Background
Contact dermatitis includes several subcategories of diseases where there is an inflammatory skin reaction due to direct with a causative agent. Most common, this includes irritant contact dermatitis (80%), allergic contact dermatitis and chemical burns. Contact dermatitis is an important cause of childhood dermatitis, being equally likely in childhood as in adulthood.
Signs and symptoms
On examination, contact dermatitis may have varying morphologies. Features include erythema, blisters (vesicles, bullae), swelling, scale, fissures and lichenification (thickened skin). Secondary changes include crusting due to secondary ooze or infection, and excoriations. Most patients will report itch and burning or stinging pain to the affected area.
Diagnosis
The different forms of contact dermatitis may be distinguished by taking a detailed history:
- Irritant contact dermatitis occurs after recurrent exposure to irritants such as wet wipes, soaps, prolonged contact with soiled nappies. The affected area is usually contained to the area of direct contact, and the intensity of inflammatory change is proportional to the dose or amount of irritant contact.
- Allergic dermatitis may occur if sufficient contact with a sensitising chemical occurs, then re-exposure triggers an unexpected inflammatory reaction. The inflammation may spread beyond the borders of direct contact with the allergen.
- Chemical burns occur after direct contact to a toxic substance – most commonly strong acids and alkalis. In children, the most common cause is from household products such as bleaches, detergents and toilet bowl cleaners.
Management
- Avoid causative agents
- Use soap-free washes
- Short course of topical corticosteroid cream to affected area
- Frequent emollient use until skin barrier function restored
- Consider dermatological opinion for further management
References
Paller, A., Gilchrest, B. A., Katz, S. I., Leffell, D. J., Wolff, K., Goldsmith, L. A. (2012). Fitzpatrick’s Dermatology in General Medicine, Eighth Edition, 2 Volume Set. United States: McGraw-Hill Education.
Oakley, A., 2012. Contact dermatitis – DermNet. [online] Dermnetnz.org. Available at: < https://dermnetnz.org/topics/contact-dermatitis> [Accessed 11 February 2023].