Case of the Month

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Lt. Stefan C. Hamelin, PA-C, MPAS

Stefan Hamelin is a third-year medical student attending the Uniformed Services University of Health Sciences in Bethesda, Maryland. He has indicated no relationships to disclose relating to the content of this article.

Erich Fogg, PA-C, MMSc, department editor

CASE

The patient is a 63-year-old woman who arrived at the emergency department complaining of a 5-day history of diarrhea and increasing abdominal pain. When her symptoms began, she was having approximately four episodes of diarrhea a day. She was now having one episode every hour. She denied any blood, pus, or mucus with the diarrhea, and she did not have foul-smelling, greasy, or floating stools. On the third day of her illness, she began to have progressively worsening abdominal pain. The patient described the pain as constant and sharp, nonradiating, and primarily in her left lower quadrant. She had no fever, nausea, vomiting, or history of recurrent bowel disease. She had not traveled or taken any new medications recently. Her medical history was significant for severe chronic obstructive pulmonary disease (COPD) and heart failure (HF) secondary to rheumatic heart disease. She recently received endocarditis prophylaxis with levofloxacin for a dental procedure.

PHYSICAL EXAMINATION The patient appeared tired. Her vital signs were normal, except for a mildly elevated temperature at 100.1¼F (38.4¼C). No abnormalities were detected on heart and lung examination. Her abdomen was soft without distention, and she had normal bowel sounds. The abdomen was tender to palpation, primarily in the left lower quadrant, but there were no signs of peritoneal irritation. Fecal occult blood test results were negative. No rash was present. Preliminary laboratory results showed a WBC count of 27.3/10 mm³ with a left shift. Stool studies were pending.

WHAT IS YOUR DIAGNOSIS?

Ischemic colitis
Diverticulitis
Pseudomembranous colitis
Inflammatory bowel disease

DISCUSSION

The patient was admitted for IV hydration and medical evaluation. She was given ciprofloxacin and metronidazole for a suspected infectious diarrhea. The next day, the result of testing for Clostridium difficile antigen was positive; oral vancomycin and cholestyramine were added. Despite the aggressive therapy, the patient’s condition continued to deteriorate. An emergency total abdominal colectomy for toxic colitis was performed. Intraoperative examination of the gross pathology showed the pathognomonic pseudomembrane seen with this disease (see Figure 1).

The postoperative course was initially promising. Shortly after surgery, the patient was alert and interactive; and the WBC count, renal function, and vital signs all returned to baseline within 1 week. However, her severe COPD and HF caused the patient to deteriorate clinically. Pneumonia developed, which led to respiratory distress, requiring intubation. The family decided to withdraw care, and the patient succumbed to her illness shortly thereafter.

COMMENT C difficile is a gram-positive, spore-forming rod that causes pseudomembranous colitis. Previously believed to be a commensal organism, it is now known that less than 3% of adults are asymptomatic carriers.¹ The major risk factors for developing pseudomembranous colitis include advanced age, hospitalization, and antibiotic use.² Antibiotic-related alterations of the intestinal flora allow C difficile to flourish. Even a single dose can be enough to cause the disease, and symptoms can appear up to 2 months after antibiotic use.³ The bacteria releases exotoxins A and B, which cause symptoms ranging from a mild, self-limited diarrhea to toxic megacolon. The most common CT finding is a dramatic colonic wall thickening; other possible CT findings include ascites, an “accordion” appearance to the bowel, and pericolic stranding.⁴

Pseudomembranous colitis treatment is based on disease severity. Mild symptoms can be treated with adequate fluid replacement. For more symptomatic disease, oral metronidazole is the first-line treatment. IV administration is less effective and should be avoided, if possible. For severe or unresponsive disease, oral vancomycin and cholestyramine are the appropriate additional medications. Infection control is extremely important when managing patients with C difficile colitis. Contact precautions should be used, and a strict handwashing policy should be enforced to minimize nosocomial spread.⁵

REFERENCES

	1.	Schroeder MS. Clostridium difficile-associated diarrhea. Am Fam Physician. 2005;71(5):921-928.
	2.	Bartlett JG. Clinical practice. Antibiotic-associated diarrhea. N Engl J Med. 2002;346(5):334-339.
	3.	Fekety R. Guidelines for the diagnosis and management of Clostridium difficile-associated diarrhea and colitis. American College of Gastroenterology, Practice Parameters Committee. Am J Gastroenterol. 1997;92(5):739-750.
	4.	Thoeni RF, Cello JP. CT imaging of colitis. Radiology. 2006; 240(3):623-638.
	5.	Hurley BW, Nguyen CC. The spectrum of pseudomembranous enterocolitis and antibiotic-associated diarrhea. Arch Intern Med. 2002;162(19):2177-2184.