What are the treatment options for a patient with psoriasis of the scalp?

Treatment of Scalp Psoriasis

Start with combination calcipotriene/betamethasone dipropionate gel or foam as first-line therapy, applied once daily for up to 52 weeks, which achieves 69-74% clear or almost clear status with no serious adverse events. 1

First-Line Topical Treatment Algorithm

Preferred Initial Regimen

• Calcipotriene 0.005% plus betamethasone dipropionate 0.064% gel or foam is the optimal first-line choice because it combines rapid corticosteroid action with vitamin D analog efficacy, achieving superior results (69-74% clear/almost clear) compared to either agent alone (27% with vehicle). 1, 2
• Apply once daily for 4-12 weeks initially, with safety data supporting use up to 52 weeks without hypothalamic-pituitary-adrenal axis suppression or striae formation. 1

Alternative Monotherapy Options

If combination therapy is unavailable or not tolerated:

High-potency topical corticosteroids (Class 1-2):

• Clobetasol propionate 0.05% shampoo provides rapid relief within 3-4 weeks for moderate-to-severe scalp psoriasis. 2
• Apply 1-2 times daily for up to 4 weeks, then taper frequency after clinical improvement to prevent rebound. 1
• Efficacy rates range from 41-92% depending on potency class used. 1

Calcipotriene foam monotherapy:

• Achieves 40.9% clear/almost clear status at 8 weeks (note: vitamin D analogs show efficacy at 8 weeks but not at 4 weeks). 1
• Apply after phototherapy if using both modalities, as UVA radiation decreases calcipotriene concentration on skin. 1

Vehicle Selection Matters for Adherence

Use scalp-specific formulations (solutions, foams, shampoos, sprays) rather than creams or ointments because they improve both adherence and efficacy. 1 Poor adherence is common due to inconvenience, time constraints, and frustration with messy formulations. 1

• African American patients often prefer oil-based preparations for scalp compatibility with routine hair care. 3
• The most appropriate vehicle is the one the patient will actually use consistently. 3

Treatment Duration and Monitoring

• Initial treatment with high-potency corticosteroids: maximum 4 weeks before clinical review is mandatory. 1, 2
• Longer-term use (>12 weeks) requires careful physician supervision with gradual reduction in frequency after improvement. 1
• No unsupervised repeat prescriptions should be allowed for high-potency agents. 2
• Monitor for adverse effects including skin atrophy, striae, folliculitis, telangiectasia, purpura, and burning/stinging sensation. 1

When to Escalate to Systemic Therapy

Consider systemic therapy when:

• Topical treatment fails after 8 weeks of optimized therapy. 2
• Body surface area involvement exceeds 5%. 2
• Scalp psoriasis causes symptomatic disease or more than minimal quality-of-life impact despite topical therapy (European League Against Rheumatism considers scalp a "vulnerable area" warranting systemic treatment). 1

Systemic Options in Order of Consideration:

1. Narrowband UVB phototherapy (2-3 visits weekly for 20-30 treatments) - well-tolerated and cost-effective, though has limitations in improving scalp psoriasis specifically. 3
2. PUVA photochemotherapy - more efficacious than NB-UVB for thick lesions and darker skin due to better UVA penetration. 3
3. Methotrexate - effective for severe, recalcitrant, disabling psoriasis not responsive to other therapies (contraindicated with significant alcohol intake or liver disease). 3, 4
4. Acitretin - can be used as monotherapy or combined with NB-UVB, particularly suitable for postmenopausal women (teratogenic, contraindicated in women of childbearing potential). 3
5. Biologic agents (anti-IL-17, anti-IL-23) - for severe cases, though TNF-alfa inhibitors are contraindicated in patients with demyelinating diseases like multiple sclerosis. 3

Critical Safety Warnings

• Never prescribe systemic corticosteroids - they can precipitate erythrodermic or generalized pustular psoriasis upon discontinuation. 2
• Never abruptly stop potent topical corticosteroids - taper gradually to prevent rebound effects. 1, 5
• Tazarotene is pregnancy category X; most other topical psoriasis medications are category C. 1
• Avoid lithium, chloroquine, and mepacrine - associated with severe, potentially fatal psoriasis deterioration. 2

Maintenance Strategy

After achieving clearance:

• Gradually reduce corticosteroid frequency to once daily, then weekend-only application. 1, 2
• Consider alternating between topical corticosteroids and vitamin D3 derivatives with coal tar-containing shampoo for long-term management. 6
• Periods each year should employ alternative treatments to minimize cumulative steroid exposure. 5