Allergic contact dermatitis

•  is an important cause of "eczematous" dermatitis distinct from atopic dermatitis:
•  allergic contact dermatitis: type IV hypersensitivity to an allergen in contact with the
                                                skin (e.g. nickel allergy, poison ivy)
 
     

     


• irritant contact dermatitis: contact of the skin with something that primarily causes
                                                direct local irritation