This summary discusses adult patients. Allergic contact dermatitis in children is addressed separately.

Allergic contact dermatitis (ACD) is a delayed-type (type IV) hypersensitivity reaction that occurs when allergens activate antigen-specific T cells in a sensitized individual. It typically requires repeated exposures before an allergic response is noted and most commonly occurs 24-48 hours after exposure to the offending agent.

Eyelid involvement in ACD can occur in the setting of topical agents (medications or cosmetics), airborne agents, or innocuous transfer of the culprit agent via the fingertips.

With regard to topically applied agents, ACD reactions to medicated drops have been reported, including latanoprost, dorzolamide, and phenylephrine. ACD has also been reported in response to cosmetic products such as acrylate-containing glue used as an eyelash extension adhesive. Many eye shadow products include metals, which are top-ranking allergens in patients with eyelid dermatitis.

Nickel sulfate and gold are top-ranking allergens in eyelid dermatitis. Accidental transfer may occur when hands are contaminated by prior contact with metal products, including jewelry. Similarly, fragrances can be transferred from the hands to the face. Eyelid dermatitis can also be seen due to allergens in artificial fingernails.

Contact allergens may be airborne, such as from cement dust, sprays, or room fresheners, for example (airborne contact dermatitis). Airborne exposures have also been implicated in occupational ACD, such as airborne spread of rubber accelerators. Airborne exposures can sometimes be associated with respiratory difficulty, as described in cases of airborne ACD reactions to methylisothiazolinone (MI).

Photoallergic contact dermatitis is contact dermatitis to an allergen that is incited by sun exposure. In North America, sunscreens are the most common photoallergen.

Related topic: irritant contact dermatitis