<prompt> In a patient with a vesicle on shin. Microscopy on Tzank smear showed giant cells. Causative agents is:Vaccinia virusVaricella zosterTuberculousMolluscum contagiosum  <response>: Ans. b Le Varicella zoster Multinucleated giant cells and type a intranculear inclusion bodies may be seen in smears prepared by scraping the base of early vesicles Tzank smears and stained with toludine blue, Giemsa or Papanicolou stain Note: Electron microscopy of vesicle fluid can demonstrate the typical virus 