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

Treatment of Scalp Psoriasis

For scalp psoriasis, start with topical corticosteroids (class 1-2 for moderate-severe disease) or the combination of calcipotriene plus betamethasone dipropionate in scalp-appropriate vehicles (solutions, foams, shampoos), as these are first-line treatments with the strongest evidence for efficacy and safety. 1

Initial Treatment Algorithm

Mild to Moderate Scalp Psoriasis

• Use class 3-7 topical corticosteroids applied 1-2 times daily for 2-4 weeks initially 1, 2
• Vehicle selection is critical: solutions, foams, and shampoos dramatically improve adherence compared to creams or ointments 1
• After initial control, transition to twice-weekly "weekend therapy" to prevent relapse while minimizing adverse effects 2

Moderate to Severe Scalp Psoriasis

• Use class 1-2 (high-potency) corticosteroids such as clobetasol propionate 0.05% shampoo or solution 1
• Apply twice daily for optimal control of severe cases 3
• Treatment duration should be up to 4 weeks initially, with longer use (>12 weeks) only under careful physician supervision 1, 2
• Clobetasol propionate shampoo used twice weekly as maintenance extends time to relapse to 141 days versus 30.5 days with vehicle (p<0.0001), with 40.3% of patients remaining relapse-free at 6 months 4

First-Line Combination Therapy Alternative

• Calcipotriene plus betamethasone dipropionate gel or foam is equally effective as first-line treatment 1
• This combination achieves 69-74% clear or almost clear status in long-term studies, significantly better than either agent alone (27% with vehicle) 1
• No serious adverse events including striae or HPA axis suppression observed over 52 weeks of treatment 1
• Apply once daily, which improves compliance compared to twice-daily regimens 5

Critical Application Technique and Tapering

• Apply to clean, slightly damp scalp for better absorption 2
• Never stop abruptly after achieving improvement—this causes rebound flares where disease recurs more severely 2
• Gradually reduce application frequency rather than stopping completely 1, 2
• After 2-4 weeks of daily treatment, transition to intermittent dosing (twice weekly) for maintenance 2, 4

Important Safety Considerations and Monitoring

Adverse Effect Profile

• Most common local effects are burning and stinging sensations 1
• The scalp has lower risk for atrophy compared to facial or intertriginous areas, but prolonged continuous use still carries risks of skin atrophy, telangiectasia, striae, folliculitis, and purpura 1, 2
• Clobetasol propionate has potential to depress plasma cortisol levels in some patients, but HPA axis effects are transient and reversible upon completion of 2-week treatment courses 6

Duration Limits

• Avoid continuous daily use beyond 2-4 weeks without medical supervision 2
• Tachyphylaxis (decreased effectiveness) may occur with prolonged continuous application, supporting the intermittent dosing approach 2
• Reassess after 2 weeks; if condition worsens or does not improve, consider alternative diagnoses or treatment modifications 2

Adjunctive Measures

• Always combine with regular emollients and moisturizers applied at separate times to enhance efficacy and reduce total steroid requirements 2
• Use gentle soap substitutes and aqueous emollients rather than normal soaps, which are less dehydrating 2
• Consider ketoconazole shampoos to reduce scalp irritation as adjunctive therapy 2

Special Considerations

Vitamin D Analogue Monotherapy

• Calcipotriene foam achieves 40.9% clear or almost clear status after 8 weeks 1
• Vitamin D analogues show efficacy at 8 weeks but not at 4 weeks—plan treatment duration accordingly 1
• Apply calcipotriene after phototherapy if using both, as UVA radiation decreases calcipotriene concentration on skin 1

When Topical Therapy Fails

• Consider systemic therapy if topical treatment fails, particularly when there is symptomatic disease or more than minimal impact on quality of life 1
• Scalp psoriasis is considered a "vulnerable area" by the European League Against Rheumatism that may warrant systemic therapy 1
• For extensive disease (>5% BSA), narrowband UVB phototherapy is effective and well-tolerated, though it has limitations in improving scalp psoriasis specifically 7

Common Pitfalls to Avoid

• Undertreatment due to "steroid phobia" is extremely common—appropriate short-term use of medium-to-high potency corticosteroids on the scalp is safe and effective 2
• Poor adherence is common due to inconvenience, time constraints, and frustration with messy formulations—vehicle selection is therefore paramount 1
• For women of childbearing potential, most topical psoriasis medications are pregnancy category C, and tazarotene is category X 1