<prompt> In contact dermatitis which cells play major role-T-cellsB-cellsLanghan cellsMacrophage  <response>: Contact dermatitis is a type IV hypersensitivity reaction. - this is a cell mediated response. The antigen activates specifically sensitised CD4 CD8 T lymphocytes leading to the secretion of lymphokines and phagocyte accumulation. Reference : Anathanarayan panikers 9th edition, pg no: 162 p 