Case Presentation: A 72-year-old man with a with a history of hypertension, coronary artery disease, and atrial fibrillation on warfarin, not known to have immunosuppressive disease, presented to the ED with a 6 week history of loose, non-bloody bowel movements, intermittent melena associated with urge sensation, incontinence, and tenesmus. He had lost 30 pounds over the preceding few months, despite his good appetite. His physical exam was significant for an obese non-tender abdomen, and hyperactive bowel sounds. His blood tests showed acute kidney injury, hypokalemia, a high INR, and a leukocytosis of 15.3 thousand, 83% Neutrophils. CT abdomen showed a stool-filled recto-sigmoid colon with circumferential wall thickening and surrounding inflammatory stranding, and a mild degree of diffuse colonic dilation suggesting some degree of obstruction. Colonoscopy showed poor preparation, and a non-obstructed megacolon to the hepatic flexure with pseudomembranous colitis in the right colon. Stool Clostridium difficile toxin was negative. Repeat colonoscopy showed severe colitis of the transverse colon, and healthy ascending colon. Biopsies revealed CMV infection by immunoperoxidase staining; CMV was not detected in blood by PCR. The patient was admitted to the hospital for inpatient administration of IV ganciclovir, which he received for ten days with resolution of the diarrhea.
Discussion: It is common for immunosuppressed patients to experience bacterial, fungal, and viral infections, including CMV infection. This case demonstrates the importance of considering CMV infection in immunocompetent patients who present with colitis. The presentation is similar to other enteric infections, and requires specific anti-CMV therapy. As shown in this case, CMV colitis in the immunocompetent patient can be severe enough to cause persistent diarrhea until the patient receives the appropriate antiviral treatment.
Conclusions: CMV infection has been reported as a cause of pseudomembranous colitis, as shown in this case, and should be considered in the differential diagnosis of pseudomembranous colitis.