What is the first-line therapy for seborrheic dermatitis?

Treatment of Seborrheic Dermatitis

First-line therapy for seborrheic dermatitis combines topical antifungal agents (ketoconazole 2% cream or shampoo) with short-term low-potency topical corticosteroids for inflammation control. 1, 2

Initial Treatment Approach

For Scalp Involvement

• Apply ketoconazole 2% shampoo as the primary treatment, with an 88% response rate after initial therapy 1
• Use 5 mL applied directly to the scalp skin (not just hair), leave on for 3-5 minutes before rinsing to ensure adequate contact time 2
• For enhanced efficacy with significant inflammation, add clobetasol propionate 0.05% shampoo twice weekly, which provides superior results compared to ketoconazole alone 1
• Alternative antifungal shampoos include selenium sulfide 1%, which has demonstrated efficacy comparable to ketoconazole 1, 3

For Facial and Body Areas

• Apply ketoconazole 2% cream once daily to affected areas for 2-4 weeks until clinical clearing 2
• For significant erythema and inflammation, add hydrocortisone 1% cream (or prednicarbate 0.02% for more severe cases) once to twice daily 1, 2
• Limit corticosteroid use to 2-4 weeks maximum on the face due to high risk of skin atrophy, telangiectasia, and tachyphylaxis 1, 2
• Avoid potent corticosteroids on facial skin entirely 2

Essential Supportive Skin Care

Cleansing Practices

• Use mild, pH-neutral (pH 5) non-soap cleansers or dispersible creams as soap substitutes to preserve natural skin lipids 1
• Apply tepid (not hot) water, as hot water worsens symptoms 1
• Pat skin dry with clean towels rather than rubbing 1

Moisturization

• Apply fragrance-free emollients containing petrolatum or mineral oil immediately after bathing to damp skin 1
• Reapply moisturizer every 3-4 hours and after each face washing 1
• Avoid greasy or occlusive products that can promote folliculitis 1

Critical Avoidances

• Avoid all alcohol-containing preparations on the face, as they significantly worsen dryness and trigger flares 1, 2
• Avoid products containing neomycin (13-30% sensitization rate), bacitracin, or fragrances 1
• Avoid harsh soaps and detergents that strip natural lipids 1, 2

Maintenance Therapy to Prevent Relapse

• Continue ketoconazole 2% shampoo once weekly as prophylactic maintenance, which significantly reduces recurrence rates compared to reactive treatment only 2
• This maintenance approach is critical, as seborrheic dermatitis is a chronic relapsing condition 4

Second-Line Options for Inadequate Response

Topical Calcineurin Inhibitors

• Consider tacrolimus 0.1% ointment for facial involvement when corticosteroids are unsuitable or for prolonged use beyond 4 weeks 1
• Tacrolimus can be used as maintenance therapy (twice weekly for 20 weeks) to prevent exacerbations 5
• This option is particularly valuable for avoiding long-term corticosteroid complications 1

Alternative Topical Agents

• Salicylic acid 0.5-2% lotion can be applied once daily, gradually increasing to twice or three times daily if tolerated 1
• Avoid salicylic acid 6% preparations in children under 2 years, and monitor children under 12 years for salicylate toxicity 1
• Coal tar preparations (1% strength preferred) reduce inflammation and scaling in scalp involvement 1

Systemic Therapy for Severe or Refractory Cases

Oral Antifungals

• Itraconazole 200 mg daily for 1 week, then 200 mg daily for the first 2 days of each month for 2-11 months is the most studied regimen 6, 4
• Itraconazole shows 93.8% clinical improvement at 2 weeks and significantly lower recurrence rates compared to placebo 4
• Terbinafine 250 mg daily for 4-6 weeks (continuous) or 12 days per month for 3 months (intermittent) is an alternative 6
• Fluconazole 50 mg daily for 2 weeks or 200-300 mg weekly for 2-4 weeks can be used 6
• Ketoconazole 200 mg daily for 4 weeks is associated with more relapses compared to other oral antifungals 6

When to Consider Systemic Therapy

• Widespread disease where topical therapy is impractical 7
• Failure to respond after 4-6 weeks of appropriate topical treatment 1
• Severe disease with significant quality of life impact 8

Management of Pruritus

• Apply topical polidocanol-containing lotions for symptomatic relief 1
• Add oral antihistamines (cetirizine, loratadine, fexofenadina) for moderate to severe itching 1
• Short-term sedating antihistamines can be useful during severe flares with intense pruritus 1
• Avoid non-sedating antihistamines as monotherapy, as they provide no benefit in seborrheic dermatitis without urticaria 1

Monitoring for Complications

Secondary Bacterial Infection

• Watch for increased crusting, weeping, or pustules suggesting Staphylococcus aureus infection 1
• Treat with oral flucloxacillin if bacterial superinfection is present 1

Herpes Simplex Superinfection

• Look for grouped vesicles or punched-out erosions 1
• Initiate oral acyclovir immediately if suspected 1

When to Refer to Dermatology

Refer if any of the following occur: 1

• Diagnostic uncertainty or atypical presentation
• Failure to respond after 4-6 weeks of appropriate first-line therapy
• Recurrent severe flares despite optimal maintenance therapy
• Need for second-line systemic treatments
• Suspected alternative diagnoses (psoriasis, atopic dermatitis, contact dermatitis, cutaneous T-cell lymphoma)

Common Pitfalls to Avoid

• Undertreatment due to "steroid phobia" - use appropriate potency for adequate duration, then taper 1
• Confusing persistent mild itching after treatment with treatment failure - mild burning or itching from inflammation can persist for days after yeast elimination 1
• Applying shampoos only to hair rather than ensuring scalp skin contact 2
• Using regular soaps and detergents on affected areas 2
• Prolonged continuous corticosteroid use on the face beyond 2-4 weeks 1
• Overuse of non-sedating antihistamines, which have no value in seborrheic dermatitis 1