Photoallergic Contact Dermatitis

Purpose of Review Photoallergic contact dermatitis (PACD) is a delayed-type hypersensitivity reaction to a photoactivated allergen applied to the skin. The purpose of this review is to provide comprehensive information about the mechanism of photoallergic contact dermatitis and to make an outline of its etiopathogenesis, clinical features, and treatment methods. Recent Findings PACD lesions are generally localized in areas which are exposed to light. However, reactions may spread to covered areas of the body. Most prevalent photoallergens are present in sunscreens and NSAIDs. The diagnosis of PACD is based on patient history and a clinical examination and is confirmed by a photopatch test which allows the distinct separation between PACD and allergic contact dermatitis. Although the basic treatment for PACD is in form of avoiding photoallergens, topical corticosteroids, antihistamines, and immunomodulatory drugs can also be used in the treatment. Photoallergic contact dermatitis is a skin condition caused by UV light exposure after contact with photoallergen or uptake of photosensitizer agent. PACD should always be kept in mind in a patient with history of photosensitivity.