<prompt> Which one of the following is not a lichenoid reaction?Lichenoid contact reactionPemphigusLichenoid drug eruptionLichenoid reaction of graft versus host disease  <response>: Lichenoid reactions represent a family of lesions with different etiologies with a common clinical histological appearance. They include LIchenoid contact reactions, Lichenoid drug eruptions, Lichenoid reaction of graft versus host disease. 