Differential Diagnosis for Colonic Perforation in a Patient with Acquired Immunodeficiency Syndrome (AIDS)

• Single Most Likely Diagnosis

  • (b) Cytomegalovirus (CMV): CMV is a common cause of colonic disease in immunocompromised patients, particularly those with AIDS. It can lead to colitis, which may progress to perforation due to the weakened immune response.

• Other Likely Diagnoses

  • (a) Clostridium difficile: While more commonly associated with pseudomembranous colitis, especially after antibiotic use, C. difficile can cause severe colitis that may lead to perforation in immunocompromised patients.
  • (e) Escherichia coli: Certain strains of E. coli can cause severe infections in immunocompromised hosts, potentially leading to colonic perforation, although this is less common compared to CMV.

• Do Not Miss Diagnoses

  • (d) Salmonella typhi: Although less common, Salmonella infections can be more severe in immunocompromised patients and may lead to complications such as perforation. Missing this diagnosis could be catastrophic due to the potential for severe systemic infection.
  • (c) Bacteroides: Part of the normal gut flora, Bacteroides can cause intra-abdominal infections, including those leading to perforation, especially in the context of compromised immunity. While not the most likely cause, it's crucial not to miss due to its potential severity.

• Rare Diagnoses

  • Other opportunistic infections (e.g., Mycobacterium avium complex, Histoplasma capsulatum) can also affect the colon in AIDS patients, potentially leading to perforation, but these are less common causes compared to the ones listed above.
  • Lymphoma or Kaposi's sarcoma involving the colon could also lead to perforation, although these would be considered rare causes in the context of colonic perforation in AIDS patients.