Symptoms & Diagnosis
What are the Signs and Symptoms of Post Diarrheal Hemolytic Syndrome (D+HUS) and how is the Diagnosis Made?
The bowel inflammation that occurs prior to the onset of HUS is generally referred to as the prodrome. Within a few days after ingesting Stx producing E. coli, the colon becomes severely inflamed, causing diarrhea that soon becomes bloody. A stool specimen obtained at this point is usually positive for E. coli O157:H7 or Shiga toxin. However, in many patients the window for capturing E. coli O157:H7 is narrow.
During the prodromal phase of HUS, the initial diagnosis is often acute surgical abdomen, acute appendicitis, or ulcerative colitis. The large bowel inflammation (colitis) can be mistaken for acute appendicitis because the site of intense inflammation is in the right lower part of the abdomen. If this leads to an appendectomy, the appendix is almost always found to be normal, but the surrounding bowel is swollen and hemorrhagic. If a colonoscopy is conducted, severe inflammation, ulceration and pseudomembranes (comprised of sloughed mucosal cells, white blood cells and fibrin) are found. If computerized tomography (CT) of the abdomen or a barium enema is performed, a thickened and inflamed bowel is found. Following several days of diarrhea, thrombocytopenia (low platelet count), hemolytic anemia and acute renal failure converge to form the trilogy that defines D+ HUS.
What are the Physical Signs and Laboratory Values on Admission to the Hospital?
Physical findings on admission to the hospital may include lethargy, abdominal tenderness, purpura (bruising), swelling, or dehydration, depending on the net fluid balance. Occasionally, patients may be comatose. Features on admission that portend a severe or fatal outcome include coma, rectal prolapse, decreased or absent urine output (oligoanuria), or white blood cell count (WBC) greater than 20 x 109/l (i.e., greater than 20,000).