"Interface dermatitis" is a histological feature of
Psoriasis
Lichen planus
Pityriasis rosea
Dermatophytosis
Interface dermatitis includes diseases in which the primary pathology involves the dermo-epidermal junction. (hence called interface). The salient histological findings include basal cell vacuolization, apoptotic keratinocytes (colloid or Civatte bodies), and obscuring of the dermo-epidermal junction by inflammatory cells. Lupus erythematosus, dermatomyositis, lichen planus, graft versus host disease, erythema multiforme, fixed drug eruptions are some examples. Ref Harrison 20th edition pg 1234
Papulosquamous disorders