hemolytic-uremic syndrome

Hemolytic-uremic syndrome is the most common cause of acute kidney failure in young children. It is a systemic disease, involving a triad of symptoms:

It most frequently follows an episode of gastroenteritis caused by an toxin-producing strain of Escherichia coli (E.coli), type O157:H7. It has been less often associated with other infectious agents such as the bacteria Shigella, Salmonella, Campylobacter, and Streptococcus pneumoniae, as well as some viral infections.

The syndrome is most common in children younger than 4 years old. It is usually preceded by gastroenteritis with the usual fever, vomiting, abdominal pain, and diarrhea. The diarrhea is often bloody, which in itself is always a worrisome sign. Less commonly the illness is preceded by an upper respiratory tract infection - a cold. About 5-10 days later the initial illness is followed by the sudden onset of paleness, irritability, weakness, lethargy, and decreased urination. Examination at that time may also show signs of dehydration, swelling (edema), petechiae, and enlargement of the liver and spleen (hepatosplenomegaly).

The disease results when a specific toxin secreted by a bacteria, usually E. coli O157:H7, attacks the lining of the tiniest arteries in the kidneys. These arteries are damaged, and the blood filtering ability of the kidneys is severely reduced. The damaged areas of the arteries are rough, and in turn cause damage and destruction of the red blood cells coursing through them. This causes the hemolytic anemia.

Platelets accumulate in the arteries, clotting and clogging the vessels, and such large numbers of them are used up that the platelet levels in the bloodstream may fall to critical levels. This can result in turn in hemorrhages elsewhere in the body.

Damage to tiny arteries is not restricted to the kidneys, however. Clotting and vessel damage elsewhere in the body can cause nervous system symptoms such as irritability, seizures, stroke, or coma. Other organs may be damaged as well, such as the pancreas (causing diabetes), the bowel (causing intestinal hemorrhage), or even extensive muscle damage (rhabdomyolysis) from extensive vessel damage in the muscles.

Treatment is supportive, especially focusing on kidney dialysis during the acute phase of the illness. Long term followup of the patients is necessary to watch for late kidney complications is needed, but the recovery is usually fairly complete. Reoccurrence of the disease is rare.

Night, Night! Dr. Hull's Common Sense Sleep Solutions© Site Information/Disclaimer