What are the treatment guidelines for psoriasis?

Treatment Guidelines for Psoriasis

For mild psoriasis (<5% body surface area), start with topical corticosteroids combined with vitamin D analogs as first-line therapy; for moderate-to-severe disease (≥5% BSA), advance to narrowband UVB phototherapy, and reserve systemic agents (methotrexate, cyclosporine, acitretin) or biologics (TNF inhibitors, IL-17/IL-23 inhibitors) for severe, refractory, or disabling disease. 1, 2

Disease Severity Classification

• Mild psoriasis is defined as <5% body surface area involvement, while moderate-to-severe is ≥5% BSA or involvement of vulnerable areas (face, genitals, hands, feet) 1, 2
• Patients with symptomatic psoriasis causing pain, bleeding, or itching should be considered for systemic or phototherapy even if BSA is limited 1, 2
• Quality of life impact must drive treatment decisions, as psychological distress can be severe regardless of physical extent 1, 2

Topical Therapy for Mild Disease

Topical corticosteroids are the cornerstone of treatment for mild psoriasis 3, 1

• Use ultra-high potency (Class I) corticosteroids like clobetasol or halobetasol for thick plaques on trunk and extremities, achieving 58-92% improvement rates 3
• Apply low-potency corticosteroids to facial and intertriginous areas to avoid skin atrophy 1, 2
• Limit moderately potent preparations to no more than 100g per month 2
• Require regular clinical review with no unsupervised repeat prescriptions 2

Vitamin D analogs enhance efficacy and reduce corticosteroid side effects 1, 2

• Use calcipotriene (maximum 100g per week to avoid hypercalcemia) or calcitriol (less irritating for sensitive areas) 2
• Combination calcipotriene/betamethasone dipropionate products simplify regimens, improve compliance, and provide superior efficacy compared to monotherapy 1, 2, 4
• Apply vitamin D analogs after phototherapy to avoid inactivation 2

Additional topical options include:

• Coal tar, anthralin, and salicylic acid for keratolytic effects 1
• Tazarotene (topical retinoid) for plaque psoriasis 5

Phototherapy for Moderate-to-Severe Disease

Narrowband UVB is first-line phototherapy for moderate-to-severe psoriasis 1, 2

• Treatments should be given no more frequently than every 48 hours 3
• Courses typically last 8-10 weeks 3
• Increase successive doses by 40% if no erythema, 20% if slight erythema, or hold at same exposure if more than slight erythema 3

PUVA (psoralen plus UVA) is the least toxic systemic option 3

• Start at 70% of minimum phototoxic dose (read at 72 hours) 3
• Increase by 40% of preceding dose if no erythema 3
• Response typically occurs within 4 weeks 3
• Requires contraception, UV eye protection, and genital shielding 3

308-nm excimer laser targets localized resistant areas 2

Critical phototherapy requirements:

• Senior clinician supervision with adequate training 3
• Properly maintained and calibrated equipment 3
• Accurate dosage records for each patient 3

Avoid commercial sunbeds (emit UVA), which are rarely effective and cause premature aging and skin fragility 3

Systemic Therapy for Severe or Refractory Disease

The decision to use systemic therapy must be made by a senior dermatologist based on objective severity, social factors, and psychological impact 3

Indications for Systemic Treatment:

• Failure of adequate topical therapy trial 3
• Repeated hospital admissions for topical treatment 3
• Extensive chronic plaque psoriasis in elderly or infirm patients 3
• Generalized pustular or erythrodermic psoriasis 3
• Severe psoriatic arthropathy 3

Traditional Systemic Agents:

Methotrexate is first-line for moderate-to-severe psoriasis 6

• Start at 15 mg weekly, maximum 25-30 mg weekly 6
• Response within 2 weeks 3
• Requires baseline and regular liver function monitoring 3, 6
• Effective for both skin and psoriatic arthritis 6

Cyclosporine provides rapid response 6

• Dose: 2.5-5 mg/kg daily 6
• Response within 3 weeks 6
• Requires baseline and regular blood pressure and renal function monitoring 6

Acitretin is particularly effective for pustular psoriasis 6

• Dose: 25-50 mg daily 6
• Requires baseline CBC, lipids, and liver function tests with regular monitoring 6

Biologic Agents:

TNF inhibitors, IL-17 inhibitors, IL-23 inhibitors, and IL-12/23 inhibitors are third-line for moderate-to-severe psoriasis 1

• Adalimumab (TNF inhibitor) is 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 7
• Adalimumab is also effective for psoriatic arthritis, reducing signs/symptoms, inhibiting structural damage, and improving physical function 1, 7

Special Psoriasis Subtypes

Guttate psoriasis is often self-limiting 3

• Use low concentrations of tar and dithranol (less tolerant of treatment) 3
• Ultraviolet B radiation is especially helpful 3
• Investigate and treat streptococcal infection with phenoxymethylpenicillin or erythromycin 3
• Consider tonsillectomy for repeated attacks after documented tonsillitis 3

Localized pustular psoriasis of palms/soles has unsatisfactory treatment options 3

• Use moderately potent topical corticosteroid (Grade III) 3
• Consider topical coal tar, dithranol, or systemic etretinate 3

Generalized pustular and erythrodermic psoriasis require hospitalization and systemic agents 3

Scalp psoriasis:

• Use calcipotriene foam or calcipotriene/betamethasone dipropionate gel for 4-12 weeks 1, 2
• Consider excimer laser for resistant cases 2

Critical Safety Considerations

All systemic agents are absolutely contraindicated in pregnancy 3

• Explain risks to women of childbearing age and ensure contraception 3

Avoid systemic corticosteroids as they cause disease flare during taper 1, 2

Long-term potent topical corticosteroids cause skin atrophy, striae, and telangiectasia 1, 2

Drugs that worsen psoriasis: alcohol, beta-blockers, NSAIDs, lithium, chloroquine, mepacrine 1, 2

Combination systemic therapy has at least additive toxicity; exercise extreme caution 3

Combination and Rotational Strategies

Combination therapy with topical corticosteroids plus vitamin D analogs enhances efficacy and reduces irritation 1, 2

Rotational therapy (switching treatment modalities every 1-2 years) minimizes cumulative toxicity 1, 2

Multiple topical agents can be used concurrently at different times of day, but avoid incompatible combinations (e.g., calcipotriene with lactic acid products that alter pH) 3

Adjunctive Therapies

Oral curcumin supplementation may benefit as adjunctive therapy 1, 6

Fish oil/omega-3 fatty acids may augment topical, systemic, and phototherapy effects 6