Which type of dermatitis is caused by an allergic reaction to specific substances?

Allergic contact dermatitis is characterized by an allergic reaction that occurs when the skin comes into contact with a specific allergen. This type of dermatitis arises from sensitization to a foreign substance, which triggers an immune response upon subsequent exposures. Common allergens include nickel, fragrances, certain preservatives, and poison ivy.

In allergic contact dermatitis, the individual’s immune system identifies the substance as a threat and responds by causing inflammation, redness, itching, and sometimes swelling in the area where the skin has been in contact with the allergen. This distinguishes it from other types of dermatitis, such as irritant dermatitis, which is caused by direct damage to the skin from a chemical or physical agent rather than an immune reaction.

Atopic dermatitis, on the other hand, is associated with a more generalized skin condition often linked to food allergies and asthma, rather than to specific substances. Contact dermatitis is a broader category that includes both irritant and allergic reactions, but allergic contact dermatitis specifies the immune-mediated nature of the response to particular allergens. Thus, allergic contact dermatitis is the correct choice for describing dermatitis caused specifically by an allergic reaction to certain substances.