<prompt> In measles, when do the Kopliks spots appear?On the day that fever occursOn the day that rashes appear1 -3 days before the rashes appear1-2 days before the fever occurs  <response>: In measles ,a prodromal illness,1-3 days before the rash,occurs ,with upper respiratory symptoms ,conjunctivitis , the presence of the pathognomonic Kopliks spots,small white spots surrounded by erythema on the buccal mucosa. Reference: Harrison20th edition pg 879 