What is the best treatment approach for a 31-year-old male patient with a psoriasis flare-up on his head that is unresponsive to Tera-gel (coal tar) shampoo?

Management of Scalp Psoriasis Unresponsive to Coal Tar Shampoo

For a 31-year-old male with scalp psoriasis unresponsive to coal tar shampoo, clobetasol cream applied once daily for 15 days is an appropriate first-line treatment, but should be limited to a maximum of 2 consecutive weeks due to its high potency, with consideration of a vitamin D analog as a steroid-sparing agent for maintenance therapy.

First-Line Treatment Approach

Topical Corticosteroid Therapy

• Clobetasol propionate (ultrahigh-potency class 1) is appropriate for scalp psoriasis that has failed coal tar therapy 1
• Apply once daily for up to 2 weeks as recommended in the FDA labeling 2
• Limit treatment to 2 consecutive weeks due to risk of HPA axis suppression 2
• Avoid occlusive dressings which can substantially increase absorption 3, 2

Limitations and Monitoring

• Monitor for signs of skin atrophy, telangiectasia, and striae 3
• Amounts greater than 50 mL/week should not be used 2
• Tachyphylaxis (decreased response over time) can occur with prolonged use 1

Combination and Maintenance Therapy

Steroid-Sparing Approaches

• After initial control with clobetasol, consider adding or transitioning to:
  • Vitamin D analogues (calcipotriene/calcipotriol) which work synergistically with corticosteroids 3, 1
  • Weekend-only corticosteroid application for maintenance therapy 1
  • Calcipotriene foam or calcipotriene plus betamethasone dipropionate gel for scalp psoriasis 1

Optimizing Formulations

• For scalp psoriasis, solution, foam, or gel formulations are preferred over creams for better penetration and cosmetic acceptability 4
• Shampoo formulations containing corticosteroids (such as clobetasol propionate 0.05% shampoo) may be more convenient for scalp application than creams 5

Alternative Approaches

If Inadequate Response to Clobetasol

• Consider combination therapy with salicylic acid to enhance penetration 3
• Calcineurin inhibitors (tacrolimus, pimecrolimus) may be helpful, particularly for long-term maintenance 3
• Anthralin (dithranol) short-contact therapy (20-30 minutes daily) may be effective for resistant cases 3

Improved Coal Tar Formulations

• If patient is willing to retry coal tar, newer formulations have improved cosmetic acceptability 6
• LCD 15% solution has shown greater efficacy than calcipotriene cream in moderate plaque psoriasis 7

Treatment Algorithm

1. Initial Phase (0-2 weeks): Clobetasol cream applied once daily
2. Transition Phase (weeks 2-4): Decrease clobetasol to weekend-only application, add vitamin D analog on weekdays
3. Maintenance Phase (beyond 4 weeks):
   • Option A: Vitamin D analog with intermittent corticosteroid use
   • Option B: Corticosteroid shampoo formulation for better compliance
   • Option C: Calcineurin inhibitors for steroid-sparing maintenance

Common Pitfalls to Avoid

• Using high-potency corticosteroids continuously for more than 2 weeks 2
• Applying occlusive dressings with clobetasol, which increases absorption and side effects 2
• Neglecting maintenance therapy after initial clearance, leading to quick relapse 1
• Using tea tree oil alone, which has insufficient evidence for psoriasis treatment

Remember that scalp psoriasis is often more resistant to treatment than psoriasis in other locations, requiring careful selection of vehicle formulations and consistent application techniques 4.