While both can cause photosensitivity, dermatomyositis is distinguished by its pathognomonic findings of a heliotrope rash and Gottron papules, which are absent in GVHD.
This is clinically and histologically very similar, but it is distinguished by its temporal relationship to a new medication and resolution upon its withdrawal, unlike the transplant-related onset of GVHD.
While both can have similar features, lupus is distinguished by its specific serologic markers (e.g., anti-dsDNA, anti-Smith) and the absence of a history of allogeneic transplantation.
Sclerotic-type chronic GVHD can be identical to morphea, but it is distinguished by its context, occurring after a bone marrow or stem cell transplant.
While both cause sclerosis, systemic sclerosis is an idiopathic autoimmune disease with specific autoantibodies (e.g., anti-Scl-70, anticentromere) and lacks the transplant history of GVHD.
