Pediatric Hemolytic Uremic Syndrome Clinical Presentation
- Author: Robert S Gillespie, MD, MPH; Chief Editor: Craig B Langman, MD more...
History
Patients with diarrhea-associated hemolytic-uremic syndrome (D+ HUS) experience several days of diarrhea, with or without vomiting, followed by sudden onset of symptoms such as irritability and pallor. In more than 80% of patients, the diarrhea is evidently bloody. Other symptoms include restlessness, oliguria, edema, and macroscopic hematuria. In some patients, the prodrome may improve as hemolytic-uremic syndrome symptoms begin. The clinical picture may mimic that of an acute abdomen. In patients infected with a Shiga toxin (Stx)–producing strain of E coli, hemolytic-uremic syndrome occurs in 5-15%. The risk of progression to hemolytic-uremic syndrome is increased in very young or elderly persons, in patients who have been treated with antimotility drugs or antibiotics, and in patients with a fever or a high leukocyte count.
The history should include inquiry about possible recent exposure to E coli, such as consuming undercooked meat, encounters with livestock or petting zoos, contacts with other persons with diarrhea, and attendance at daycare or school. However, most cases of D+ hemolytic-uremic syndrome are sporadic, with no clearly identifiable source of infection, even when stool culture yields a toxigenic organism. Outbreaks involving multiple persons more commonly lead to a source.
Non–diarrhea-associated hemolytic-uremic syndrome (D- HUS) may follow a respiratory illness, especially when caused by S pneumoniae.
Features of all forms of hemolytic-uremic syndrome include the following:
- Hematology
- Hemolysis occurs in all patients with hemolytic-uremic syndrome. It can proceed rapidly, resulting in a rapid fall of the hematocrit.
- Platelet counts usually fall below 40,000/mcL. However, the degree of thrombocytopenia does not correlate with the severity of hemolytic-uremic syndrome, and some children can maintain relatively normal kidney function despite severe hematologic abnormalities.
- Many patients have petechiae, purpura, and oozing from venipuncture sites.
- Overt bleeding is less common.
- CNS
- Patients often present with sudden onset of lethargy and irritability.
- Other findings may include ataxia, coma, seizures, cerebral swelling, hemiparesis, and other focal neurologic signs.
- CNS changes may be caused by cerebral ischemia from microthrombi, effects of hypertension, hyponatremia, or uremia.
- D- hemolytic-uremic syndrome tends to be associated with a greater number of neurologic symptoms than D+ hemolytic-uremic syndrome.
- Renal system
- Acute renal insufficiency usually begins with the onset of hemolysis. Although patients have decreased urine output, frequent diffuse watery stools may mask this sign.
- If renal insufficiency is not recognized and treated, hyponatremia, hyperkalemia, severe acidosis, ascites, edema, pulmonary edema, and hypertension ensue.
- GI tract: D+ hemolytic-uremic syndrome is usually preceded by 3-12 days of watery or bloody diarrhea. Vomiting and crampy abdominal pain are also common. Note that diarrhea may improve as the other hemolytic-uremic syndrome symptoms begin (eg, thrombocytopenia, renal insufficiency). Life-threatening complications include intestinal perforation or necrosis. Even without these complications, the colitis of hemolytic-uremic syndrome may cause severe abdominal pain which may persist for several days into the illness.
- Infectious signs: Fever is present in 5-20% of patients. The presence of fever, leukocytosis, or both is a prognostic indicator of the risk of developing more severe hemolytic-uremic syndrome.
- Pancreas: Mild pancreatic involvement is common but can be severe on occasion, with necrosis, pseudocysts, or both, which can leave the patient with insulin-dependent diabetes and, on rare occasion, exocrine dysfunction.
- Cardiovascular: Congestive heart failure may occur.
Physical
- Blood pressure may be elevated unless the patient is volume depleted (eg, from diarrhea.)
- Child appears ill and pale.
- Abdominal pain and tenderness may be present, possibly severe.
- Peripheral edema may be present.
- Petechiae, purpura, or oozing from venipuncture sites may be present.
Causes
The causes of D+ hemolytic-uremic syndrome and D- hemolytic-uremic syndrome differ.
- D+ hemolytic-uremic syndrome
- GI tract infection with Stx–producing E coli (STEC) precedes most cases of typical D+ hemolytic-uremic syndrome. Stx1 is identical to the Stx produced by Shigella dysenteriae. Stx2 has a 55-60% amino acid homology with Stx. They injure the gut and lead to hemorrhagic colitis. Most cases worldwide are associated with STEC 0157:H7 infection. This organism is very resilient; viable bacteria has been reported in environments up to 10 months following initial contamination. Aside from Stx production, this bacteria produces virulence factors that mediate tight adherence to the host cell, facilitating transluminal transport of the toxins into the systemic circulation. Cattle are the major reservoir for human infection. The use of antimotility agents, antidiarrheal agents, and antibiotics has been reported to increase the risk of developing hemolytic-uremic syndrome.
