Contact dermatitis: evaluation and treatment

Contact dermatitis is a common condition that can be categorized as irritant dermatitis and allergic contact dermatitis. Although each of these conditions may have a similar presentation, allergic contact dermatitis is immunologically mediated, whereas irritant contact dermatitis is not. Contact dermatitis can be acute, subacute, or chronic, and each of these phases may progress into the next. Almost any substance may induce a cutaneous reaction, depending on its concentration, the duration of contact, and the condition of the contacted skin. It is estimated that there are more than 6 million chemicals in the environment; approximately 3000 are potential sensitizers. A careful history may identify the responsible agent. If the contactant is identified and eliminated, the contact dermatitis can be a self-limited, mild condition. If the exposure is not discontinued, a cycle of itching, scratching, and skin disruption occurs, which leads to chronic changes in the skin. The history of presentation, including occupational exposures, and distribution of the rash are important in identifying the offending agent. More severe cases may require more extensive evaluation, possibly including patch testing, to determine the offending agent. This article reviews treatment, including antihistamines, topical and oral steroids, physical measures such as cold water compresses, and the treatment of secondary infection.