Quick Shot #6 Answer
Answer: Cytomegalovirus
Cytomegalovirus is a particular concern in this person with both UC and on chemotherapy for breast cancer. CMV colitis can mimic a UC flare, and the presence of a flare can increase susceptibility to CMV colitis. While C. difficile often does cause pseudomembranes in patients with IBD, this was already excluded by negative stool test. Cryptosporidium parvum is an opportunistic infection that can cause diarrhea but is better evaluated for by stool test than biopsy. EBV typically does not cause colitis. While she is immunocompromised, her degree of immunosuppression is likely not severe enough to develop Mycobacterium avium, and therefore CMV is a more likely opportunistic pathogen.
- Lee HS, Park SH, Kim SH, Kim J, Choi J, Lee HJ, Kim WS, Lee JM, Kwak MS, Hwang SW, Yang DH, Kim KJ, Ye BD, Byeon JS, Myung SJ, Yoon YS, Yu CS, Kim JH, Yang SK. Risk Factors and Clinical Outcomes Associated with Cytomegalovirus Colitis in Patients with Acute Severe Ulcerative Colitis. Inflamm Bowel Dis. 2016 Apr;22(4):912-8. doi: 10.1097/MIB.0000000000000675. PMID: 26829410.
- Suzuki H, Kato J, Kuriyama M, Hiraoka S, Kuwaki K, Yamamoto K. Specific endoscopic features of ulcerative colitis complicated by cytomegalovirus infection. World J Gastroenterol. 2010 Mar 14;16(10):1245-51. doi: 10.3748/wjg.v16.i10.1245. PMID: 20222169; PMCID: PMC2839178.
- Yerushalmy-Feler A, Padlipsky J, Cohen S. Diagnosis and Management of CMV Colitis. Curr Infect Dis Rep. 2019 Feb 15;21(2):5. doi: 10.1007/s11908-019-0664-y. PMID: 30771028.