- Other causes of hemolytic-uremic syndrome include infection by the following:
- S dysenteriae (established as an etiologic agent)
- Salmonella typhi (established as an etiologic agent)
- Campylobacter jejuni (established as an etiologic agent)
- Yersinia species
- Pseudomonas species
- Bacteroides species
- Entamoeba histolytica
- Aeromonas hydrophilia
- Organisms of the class Microtatobiotes
- D- hemolytic-uremic syndrome
- Inherited (eg, mutations in the gene for factor H, a complement regulatory protein)
- S pneumoniae (neuraminidase-associated)
- Portillo virus
- Coxsackie virus
- Influenza virus
- Epstein-Barr virus
- Pregnancy: Hemolytic-uremic syndrome or thrombotic thrombocytopenic purpura (TTP) are associated with pregnancy; pre-eclampsia and HELLP syndrome also have features in common and should be part of the differential diagnosis.
- Drugs (eg, chemotherapy, oral contraceptives, cyclosporine, tacrolimus)
- Bone marrow or hematopoietic stem cell transplantation
- Malignancy
- Idiopathic
- Systemic lupus erythematosus (SLE)
- Glomerulonephritis, especially membranoproliferative glomerulonephritis
- Malignant hypertension
Delvaeye M, Noris M, De Vriese A, Esmon CT, Esmon NL, Ferrell G. Thrombomodulin mutations in atypical hemolytic-uremic syndrome. N Engl J Med. Jul 23 2009;361(4):345-57. [Medline].
Ake JA, Jelacic S, Ciol MA, Watkins SL, Murray KF, Christie DL. Relative nephroprotection during Escherichia coli O157:H7 infections: association with intravenous volume expansion. Pediatrics. Jun 2005;115(6):e673-80. [Medline].
Gillespie RS, Seidel K, Symons JM. Effect of fluid overload and dose of replacement fluid on survival in hemofiltration. Pediatr Nephrol. Dec 2004;19(12):1394-9. [Medline].
Foland JA, Fortenberry JD, Warshaw BL, Pettignano R, Merritt RK, Heard ML. Fluid overload before continuous hemofiltration and survival in critically ill children: a retrospective analysis. Crit Care Med. Aug 2004;32(8):1771-6. [Medline].
Maxvold NJ, Smoyer WE, Custer JR, Bunchman TE. Amino acid loss and nitrogen balance in critically ill children with acute renal failure: a prospective comparison between classic hemofiltration and hemofiltration with dialysis. Crit Care Med. Apr 2000;28(4):1161-5. [Medline].
Murphy EJ. Acute pain management pharmacology for the patient with concurrent renal or hepatic disease. Anaesth Intensive Care. Jun 2005;33(3):311-22. [Medline].
Dean M. Opioids in renal failure and dialysis patients. J Pain Symptom Manage. Nov 2004;28(5):497-504. [Medline].
[Guideline] Ariceta G, Besbas N, Johnson S, Karpman D, Landau D, Licht C. Guideline for the investigation and initial therapy of diarrhea-negative hemolytic uremic syndrome. Pediatr Nephrol. Apr 2009;24(4):687-96. [Medline].
[Best Evidence] Michael M, Elliott EJ, Craig JC, Ridley G, Hodson EM. Interventions for hemolytic uremic syndrome and thrombotic thrombocytopenic purpura: a systematic review of randomized controlled trials. Am J Kidney Dis. Feb 2009;53(2):259-72. [Medline].
Nguyen L, Li X, Duvall D, Terrell DR, Vesely SK, George JN. Twice-daily plasma exchange for patients with refractory thrombotic thrombocytopenic purpura: the experience of the Oklahoma Registry, 1989 through 2006. Transfusion. Feb 2008;48(2):349-57. [Medline].
von Baeyer H. Plasmapheresis in thrombotic microangiopathy-associated syndromes: review of outcome data derived from clinical trials and open studies. Ther Apher. Aug 2002;6(4):320-8. [Medline].
Filler G, Radhakrishnan S, Strain L, Hill A, Knoll G, Goodship TH. Challenges in the management of infantile factor H associated hemolytic uremic syndrome. Pediatr Nephrol. Aug 2004;19(8):908-11. [Medline].
Soliris (eculizumab) [package insert]. Cheshire, CT: Alexion Pharmaceutical; 2011. [Full Text].
Loirat C, Babu S, Furman R, Sheerin N, Cohen D, Gaber O, et al. Eculizumab Efficacy and Safety in Patients With Atypical Hemolytic Uremic Syndrome (aHUS) Resistant to Plasma Exchange/Infusion [poster]. Presented at the 16th Congress of European Hematology Association (EHA). 2011;London, UK.
