Thrombotic thrombocytopenic purpura and its look-alikes.

The thrombotic thrombocytopenic purpura syndrome (TTP) can be mistaken for a number of other conditions, and it is important to diagnose correctly and treat appropriately. We describe the features of TTP that can help make a positive diagnosis and other conditions in the differential diagnosis with symptoms that can overlap and mimic those of TTR. We discuss TTP and its variants, hemolytic uremic syndrome, disseminated intravascular coagulation, heparin-induced thrombocytopenia, antiphospholipid syndrome, Evans syndrome, preeclampsia/eclampsia, HELLP syndrome, acute fatty liver of pregnancy, and multiorgan failure.