Unknown Illness, possibly West Nile or autoimmune disease

Hello, my friend is in the hospital with an unknown illness, test have shown an elevated liver enzyme (unsure which one). He appeared with a fever for a few days, rashes on his body, black and purple gums/ lesions and lesions down his esophagus. On high doses of anti fungal, anti inflammatory, and anti bacterial. The doctors think it could possible West Nile virus or some sort of infection or possible an auto immune disorder. All test have shown nothing at this point. Looking for any possible ideas.