Loirat C, Muus P, Legendre C, Douglas K, Hourmant M, Delmas Y, et al. A Phase II Study of Eculizumab in Patients With Atypical Hemolytic Uremic Syndrome Receiving Chronic Plasma Exchange/Infusion [poster]. Presented at the 16th Congress of European Hematology Association (EHA). 2011;London, UK.
Sellier-Leclerc AL, Fremeaux-Bacchi V, Dragon-Durey MA, et al. Differential impact of complement mutations on clinical characteristics in atypical hemolytic uremic syndrome. J Am Soc Nephrol. Aug 2007;18(8):2392-400. [Medline].
Zimmerhackl LB, Besbas N, Jungraithmayr T, et al. Epidemiology, clinical presentation, and pathophysiology of atypical and recurrent hemolytic uremic syndrome. Semin Thromb Hemost. Mar 2006;32(2):113-20. [Medline].
Saland JM, Ruggenenti P, Remuzzi G. Liver-kidney transplantation to cure atypical hemolytic uremic syndrome. J Am Soc Nephrol. May 2009;20(5):940-9. [Medline].
Saland JM, Shneider BL, Bromberg JS, et al. Successful split liver-kidney transplant for factor H associated hemolytic uremic syndrome. Clin J Am Soc Nephrol. Jan 2009;4(1):201-6. [Medline].
Jalanko H, Peltonen S, Koskinen A, et al. Successful liver-kidney transplantation in two children with aHUS caused by a mutation in complement factor H. Am J Transplant. Jan 2008;8(1):216-21. [Medline].
Saland JM, Emre SH, Shneider BL, et al. Favorable long-term outcome after liver-kidney transplant for recurrent hemolytic uremic syndrome associated with a factor H mutation. Am J Transplant. Aug 2006;6(8):1948-52. [Medline].
Wong CS, Jelacic S, Habeeb RL, Watkins SL, Tarr PI. The risk of the hemolytic-uremic syndrome after antibiotic treatment of Escherichia coli O157:H7 infections. N Engl J Med. Jun 29 2000;342(26):1930-6. [Medline].
Iijima K, Kamioka I, Nozu K. Management of diarrhea-associated hemolytic uremic syndrome in children. Clin Exp Nephrol. Feb 2008;12(1):16-9. [Medline].
Garg AX, Salvadori M, Okell JM, et al. Albuminuria and estimated GFR 5 years after Escherichia coli O157 hemolytic uremic syndrome: an update. Am J Kidney Dis. Mar 2008;51(3):435-44. [Medline].
Blaser MJ. Bacteria and diseases of unknown cause: hemolytic-uremic syndrome. J Infect Dis. Feb 1 2004;189(3):552-5. [Medline].
Brunner K, Bianchetti MG, Neuhaus TJ. Recovery of renal function after long-term dialysis in hemolytic uremic syndrome. Pediatr Nephrol. Feb 2004;19(2):229-31. [Medline].
Kaplan BS, Cleary TG, Obrig TG. Recent advances in understanding the pathogenesis of the hemolytic uremic syndromes. Pediatr Nephrol. May 1990;4(3):276-83. [Medline].
Kaplan BS, Meyers KE, Schulman SL. The pathogenesis and treatment of hemolytic uremic syndrome. J Am Soc Nephrol. Jun 1998;9(6):1126-33. [Medline].
Milford DV, Taylor CM. New insights into the haemolytic uraemic syndromes. Arch Dis Child. Jul 1990;65(7):713-5. [Medline].
Nathan DG, Orkin SH, eds. Nathan and Oski's Hematology of Infancy and Childhood. Vol 1. 5th ed. Harcourt Health Sciences; 1998:531-6.
Pickering LK, Obrig TG, Stapleton FB. Hemolytic-uremic syndrome and enterohemorrhagic Escherichia coli. Pediatr Infect Dis J. Jun 1994;13(6):459-75; quiz 476. [Medline].
Rangel JM, Sparling PH, Crowe C, et al. Epidemiology of Escherichia coli O157:H7 outbreaks, United States, 1982-2002. Emerg Infect Dis. Apr 2005;11(4):603-9. [Medline].
Robson WL, Leung AK, Kaplan BS. Hemolytic-uremic syndrome. Curr Probl Pediatr. Jan 1993;23(1):16-33. [Medline].
Siegler R, Oakes R. Hemolytic uremic syndrome; pathogenesis, treatment, and outcome. Curr Opin Pediatr. Apr 2005;17(2):200-4. [Medline].
Stewart CL, Tina LU. Hemolytic uremic syndrome. Pediatr Rev. Jun 1993;14(6):218-24. [Medline].
Trachtman H, Christen E. Pathogenesis, treatment, and therapeutic trials in hemolytic uremic syndrome. Curr Opin Pediatr. Apr 1999;11(2):162-8. [Medline].
Varade WS. Hemolytic uremic syndrome: reducing the risks. Contemp Pediatr. 2000;17:54-64.

