<prompt> A 16 year old boy presented with asymptomatic, multiple erythamatous annular lesions with a collarette of scales at periph-ery of the lesions present on the trunk. The most likely diagnosis is:Pityriasis versicolorPityriasis albaPityriasis rosaceaPityriasis rubra pilaris  <response>: C i.e. Pityriasis rosea Pityriasis rosea is a self limiting disorderQ of unknown etiology, with a suspected association with Herpes virus 7 and 6Q. It presents with development of usually asymptomatic i.e. no prodromal or constitutional system, sharply well demarcated, larger 2-6 cm, annular oval-round, erythematousQ red to brown lesion ka primaryheraldmother patch mostly located on trunk in children and young adults 10-35 yrs 2. Similar but smaller secondary eruptions appear in crops at interval of usually 2 weeks distributed along lines of cleavage in christmas fir tree appearanceQ. Lesions demonstrate fine cigarette paper collarette of scaleQ just inside the peripheray of plaque. 