Hemolytic Uremic Syndrome (HUS)

Illustration of the anatomy of the kidney

What is HUS?

Hemolytic uremic syndrome is a rare condition that primarily affects children under the age of 10. It is often characterized by:

  • Damage to the lining of blood vessel walls

  • Destruction of red blood cells

  • Kidney failure

What causes HUS?

Most cases of HUS occur after an infection in the digestive tract caused by the E. coli bacterium, O157:H7, the most common type in the United States. Diarrhea and upper respiratory infections are the most common precipitating factors in contracting HUS. This type of E. coli can be found in undercooked meat and is one of the causes of restaurant-related food poisoning outbreaks. HUS is less common in adults, but may occur more often in pregnant women, women who have been taking oral contraceptives, and women who are postpartum or having obstetric complications.

How might HUS progress?

The first stage of HUS frequently lasts from one to 15 days and may include gastrointestinal symptoms, such as:

  • Abdominal pain

  • Bloody diarrhea

  • Vomiting

Severe problems in the bowel and colon may develop in some cases. In these cases, even if the gastroenteritis has stopped, a child may still exhibit the following symptoms:

  • Irritability

  • Fatigue

  • Small, unexplained bruises or small, clot-sized hemorrhages visible in the mucosal lining of the mouth

  • Paleness

The child may produce little urine because damaged red blood cells and other factors may clog the tiny blood vessels in the kidneys or cause lesions in the kidneys, making the kidneys work harder to remove wastes and extra fluid from the blood.

The body's inability to rid itself of excess fluid and waste may, in turn, cause:

  • High blood pressure

  • Swelling of the hands and feet

  • Generalized fluid accumulation (edema)

The symptoms of HUS may resemble other conditions or medical problems. Consult a doctor for diagnosis.

What does treatment for HUS commonly involve?

There is no known treatment that can stop the progress of the syndrome once it has started. It is important for your doctor to distinguish this disease from a similar condition called thrombotic thrombocytopenic purpura, which does have a specific treatment.

A treatment regimen for HUS will be established by your doctor based on your individual condition. Most treatments are aimed at easing the immediate symptoms and signs of this disease and at preventing further complications. This may include any or all of the following:

  • Treatment of high blood pressure

  • Maintaining specific levels of fluids and salts

  • Blood transfusions

  • Kidney dialysis

  • Medication

What is the prognosis for for HUS?

Most children with HUS recover fully. A few, however, will have lasting kidney damage.