What is your standard diagnostic workup to confirm GVHD in a patient post-BMT with skin rash and jaundice?   

I assume there is no diarrhea, so sigmoidoscopy would not be helpful. Gut and liver pathology are useful. Skin biopsy is less helpful. It can be fairly nonspecific, but we do it to rule out other diagnoses that have more definitive pathology. Ultimately, it is a clinical diagnosis. Liver biopsy woul...

Skin biopsy would be a good start, and I would also consider liver function tests, evaluation of the GI tract, imaging studies, endoscopy, etc.