Cytomegalovirus gastrointestinal disease masquerading as inflammatory bowel disease in a patient with occult HIV infection receiving biologics: A case report.

This case describes a 51-year-old male with ankylosing spondylitis and presumed ulcerative colitis who experienced systemic decline, including 40 lb. weight loss and encephalopathy, while receiving etanercept and upadacitinib. Despite presumptive diagnoses, clinical deterioration prompted reassessment, revealing advanced HIV/AIDS (CD4 count 21 cells/µL) and biopsy-confirmed CMV esophagitis. Discontinuation of JAK inhibition and initiation of antiretroviral therapy led to stabilization. This case highlights the dangers of "diagnostic momentum" and emphasizes that opportunistic infections can mimic autoimmune pathology, necessitating rigorous diagnostic objectivity in patients receiving potent immunomodulators.