What is the first line treatment for contact dermatitis?

First-Line Treatment for Contact Dermatitis

The first-line treatment for contact dermatitis is complete identification and avoidance of the causative allergen or irritant, combined with mid-to-high potency topical corticosteroids for acute inflammation and aggressive emollient therapy to restore the skin barrier. 1

Immediate Management Algorithm

Step 1: Allergen/Irritant Identification and Avoidance

• Eliminate all suspected triggers immediately while pursuing definitive diagnosis through patch testing, as this is the cornerstone of treatment and the only path to complete resolution. 2, 1
• Replace all soaps and detergents with emollient soap substitutes, as harsh surfactants cause significant barrier damage in predisposed individuals. 3, 1
• Take a detailed exposure history focusing on: initial symptom location and spread pattern, relationship to specific products (cosmetics, personal care items, topical medications, clothing), occupational exposures, and whether symptoms improve away from work or specific environments. 3, 1

Step 2: Topical Corticosteroid Selection Based on Severity

For localized acute contact dermatitis:

• Apply mid-to-high potency topical corticosteroids such as triamcinolone 0.1% or betamethasone valerate 0.1% to affected areas 3-4 times daily. 1, 4
• For mild cases or sensitive areas (face, genitals), hydrocortisone 1% applied not more than 3-4 times daily is appropriate. 2, 5

For persistent or severe localized disease:

• Escalate to very high potency corticosteroids like clobetasol propionate 0.05% for 2 weeks, which achieves clear or almost clear skin in 67.2% of patients with severe dermatitis. 1, 4

For extensive involvement (>20% body surface area):

• Systemic corticosteroids are required, providing relief within 12-24 hours. 4
• For severe rhus (poison ivy) dermatitis, taper oral prednisone over 2-3 weeks to prevent rebound dermatitis from rapid discontinuation. 4

Step 3: Aggressive Emollient Therapy

• Apply moisturizers immediately after every hand washing using the "soak and smear" technique: soak affected areas in plain water for 20 minutes, then immediately apply moisturizer to damp skin nightly for up to 2 weeks. 1
• Use two fingertip units of moisturizer to hands after each washing. 1
• Select moisturizers packaged in tubes rather than jars to prevent contamination. 1
• For trunk involvement, apply approximately 100g per 2 weeks to restore skin barrier function. 1

Diagnostic Workup During Initial Treatment

Patch testing is the gold-standard investigation and should be pursued for any persistent case or when the causative agent remains unknown, as clinical morphology alone is unreliable in distinguishing irritant from allergic contact dermatitis. 3, 1

Critical Patch Testing Considerations:

• Test to at least an extended standard series of allergens. 1
• Do not apply potent topical steroids to the back within 2 days of testing (causes false negatives). 1
• Keep oral prednisolone ≤10 mg daily if immunosuppression cannot be stopped. 1

Protective Measures During Treatment

• Use appropriate gloves based on exposure type: rubber or PVC gloves with cotton liners for household tasks, neoprene or nitrile for latex allergy. 1, 6
• Apply water-based moisturizer before wearing gloves to prevent occlusive irritation. 6
• Remove gloves regularly to prevent sweat accumulation, which aggravates dermatitis. 1
• Do not over-rely on barrier creams alone—they have questionable value and may create false security. 1, 6

Second-Line Therapies for Refractory Cases

If first-line treatment fails after 2-4 weeks:

• Topical tacrolimus 0.1% is effective where topical steroids are unsuitable, ineffective, or when chronic facial dermatitis raises concerns about steroid-induced skin damage. 1
• Phototherapy (PUVA) is an established second-line treatment for chronic contact dermatitis resistant to topical steroids. 1
• Alitretinoin should be offered for severe chronic hand eczema. 1
• Systemic immunosuppressants (azathioprine, ciclosporin) may be considered for severe, recalcitrant cases. 1

Critical Pitfalls to Avoid

• Never continue using known irritants or allergens—this prevents healing regardless of treatment intensity. 2
• Avoid washing with dish detergent, very hot or very cold water, and disinfectant wipes. 1
• Do not use products containing topical antibiotics without clear indication. 1
• Avoid prolonged occlusion without underlying moisturizer application. 1
• Exercise extreme caution with topical corticosteroids on facial skin—prolonged use causes skin thinning, telangiectasia, perioral dermatitis, and red face syndrome due to increased percutaneous absorption. 1

Prognosis and Follow-Up

• Complete resolution is expected if the causative agent is identified and avoided. 2
• However, prognosis for occupational contact dermatitis is often poor: only 25% achieve complete healing, 50% have periodic symptoms, and 25% have permanent symptoms. 1
• Changing occupation does not improve prognosis in 40% of cases. 1
• Early identification and complete allergen avoidance offers the best chance for resolution. 1