What is the recommended first‑line topical therapy for seborrheic dermatitis, and how should selenium sulfide be used?

Selenium Sulfide for Seborrheic Dermatitis

For seborrheic dermatitis, selenium sulfide 1% shampoo is an effective first-line topical antifungal agent that should be applied twice weekly for two weeks initially, then tapered to weekly or every 2-4 weeks for maintenance. 1, 2

First-Line Treatment Strategy

The most effective approach combines topical antifungal medications (to reduce Malassezia yeast) with topical anti-inflammatory agents (to control inflammation and itching). 1 Selenium sulfide has demonstrated efficacy alongside ketoconazole 2% and povidone-iodine as a proven antifungal option. 1

Initial Treatment Phase

• Apply selenium sulfide shampoo twice weekly for two weeks to achieve initial control of seborrheic dermatitis. 2
• After the initial two-week period, reduce frequency to weekly, every two weeks, or every 3-4 weeks depending on response. 2
• Never apply more frequently than required to maintain control, as overuse provides no additional benefit. 2

Scalp Application

• For scalp involvement, use shampoo, gel, solution, or foam formulations rather than ointments or creams, as hair makes traditional formulations messy and difficult to use. 1
• Recent evidence shows a 1% selenium disulfide combined with 0.9% salicylic acid shampoo used three times weekly for 4 weeks reduced severe dandruff from 28.4% to 3.2%, with 90.5% of participants reporting only mild or no dandruff. 3

Maintenance Therapy

• A once-weekly selenium disulfide-based shampoo regimen significantly reduces time-to-relapse after initial corticosteroid treatment, with only 16.7% relapsing at 8 weeks compared to 54.2% with vehicle. 4
• The median time-to-first-relapse was 56 days with vehicle but was not reached with selenium disulfide maintenance. 4

Combination with Anti-Inflammatory Agents

For significant erythema and inflammation, add a low-potency topical corticosteroid (hydrocortisone 1% cream) to affected areas. 1

• Limit corticosteroid use to 2-4 weeks maximum, especially on the face, due to risks of skin atrophy, telangiectasia, and tachyphylaxis. 1
• Never use medium- or high-potency steroids (triamcinolone, clobetasol, mometasone) on facial skin due to unacceptable adverse effects. 1

Essential Supportive Skin Care

• Use mild, pH-neutral (pH 5) non-soap cleansers or dispersible creams as soap substitutes to preserve natural skin lipids. 1
• Apply fragrance-free, non-greasy moisturizers containing urea (≈10%) or glycerin to damp skin after bathing to restore barrier function. 1
• Avoid all alcohol-containing preparations on the face, as they markedly worsen dryness and precipitate disease flares. 1
• Avoid harsh soaps, perfumes, deodorants, and greasy or occlusive products that can promote folliculitis. 1

Alternative First-Line Options

If selenium sulfide is unavailable or not tolerated, ketoconazole 2% is the preferred alternative with an 88% response rate after initial treatment. 1 For ketoconazole cream, apply twice daily for four weeks or until clinical clearing. 5

When to Refer to Dermatology

Refer if: 1

• Diagnostic uncertainty or atypical presentation exists
• Failure to respond after 4 weeks of appropriate first-line therapy
• Recurrent severe flares despite optimal maintenance therapy
• Need for second-line treatments (topical calcineurin inhibitors, phototherapy)

Common Pitfalls to Avoid

• Undertreatment due to fear of side effects: Use appropriate potency corticosteroids for adequate duration, then taper properly. 1
• Overuse of selenium sulfide: Applying more frequently than needed provides no benefit and may increase irritation. 2
• Missing secondary bacterial infection: Watch for crusting, weeping, or pustules suggesting Staphylococcus aureus, which requires oral flucloxacillin. 1
• Confusing persistent mild itching with treatment failure: Mild burning or itching from inflammation can persist for days after yeast elimination. 1