What is Allergic Contact Dermatitis (ACD)?
Allergic contact dermatitis occurs from a person’s immune response to contact allergens, such as fragrances, preservatives, nickel, gold, and many others. Allergic reactions to contact allergens develop hours or days after exposure, and may take weeks to heal. A personal or family history of other allergies may increase a person’s chance of developing this skin condition.
In already sensitized individuals, this immunologic response is elicited by contact with a specific allergen or closely related chemical. Symptoms typically manifest 24 to 72 hours after allergen exposure, vary in intensity and often include itching and vesiculation. More than 3,000 chemicals are reportedly capable of causing allergic contact dermatitis but relatively few allergens account for most cases. These common allergens form the basis of diagnostic patch testing that is used to differentiate allergic from irritant contact dermatitis.
Allergic contact dermatitis is responsible for approximately half of all contact dermatitis cases. Patients with persistent, unresolved contact dermatitis can suffer for years with a diminished quality of life and increased medical treatment costs. However, the condition can be effectively treated once an accurate diagnosis is obtained.