Interface-dermatitis is defined as a type of cutaneous inflammation in which the dermo-epidermal junction is obscured. It is associated with vacuolar alteration at the dermo-epidermal junction, necrosis of individual keratinocytes, and melanophages in the papillary dermis. Differentiation between the large number of diseases characterized by an interface dermatitis can be accomplished by analysis of the density, localization, and composition of the infiltrate, number and localization of necrotic keratinocytes, and alterations of the epidermis (hyperplastic vs. atrophic). Several methods for a systematic approach to the diagnosis of interface dermatitides have been proposed; an own scheme combining different aspects of those methods is presented.