What is the recommended approach to managing seborrheic dermatitis?

Management of Seborrheic Dermatitis

The most effective approach combines topical antifungal medications (ketoconazole 2% as first-line) to reduce Malassezia yeast with short-term topical anti-inflammatory agents to control inflammation, alongside gentle skin care with mild non-soap cleansers and moisturizers. 1

First-Line Treatment Strategy

Scalp Involvement

• Start with ketoconazole 2% shampoo twice weekly for 2-4 weeks, which achieves an 88% response rate after initial treatment 1
• For scalp application, use shampoos, gels, solutions, or foams rather than ointments or creams, as hair makes traditional formulations messy and difficult to apply 1
• Alternative antifungal shampoos include selenium sulfide 1%, which should be applied twice weekly for two weeks initially, then tapered to weekly or every 2-4 weeks for maintenance 1, 2
• Coal tar preparations (1% strength preferred) can reduce inflammation and scaling in scalp involvement 1

Facial Involvement

• Apply ketoconazole 2% cream once or twice daily to affected facial areas 1
• Absolutely avoid all alcohol-containing preparations on the face, as they significantly worsen dryness and trigger flares 1
• For significant erythema and inflammation, add hydrocortisone 1% cream (low-potency only) for a maximum of 2-4 weeks 1
• Never use medium- or high-potency topical steroids (triamcinolone, mometasone, clobetasol) on facial skin due to unacceptable risk of skin atrophy, telangiectasia, and tachyphylaxis 1

Body Involvement

• Apply ketoconazole 2% cream or other topical antifungals (ciclopirox, clotrimazole) to affected areas on chest, back, and body folds 3, 4
• Low-potency topical corticosteroids may be used short-term alongside antifungals to control inflammation 5

Essential Supportive Skin Care

Cleansing Practices

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

Moisturization

• Apply fragrance-free moisturizers containing petrolatum, mineral oil, urea (≈10%), or glycerin immediately after bathing to damp skin to create a surface lipid film that prevents transepidermal water loss 1
• Reapply moisturizer every 3-4 hours and after each face washing 1
• Use non-greasy formulations, as greasy or occlusive products can promote folliculitis 1

Products to Avoid

• Avoid all alcohol-containing preparations, perfumes, deodorants, and harsh soaps that strip natural skin lipids 1
• Avoid products containing neomycin, bacitracin, or fragrances due to high sensitization rates (13-30% with neomycin) 1
• Avoid topical acne medications (especially retinoids) as they may irritate and worsen the condition 1

Escalation for Inadequate Response

Adding Anti-Inflammatory Therapy

• If ketoconazole alone is insufficient, add clobetasol propionate 0.05% shampoo twice weekly for scalp involvement, which provides superior efficacy compared to ketoconazole alone 1
• For facial involvement when corticosteroids are unsuitable or for prolonged use beyond 4 weeks, consider topical calcineurin inhibitors (tacrolimus or pimecrolimus, off-label) 1, 3

Alternative Topical Agents

• Salicylic acid 0.5-2% lotion applied once daily, gradually increasing to twice or three times daily if tolerated, can be used for scaling 1
• Do not use salicylic acid 6% preparations in children under 2 years, and monitor children under 12 years for salicylate toxicity with prolonged use 1
• Lithium succinate/gluconate preparations may be considered 3

Phototherapy

• Narrowband UVB phototherapy has shown efficacy in open studies and can be considered for recalcitrant cases not responding to topical therapy 1
• Do not apply moisturizers or topical products immediately before phototherapy, as they create a bolus effect 1

Maintenance Therapy

Due to the chronic, relapsing nature of seborrheic dermatitis, maintenance therapy with antifungals is essential. 5

• After initial control with twice-weekly ketoconazole 2% shampoo, taper to once weekly or every 2 weeks for maintenance 1
• Continue gentle skin care practices and moisturization indefinitely 1
• Avoid known triggers (alcohol-containing products, harsh soaps, hot water) 1

Management of Pruritus

• For moderate to severe itching, add oral antihistamines (cetirizine, loratadine, fexofenadina) 1
• Topical polidocanol-containing lotions can provide additional symptomatic relief 1
• Avoid non-sedating antihistamines as monotherapy, as they provide little value in seborrheic dermatitis 1
• Sedative antihistamines can be useful as short-term adjuvants during severe flares with intense pruritus 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 herpes simplex superinfection is suspected 1

When to Refer to Dermatology

Refer to dermatology if: 1

• Diagnostic uncertainty or atypical presentation
• Failure to respond after 4-6 weeks of appropriate first-line ketoconazole 2% treatment
• Recurrent severe flares despite optimal maintenance therapy
• Need for second-line treatments (topical calcineurin inhibitors, systemic therapy)
• Suspected alternative diagnoses (psoriasis, atopic dermatitis, contact dermatitis, cutaneous T-cell lymphoma)

Differential Diagnosis Considerations

Key Distinguishing Features

• Psoriasis: Well-demarcated, indurated plaques with thick silvery scale (not greasy, yellow scales); personal or family history of psoriasis; more sharply defined and thicker lesions 1
• Atopic dermatitis: More intense pruritus and lichenification in chronic cases; flexural involvement more common; personal or family history of atopy 1
• Contact dermatitis: Sharp demarcation corresponding to contact area 1
• Cutaneous T-cell lymphoma: Consider if refractory to standard treatment; look for atypical lymphocytes on biopsy 1

Common Pitfalls to Avoid

• Undertreatment due to fear of corticosteroid side effects: Use appropriate potency for adequate duration, then taper 1
• Prolonged continuous use of topical corticosteroids on the face: Limit to 2-4 weeks maximum due to high risk of skin atrophy, telangiectasia, and tachyphylaxis 1
• Confusing persistent itching after treatment with treatment failure: Mild burning or itching from inflammation can persist for days after yeast is eliminated and does not indicate need for re-treatment 1
• Using greasy products: These can inhibit absorption and promote superinfection 1
• Overuse of non-sedating antihistamines: They have little value in seborrheic dermatitis 1

Pathophysiology Context

Seborrheic dermatitis involves Malassezia species, which metabolize sebum triglycerides into irritating free fatty acids that trigger inflammation, particularly in areas with high sebaceous gland density (scalp, face, chest, back, body folds). 5 This explains why treatment targets both the fungal colonization and the inflammatory response. 5, 6