Here’s an expert-related holding from Campbell v. Autenrieb, 2018 IL App (5th) 170148: Prior to admission, a defendant must establish the relevance of a plaintiff’s prior medical condition through expert witness testimony.This requirement is excused only if a trial court determines that a layperson can evaluate the topic without expert assistance.In this case, plaintiff Steven Campbell testified at trial that in early July 2012 he was working for UPS when the defendant’s dog lunged at him and pushed him …