SHM Converge Scientific Abstract ePoster Gallery-Fever of Unknown Origin: Azathioprine Induced Roseomonas Mucosa Bacteremia

Pdf Summary

This case report describes a 69-year-old man with ulcerative colitis who developed fever of unknown origin, pancytopenia, and bacteremia after his azathioprine dose was increased from 50 mg to 100 mg daily. He presented with shortness of breath, chest pain, anemia, thrombocytopenia, and leukopenia. During hospitalization, he remained hypotensive and febrile despite broad-spectrum antibiotics, requiring blood transfusions and IV fluids.  <br /><br />Blood cultures drawn on admission later grew gram-negative rods, identified on day 5 as Roseomonas mucosa, a slow-growing, pink-pigmented, opportunistic gram-negative bacterium that typically affects immunocompromised patients. His azathioprine was stopped, and the elevated 6-thioguanine nucleotide level suggested prior myelotoxic exposure causing immunosuppression. Extensive workup for fever of unknown origin, including CT scans, PET/CT, and echocardiography, was unrevealing.  <br /><br />Although initial blood cultures cleared, the patient continued to have fevers. Because Roseomonas mucosa often shows resistance to many common antibiotics and susceptibility testing was limited by lack of standardized guidelines, he was treated with intravenous levofloxacin. His fever resolved completely after levofloxacin, supporting R. mucosa as the true cause of the persistent fever. He was discharged to complete a 2-week antibiotic course with piperacillin-tazobactam and oral levofloxacin.  <br /><br />The report highlights that azathioprine-induced pancytopenia can predispose patients to uncommon infections such as R. mucosa bacteremia. It also emphasizes that this organism may present as fever of unknown origin and can be resistant to multiple antibiotics, making careful antibiotic selection important.

Asset Subtitle

Zonghao Pan

Meta Tag

Author List Latasha Naidu, Zonghao Pan

Category Clinical Vignettes

Concept Azathioprine-Induced Pancytopenia

Concept Roseomonas mucosa

Concept Immunocompromised State

Concept Bacteremia

Concept Blood Culture

Distinguished Non-Finalist

Presenter Organization Conemaugh Memorial Medical Center

Presenting Author Zonghao Pan

Track Adult

Keywords

ulcerative colitis

azathioprine

pancytopenia

bacteremia

Roseomonas mucosa

fever of unknown origin

immunocompromised

gram-negative rods

levofloxacin

opportunistic infection

Azathioprine-Induced Pancytopenia

Roseomonas mucosa

Immunocompromised State

Bacteremia

Blood Culture