<prompt> Etiology of Pityriasis rosea is: March 2012M. furfurHerpes virusAutoimmuneStaphylococcus  <response>: Ans: B i.e. Herpes virus Skin conditions and causative agent Etiological factor for pityriasis versicolor is Malassezia furfur earlier classified as pityrosporum ovale, a commonest yeast Etiology of pityriasis rosea is unkown. A virus Human herpes Virus-7 more frequently, HHV-6 less frequently has often been incriminated Pemphigus vulgaris is an autoimmune disease, characterized by acantholysis, induced by deposition of IgG autoantibodies in an intercellular area of epidermis Staphylococcus aureus, present in either a distant cutaneous focus or in an extracutaneous focus releases an exfoliative toxin that results in peeling of skin staphylococcal scalded skin syndrome. 