fingernail indentation/hepatitis

My 9 year old child recently was diagnosed with unspecified hepatitis (negative for A,B,C) 3 months ago(symptoms began with fever and stiff neck with an itchy rash(hive-like to lower legs), then nausea with abdominal pain, sore throat, and total body itchy rash(hive-like),he then had dark, foamy urine and slightly yellow tinged eyes.  This lasted for approximately 3 months, after his whole body skin peeled and "itchiness" subsided. Now, for the past two weeks I have noticed that he now has severe indentations to all his fingernails/toenails and began with a minimal "itchy" rash to the trunk of his body without any of the other symptoms.  My question is......could the fingernail/toenail indentation be a delayed side effect/related to the hepatitis? and how does this exactly create the indentation, if they are related?