Allergic contact dermatitis is characterized by inflammation at?

Allergic contact dermatitis is a type of skin inflammation that occurs when the skin comes into direct contact with an allergen, triggering an immune response. This reaction is localized to the area of contact because it requires exposure to the specific allergen to initiate an inflammatory response. The primary manifestation occurs exactly where the allergen was encountered, leading to symptoms such as redness, itching, and swelling confined to that area.

The other options do not accurately describe the nature of allergic contact dermatitis. While inflammation can occur on any area of the body, it is specifically tied to direct exposure to allergens rather than occurring randomly. Additionally, it does not typically occur only on sun-exposed areas or exclusively in regions treated with topical medications, as those factors do not directly cause the immune response associated with allergic contact dermatitis. The defining feature of this condition is the reaction at the exact site of allergen contact.