Review Question - QID 214221

This patient with a history of IV drug use is presenting with chronic bloody diarrhea, low grade fever, weight loss, and retinitis. These findings are most consistent with cytomegalovirus infection in the setting of an immunocompromised state (most likely HIV given IV drug use, lack of healthcare, and temporal wasting).

Cytomegalovirus (CMV) colitis most often presents in immunocompromised patients with a CD4+ count < 50 cells/mL. Other risk factors include post-transplantation status and chronic high dose steroid use. Additional severe manifestations of CMV infection in immunocompromised patients include CMV pneumonia, CMV esophagitis (linear ulcers), CMV encephalitis (impaired cognitive function and neurological deficits), and CMV retinitis (floaters, photopsia and visual field defects). CMV infection is diagnosed with serological tests (IgM and IgG antibodies), PCR to detect CMV DNA in bodily fluids, and colonoscopy with biopsy. Treatment for severe CMV colitis and retinitis includes ganciclovir or foscarnet.

Figure/Illustration A demonstrates CMV retinitis resulting in retinal hemorrhages and whitening (black circle). CMV retinitis occurs in patients with CD4+ count < 50 cells/mL and results in retinal inflammation causing blurred vision and blind spots that can lead to blindness.

Incorrect Answers:
Answer 2: Colon cancer may present with bloody stools and weight loss; however, retinitis is not a finding associated with colon cancer. Colon cancer is more likely to present with smaller caliber stools (rather than diarrhea) as the mass begins to obstruct the colonic lumen.

Answer 3: Entamoeba histolytica can cause bloody diarrhea, and transmission occurs via the fecal-oral route when traveling in an endemic region. However, E. histolytica is associated with liver abscesses (not retinal pathology) and is treated with metronidazole.

Answer 4: Ulcerative colitis is an inflammatory bowel disease associated with chronic colon mucosal damage resulting in bloody diarrhea, abdominal pain, and fever. Peak incidence is in 15-35-year-old patients. Extraintestinal symptoms include ankylosing spondylitis, primary sclerosing cholangitis, erythema nodosum, and uveitis (not retinitis).

Answer 5: Yersinia enterocolitica is a bacteria that primarily infects the gastrointestinal tract and is acquired from insufficiently cooked pork or contaminated water. Y. enterocolitica causes mild self-limited enterocolitis in immunocompetent patients. In immunocompromised patients, Y. enterocolitica can cause liver and spleen abscesses, and treatment includes doxycycline in combination with an aminoglycoside.

Bullet Summary:
Cytomegalovirus infection in immunocompromised patients may present with colitis and retinitis.