What is the best approach to managing a patient with contact dermatitis?

Approach to Contact Dermatitis

The optimal management of contact dermatitis requires immediate identification and complete avoidance of the causative agent (allergen or irritant), combined with patch testing for any chronic or persistent case to distinguish allergic from irritant etiology, followed by topical corticosteroids for acute symptom control and aggressive skin barrier restoration. 1

Initial Clinical Assessment

Essential History Elements

Obtain a detailed exposure history focusing on these specific questions:

• Personal and family atopic history: Document childhood atopic dermatitis, asthma, hay fever, and family history of atopy 1
• Temporal pattern: Identify where symptoms began initially and subsequent spread pattern 1
• Product exposure: Question about cosmetics, personal-care products, topical medications, clothing, bandages, and gloves 1
• Wash products: Document all cleansers, as most contain harsh emulsifiers/surfactants that damage skin barrier in predisposed individuals 1
• Activity relationship: Ask about hairdressing, holidays, home improvements, painting, decorating, recreation, or sports 1
• Occupational factors: Take detailed work history including products handled, review Material Safety Data Sheets, and determine if symptoms improve on weekends/holidays and recur upon return to work 1, 2
• Sunlight exposure: Assess whether symptoms worsen after UV exposure 1
• Irritant contact: Document both wet agents (water, frequency of hand washing) and dry, desiccating products 1, 2

Critical Clinical Principle

Clinical features alone are completely unreliable in distinguishing allergic contact dermatitis from irritant contact dermatitis or atopic/endogenous dermatitis, particularly with hand and facial dermatitis. 1, 3, 2 The pattern and morphology cannot predict cause. 1, 2

Diagnostic Testing Strategy

Patch Testing Indications

Patch testing is the gold-standard investigation and should be performed in: 1

• Any patient with chronic or persistent dermatitis 1, 3
• Atopic/endogenous dermatitis previously well-controlled with topical therapy that becomes difficult or impossible to control with the same treatments 1
• Any case where allergic contact dermatitis is suspected, as diagnosis cannot be made clinically 1, 3

Patch Testing Timing Considerations

Defer patch testing for: 1

• 6 weeks after natural or artificial UV exposure 1
• 3 months after finishing systemic immunosuppressive agents 1
• 6 months after finishing biological agents 1

Important exception: Where immunosuppressive treatment cannot be stopped safely, patch testing can yield positive results which, while possibly suboptimal, may be preferable to not testing at all. 1 Antihistamines do not need to be avoided unless testing for urticaria or contact urticarial reactions. 1

Clinical Assessment Tools

Use objective scoring systems for both initial assessment and treatment response: 1

• Dermatology Life Quality Index (generic tool) 1
• Hand Eczema Severity Index (specific tool) 1
• Investigators Global Assessment for chronic hyperkeratotic hand dermatitis (measures induration, scaling, fissuring) 1

Treatment Algorithm

Step 1: Immediate Allergen/Irritant Avoidance

This is the cornerstone of treatment and must be implemented immediately. 4, 3 Detection and avoidance may require: 1

• Workplace site visits to identify allergen sources and avoidance methods 1
• Contacting manufacturers to determine if allergen is present in products 1
• Identifying suitable substitutes from multiple manufacturers 1

Step 2: Skin Barrier Restoration (Essential for Both Types)

Replace all harsh soaps and detergents with emollients as soap substitutes. 4, 3

For intensive barrier repair, use the "soak and smear" technique: 3

• Soak hands in plain water for 20 minutes 3
• Immediately apply moisturizer to damp skin 3
• Perform nightly for up to 2 weeks 3

Additional moisturization strategies: 3

• Apply moisturizer after every hand washing and before wearing gloves 3
• Use moisturizers in tubes rather than jars to prevent contamination 3

Step 3: Topical Corticosteroid Therapy

For localized acute allergic contact dermatitis: 4, 5

• Apply hydrocortisone 1% to affected area not more than 3 to 4 times daily 6
• For more severe cases, use mid- or high-potency topical steroids such as triamcinolone 0.1% 5
• Apply triamcinolone acetonide cream 0.1% to affected area two to three times daily, rubbing in gently 7

For extensive allergic contact dermatitis (>20% body surface area): 5

• Systemic steroid therapy is often required and offers relief within 12-24 hours 5
• For severe rhus dermatitis, taper oral prednisone over 2-3 weeks to prevent rebound dermatitis from rapid discontinuation 5

Caution for irritant contact dermatitis: Use topical steroids cautiously only if conservative measures fail, as they may damage the skin barrier further with long-term use. 3

Step 4: Second-Line Treatments for Persistent Cases

Consider these options when first-line therapy fails: 4, 3

• Topical tacrolimus where topical steroids are unsuitable or ineffective 4, 3
• PUVA phototherapy for chronic hand eczema 3
• Alitretinoin for severe chronic hand eczema 3
• Systemic immunomodulators for severe, refractory cases 4

Special Considerations for Glove-Related Allergic Contact Dermatitis

Use accelerator-free gloves such as rubber-free neoprene or nitrile gloves. 3 Note that "impervious" gloves have finite permeation time for any substance—a glove may protect for minutes but not prolonged contact (e.g., natural rubber latex gloves and methacrylate bone cement). 1

Prognosis and Long-Term Outcomes

The long-term prognosis for occupational contact dermatitis is often very poor. 1 A Swedish study demonstrated only 25% of 555 patients with occupational contact dermatitis completely healed; one half still had periodic symptoms and one quarter had permanent symptoms. 1 Unfortunately, in 40% who changed occupation, overall prognosis was not improved. 1

For milder cases: Prognosis depends on ease of avoidance—if the patient can avoid the cause, dermatitis will clear. 1 Complete resolution is expected if the causative agent is identified and avoided. 4 Chronic cases may develop if triggers are not identified or eliminated. 4

Allergic contact dermatitis carries worse prognosis than irritant contact dermatitis unless the allergen is identified and avoided. 1 Dermatitis can persist, particularly in those allergic to chromate, epoxy resin, and Compositae after allergen avoidance. 1

Common Pitfalls to Avoid

• Failing to patch test chronic cases: Never rely solely on clinical appearance to distinguish allergic from irritant dermatitis 3, 2
• Continuing allergen/irritant exposure: This prevents healing and is the most common reason for treatment failure 4, 3
• Long-term topical steroid use in irritant contact dermatitis: This damages the skin barrier further 3
• Not considering occupational exposures: These may be transferred to other body areas (including genital area) via hands 4
• Overlooking water as an irritant: Frequent hand washing itself is a significant irritant 2
• Rapid steroid discontinuation: This causes rebound dermatitis in severe cases 5
• Overreliance on barrier creams: These are of questionable value by themselves and may confer false sense of security 1

Workplace Prevention Strategies

After-work creams confer protection against developing irritant contact dermatitis. 1 Controlled clinical trials show benefit in using soap substitutes and after-work creams in reducing incidence and prevalence of contact dermatitis. 1 These should be encouraged and made readily available in the workplace. 1