Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content +++ Key Features +++ Essentials of Diagnosis ++ Bloody diarrhea is the usual presenting complaint, followed by hemolysis, thrombocytopenia, and renal failure Circulating toxin causes endothelial damage, which leads to platelet deposition/consumption, and microvascular occlusion with subsequent hemolysis Similar microvascular endothelial activation may also be triggered by Drugs (eg, cyclosporine) Viruses (HIV) Pneumococcal infections Rare cases are caused by genetic factors causing complement dysregulation (eg, factor H deficiency) +++ General Considerations ++ Most common glomerulovascular cause of acute renal failure in childhood Diarrhea-associated form Usually the result of infection with Shiga toxin–producing strains of Shigella or Escherichia coli Ingestion of undercooked ground beef or unpasteurized foods is a common source There are many serotypes, but the most common pathogen in the United States is E coli O157:H7 +++ Clinical Findings ++ HUS due to Shigella or E coli Begins with a prodrome of abdominal pain, diarrhea, and vomiting Oliguria, pallor, and bleeding manifestations (principally gastrointestinal) occur next Pneumococcal-associated HUS typically presents with Documented pneumococcal pneumonia Sepsis Meningitis Atypical HUS associated with complement dysregulation An episode of HUS often develops following intercurrent illness Presents with malaise and pallor Hypertension and seizures develop in some children—especially those in whom severe renal failure and fluid overload develop There may also be significant endothelial involvement in the central nervous system (CNS), heart, and pancreas +++ Diagnosis ++ Anemia may be profound Red blood cell (RBC) fragments are seen on blood smears Thrombocytopenia is often severe, but other coagulation abnormalities are less consistent Serum fibrin split products are often present, but fulminant disseminated intravascular coagulation is rare Hematuria and proteinuria are often present Hemoglobinuria is occasionally observed due to marked RBC hemolysis +++ Treatment ++ Meticulous attention to fluid and electrolyte status is crucial Antimotility agents and antibiotics for HUS caused by gastrointestinal infection should be avoided because antibiotics may cause release of large amounts of Shiga toxin Timely dialysis improves the prognosis RBC transfusions are often necessary Platelet transfusions should be avoided unless there is active bleeding Erythropoietin (epoetin alfa) May reduce RBC transfusion needs Indicated for patients with renal failure Atypical HUS due to complement dysregulation May benefit from plasmapheresis or plasma infusion However, eculizumab has replaced these therapies Plasma therapy should be avoided in pneumococcal HUS because it drives the HUS process by providing the anti–Thomsen-Friedenreich antibody +++ Outcome +++ Follow-Up ++ Includes serial determinations of renal function with frequency dictated by the etiology, course, and subsequent findings and routine monitoring of blood pressure +++ Complications ++ Complications of acute kidney injury occur Neurologic problems, particularly seizures, may result from hyponatremia, hypertension, or CNS vascular disease Despite thrombocytopenia, many children are thrombophilic due to the underlying endothelial damage +++... Your MyAccess profile is currently affiliated with '[InstitutionA]' and is in the process of switching affiliations to '[InstitutionB]'. Please click ‘Continue’ to continue the affiliation switch, otherwise click ‘Cancel’ to cancel signing in. Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Username? Forgot Password? Sign in via OpenAthens Sign in via Shibboleth