From the Guidelines
Irritant contact dermatitis is more common than allergic contact dermatitis. According to the British Association of Dermatologists' guidelines for the management of contact dermatitis 2017 1, irritant contact dermatitis is more common than allergic contact dermatitis, although allergic contact dermatitis carries a worse prognosis unless the allergen is identified and avoided. The key differences between irritant and allergic contact dermatitis lie in their pathophysiology and clinical presentation:
- Irritant contact dermatitis develops through direct damage to the skin from exposure to chemicals, detergents, solvents, or physical irritants, and can affect anyone with sufficient exposure.
- Allergic contact dermatitis requires prior sensitization to an allergen and involves the immune system, specifically a type IV delayed hypersensitivity reaction. Common irritants include soaps, detergents, and solvents, while common allergens include nickel, fragrances, and preservatives. Treatment for both types involves identifying and avoiding the causative agent, using barrier creams for protection, and applying topical corticosteroids like hydrocortisone 1% cream for symptom relief. It's essential to note that while irritant contact dermatitis is more common, allergic contact dermatitis can have a worse prognosis if left untreated or if the allergen is not avoided, as stated in the guidelines 1.
Some key points to consider in the management of contact dermatitis include:
- The point prevalence of dermatitis in the U.K. is estimated to be about 20% 1.
- Hand dermatitis has a point prevalence of 2% and a lifetime risk of developing hand dermatitis of 20% 1.
- Contact dermatitis accounts for 4–7% of dermatological consultations 1.
- Patch testing should be carried out in any patient with a chronic or persistent dermatitis, or atopic/endogenous dermatitis that was previously well controlled with topical therapy and then becomes difficult or impossible to control with the same topical treatments 1.
In terms of morbidity, mortality, and quality of life, early diagnosis and treatment of contact dermatitis are crucial to prevent chronicity and improve outcomes. By identifying and avoiding the causative agent, using barrier creams for protection, and applying topical corticosteroids, patients can experience significant improvement in their symptoms and quality of life. It's also important to note that occupational dermatitis remains a burden for those affected, and prevention and early intervention are key to reducing the impact of contact dermatitis on daily life.
From the Research
Comparison of Irritant and Allergic Contact Dermatitis
- Irritant contact dermatitis (ICD) is more common than allergic contact dermatitis (ACD) in both occupational and nonoccupational settings 2, 3.
- ICD has a worse prognosis than ACD 3.
- The most common causes of ICD include cumulative effects of water, soaps, and detergents, while ACD is often caused by substances such as nickel, fragrances, and rubber accelerators 2, 3, 4.
Diagnosis and Management
- Accurate diagnosis and identification of the trigger are crucial for effective treatment of contact dermatitis 5, 4, 6.
- Patch testing is often required for definitive diagnosis, especially when the diagnosis or specific allergen remains unknown 2, 3, 4, 6.
- Treatment relies on avoidance of irritants or allergens, gentle skin care, and prescription topical or systemic therapies or phototherapy when indicated 2, 5, 4, 6.