“Interface” Dermatoses: Revisited

Abstract

“Interface dermatoses” are defined as inflammatory dermatoses primarily affecting the interface elements along the dermoepidermal junction, resulting in epidermal basal cell damage. This epidermal basal cell damage can be of two forms: vacuolar/hydropic degeneration and filamentous degeneration (resulting in Civatte bodies). This may be associated with a range of secondary epidermal (atrophy to hypertrophy) and dermal changes (varying from simple effacement of the rete ridges to the diffuse dermal fibrosis/sclerosis). With so many variables, “Interface dermatitis” per se is not a diagnosis by itself but simply a reaction pattern, similar to “psoriasiform dermatitis” or “spongiotic dermatitis.” One should never use these terms as the final sign out diagnosis in reports, though in difficult cases one may allude to the reaction pattern and discuss the possible differentials. This article analyzes and discusses in detail, the basic pathogenesis behind the primary/secondary features associated with interface dermatoses and the steps involved in their histopathological evaluation; thorough knowledge of which may help one arrive at a specific diagnosis.