged unsupervised use leading to skin atrophy and systemic absorption.
Limit moderate-potency corticosteroid use to maximum 100g per month 3, 2
Require dermatological supervision for class 1-2 (very potent/potent) preparations 3, 2
Implement periods each year when alternative treatments are employed to prevent tachyphylaxis 4
Alternative Topical Options When First-Line Fails
If patients fail to respond to corticosteroid/calcipotriene combinations, trial alternative topical agents before escalating to systemic therapy, as some patients who fail one agent will respond to another. 3, 4
Coal tar: Start with 0.5-1.0% crude coal tar in petroleum jelly and increase concentration every few days to maximum 10% 3, 4
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) to minimize irritancy and staining 3
Systemic Treatment for Moderate-to-Severe Disease
Escalate to systemic therapy when body surface area involvement exceeds 5%, when there is inadequate response to optimized topical therapy after 8 weeks, or when signs of erythrodermic or pustular psoriasis develop. 2, 4
First-Line Systemic Agent
Photochemotherapy (PUVA) is the least toxic systemic agent and should be considered first-line systemic treatment. 1, 2, 4 Start at 70% of minimum phototoxic dose and increase successive doses by 40% if no erythema develops. 2, 4 Patients require ultraviolet A eye protection and shielding of genitalia. 1
Conventional Systemic Agents
When phototherapy is insufficient or inappropriate, select from the following based on clinical presentation:
Methotrexate: Response time 2 weeks; especially useful in acute generalized pustular psoriasis, psoriatic erythroderma, psoriatic arthritis, and extensive chronic plaque psoriasis 3, 1, 2
- Absolute contraindications: pregnancy, breastfeeding, wish to father children, significant hepatic damage, anemia, leucopenia, thrombocytopenia 2
- Start with doses not exceeding 0.2 mg/kg body weight for first dose 3
- Requires weekly monitoring initially (full blood count, liver function tests, renal function), then every 1-2 months when stable 3
Acitretin (etretinate): Response time 6 weeks; requires contraception with absolute contraindication for pregnancy or wish to conceive within 2 years of stopping treatment due to teratogenic potential 3, 2
Cyclosporine: Response time 3 weeks; first-line for erythrodermic psoriasis with dramatic improvement during 2-3 weeks 1, 5
- Initial dose 2.5 mg/kg/day divided twice daily, increase by 0.5 mg/kg/day every 2 weeks to maximum 4 mg/kg/day based on response 5
- Contraindicated with abnormal renal function, uncontrolled hypertension, or malignancy 2
- Discontinue if satisfactory response not achieved after 6 weeks at maximum tolerated dose 5
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
Special Indication 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, 4 Standard dosing is 5 mg/kg infused at weeks 0,2, and 6, then every 8 weeks thereafter. 2
Critical Safety Screening for Biologics
Before initiating biologic therapy, screen for active or latent tuberculosis, hepatitis B, and fungal infections, as biologics increase risk of serious infections and cancer. 4, 6
Medications That Must Be Absolutely Avoided
Never prescribe systemic corticosteroids for psoriasis, as they precipitate erythrodermic psoriasis, generalized pustular psoriasis, or very unstable disease upon discontinuation. 1, 2, 4 This represents a potentially fatal complication.
Additional medications to avoid:
Lithium, chloroquine, and mepacrine are associated with severe, potentially fatal psoriasis deterioration 3, 2
Beta-blockers and NSAIDs may worsen psoriasis in some patients 3, 2
Common Pitfalls to Avoid
Perceived "tachyphylaxis" to topical corticosteroids is often due to poor patient adherence rather than true receptor down-regulation. 4 Address compliance issues before switching therapies or escalating to systemic treatment.
When using occlusive dressings with topical corticosteroids for recalcitrant psoriasis, apply in the evening and remove in the morning (12-hour occlusion), but discontinue if infection develops. 7