Aggregatibacter aphrophilus Bacteremia Associated with Systemic Hemangiomatosis in an Elderly Patient with Ulcerative Colitis: A Case Report.

Introduction: Older patients on biologic therapy for inflammatory bowel disease may be at increased risk for opportunistic infections, reflecting both age-related and immunosuppression-related factors. Aggregatibacter aphrophilus, a HACEK organism, is a rare cause of invasive infection that is typically associated with endovascular disease.

Case presentation: We present the case of a 70-year-old male with ulcerative colitis treated with adalimumab who presented with 4 weeks of fevers, chills, night sweats, and weight loss. CT imaging revealed an intraluminal esophageal lesion and multiple hypodense splenic lesions. Endoscopy demonstrated a vascular-appearing esophageal lesion, and MRI revealed diffuse hemangiomatosis involving the esophagus, spleen, and head and neck musculature. Brain MRI demonstrated a lesion consistent with a septic embolus. Blood cultures grew A. aphrophilus. Applying the 2023 Duke-ISCVID criteria, this case fulfills criteria for possible infective endocarditis. The patient was treated with intravenous ceftriaxone for 4 weeks with clinical improvement. Adalimumab was held after discharge, and ulcerative colitis was subsequently managed with mesalamine with achievement of clinical remission.

Conclusion: Clinicians should be vigilant for complications of immunosuppressive therapy for older patients with inflammatory bowel disease and maintain a broad differential for bacteremia, considering uncommon pathogens such as A. aphrophilus. The esophageal hemangioma precluding transesophageal echocardiography in this case illustrates the diagnostic importance of the 2023 Duke-ISCVID criteria and alternative cardiac imaging modalities in the evaluation of suspected native valve endocarditis when standard approaches are anatomically contraindicated.