Contact allergic dermatitis, also known as contact hypersensitivity, is a type of skin reaction that occurs when the skin comes into contact with a substance to which an individual is allergic.
Key points:
Allergen Exposure: Contact hypersensitivity is triggered by exposure to specific allergens, known as contact allergens. These allergens can be substances like metals (e.g., nickel), plants (e.g., poison ivy), cosmetics, fragrances, rubber, latex, certain medications, and various chemicals.
Delayed Reaction: Unlike immediate allergic reactions (such as hives or anaphylaxis), contact hypersensitivity reactions have a delayed onset. Symptoms may not appear until 24 to 72 hours after exposure.
Symptoms: Common symptoms include redness, itching, swelling, and the development of a rash or blisters at the site of contact with the allergen.
Patch Testing: Diagnosis of contact hypersensitivity often involves patch testing, where small amounts of potential allergens are applied to the skin on patches.
Treatment: Treatment includes avoiding the allergen that triggers the reaction. Topical corticosteroids may be prescribed to alleviate inflammation and itching. In severe cases, oral antihistamines or other medications may be recommended.
Prevention: Prevention involves identifying and avoiding known allergens. This may require careful reading of product labels and being cautious about exposure to potential allergens in various environments.