<prompt> Reccurent oral ulcers with pain and erythematous halo around them, diagnosis is:Apthus ulcerHerpesChicken poxMeasels  <response>: A i.e. Apthous ulcer Apthous Ulcers Vitamine deficiency Stress are impoant etiological agents Charecterstically presents with reccurent painful oral ulcers with erythema halo around itQ. 