What first‑line topical treatment options are appropriate for a 28‑year‑old woman with mild plaque‑type psoriasis involving the scalp and posterior neck, who has a family history of psoriasis and Hashimoto thyroiditis, in a primary‑care setting?

First-Line Treatment for Scalp and Neck Psoriasis in Primary Care

Start with a combination product containing calcipotriene 0.005% plus betamethasone dipropionate 0.064% in a foam or gel formulation, applied once daily for up to 4 weeks, as this achieves the highest efficacy (69-74% clear or almost clear status) with excellent safety and is specifically designed for scalp application. 1

Initial Treatment Regimen

Preferred First-Line Option: Combination Therapy

• Calcipotriene/betamethasone dipropionate foam or gel is the optimal starting treatment because it combines a vitamin D analogue with a potent corticosteroid, providing superior efficacy compared to either agent alone while reducing the risk of corticosteroid-related adverse effects 1, 2
• Apply once daily to affected scalp and neck areas for 4 weeks initially 1
• This combination achieved 69-74% clear or almost clear status in a 52-week study with no serious adverse events, including no striae or hypothalamic-pituitary-adrenal axis suppression 1
• The foam or gel vehicle is critical for scalp application—these formulations improve adherence compared to creams or ointments, which patients find messy and inconvenient 1

Alternative First-Line Option: High-Potency Corticosteroid Monotherapy

• If combination therapy is unavailable, use a Class 1-2 (high-potency) topical corticosteroid in solution or foam formulation 1
• Clobetasol propionate 0.05% solution is the most effective monotherapy option, achieving 58-92% efficacy within 2 weeks 1
• Apply once or twice daily for a maximum of 4 weeks without supervision 1
• Do not exceed 50 grams per week to avoid systemic absorption 3, 4

Treatment Duration and Tapering Strategy

Initial Phase (Weeks 1-4)

• Apply the combination product (calcipotriene/betamethasone) twice daily until clinical control is achieved 1
• Most patients show significant improvement within 2-4 weeks 1, 2

Maintenance Phase (After Week 4)

• Taper the corticosteroid component to weekend-only use while continuing the vitamin D analogue (calcipotriene) five days per week 1
• This steroid-sparing approach minimizes the risk of cutaneous atrophy while maintaining disease control 1, 4
• Gradual tapering prevents rebound flares that can occur with abrupt discontinuation 1, 3

Critical Safety Considerations

Monitoring and Precautions

• Monitor for local adverse effects including burning, stinging, skin atrophy, striae, folliculitis, and telangiectasia 1
• Never apply high-potency corticosteroids to the face or intertriginous areas due to increased risk of atrophy 1, 4
• For women of childbearing potential, most topical psoriasis medications are pregnancy category C 1
• Given her Hashimoto thyroiditis, be aware that psoriasis is an inflammatory condition with systemic associations, though this does not change topical management 5

Duration Limits

• Do not use Class 1-2 corticosteroids continuously beyond 4 weeks without close physician supervision 1, 3
• Extension up to 12 weeks may be considered under careful monitoring, but only with the combination product or with a clear tapering plan 1

When to Escalate Beyond Topical Therapy

Indications for Referral or Systemic Treatment

• Scalp psoriasis is considered a "vulnerable area" that warrants systemic therapy if topical treatment fails after 4 weeks of appropriate use 1
• Escalate if the patient has symptomatic disease with more than minimal impact on quality of life despite optimal topical management 1
• Consider referral to dermatology for phototherapy (narrowband UVB) or systemic agents (methotrexate, biologics) if topicals are insufficient 1, 6

Common Pitfalls to Avoid

• Do not prescribe creams or ointments for scalp psoriasis—patients will not adhere to these messy formulations 1
• Do not use corticosteroid monotherapy long-term without a tapering plan—this increases the risk of atrophy and rebound 1, 3
• Do not abruptly discontinue potent corticosteroids—taper gradually to prevent disease flare 1, 3
• Do not allow unsupervised repeat prescriptions of potent corticosteroids beyond 4 weeks 3
• If using calcipotriene, instruct the patient to apply it after any phototherapy (if prescribed later), as UVA radiation can inactivate the medication 1