How Can Infectious Mononucleosis Be Treated?

My son, (23 years old, 6ft, 180 lb, 2 years ago he was much heavier though), got 10 days ago mononucleosis infection with fever, was taking acetaminophen, and was wrongly diagnosed and given amoxiciline (took it for a week); developed serious skin rash, and found with enlarged liver and enzymes in the range of 200. The day before yesterdays testing he played soccer. Question: Is the 200 enzyme level a cause for alarm and seeking hospital or we can expect that it will subside once his infection resolves? Thank you in advance for your opinion!