DX for 80074

We have a patient with Grovers Disease and acute pruritis. She was sent for acute hepatitis panel (80074) with diagnosis 698.9 which lab is saying medicare will deny due to medical necessity. She was sent for hepatitis panel to rule our hepatitis as it can be a cause of pruritis. Can anyone tell me what diagnosis should be used to get this covered? I briefly scanned through Medicare site but did not find anything helpful. Thanks in advance, Debi