Wednesday, October 17, 2007


A five year old baby is brought in five days after a severe episode of bloody diarrhea. The labs do not look good. Creatinine is elevated, platelets are low, and the baby is anemic. When you look at the RBC's, you see the image above. On exam, you find no neurologic abnormalities.

Challenge: What is the most likely diagnosis?

Related Questions:
1. What are low platelets called?
2. What is seen on the image?

Image shown under fair use.


Alex said...

1) thrombocytopenia
2) hemolysis

so its hemolytic uremic syndrome, from either E coli 0157 or Shigella. I think O157 is the unique pathogen of the EHEC strains that causes HUS and not just bloody diarrhea because it has Shiga-like toxin. The other thing is that "shigella" is so much like E Coli that if it was discovered today, it might be considered an E Coli.

I bet there is a lab test to figure out which strain specifically, although I don't know if that is clinically necessary. Maybe knowing background on the food, if there was an outbreak, and case context (is this in a developed country like the US) could help say which is more likely. I'd say O157.

Craig said...


The elevated creatinine signifies acute renal failure. The low platelets signify thrombocytopenia. The anemia with damaged RBCs or schistocytes signify microangiopathic hemolytic anemia. In this hemolytic anemia, red blood cells are shredded as they pass through vessels with endothelial damage, fibrin deposition, and platelet aggregation. The causes of microangiopathic hemolytic anemia are aortic stenosis, thrombotic thrombocytopenic purpura, hemolytic uremic syndrome, disseminated intravascular coagulation, HELLP and eclampsia, heparin-induced thrombocytopenia, and other rare causes. Here, the other findings along with lack of neurologic findings increase suspicion for hemolytic uremic syndrome. The diarrhea is mostly caused by E.Coli O157:H7, a strain that produces Shiga/Shiga-like toxin.

Sources: Wikipedia, University of Virginia Pathology website.