SHM Converge Scientific Abstract ePoster Gallery-Diagnostic Bias in the Age of Biologics: A Case of CNS Blastomycosis in a Patient With Crohn's Disease on Infiliximab

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A 35-year-old man with Crohn’s disease on infliximab, plus anxiety, depression, and other medications, presented with one month of worsening headaches and behavioral changes. He had multiple prior ED visits, where his symptoms were initially attributed to complex migraine, and he had started amitriptyline as an outpatient. On re-presentation, he had severe headaches with nausea, vomiting, photophobia, phonophobia, and erratic mood and behavior.<br /><br />Initial workup showed normal CTA head/neck, normal MRI brain, and CTV without venous sinus thrombosis but with a flattened pituitary. Ophthalmologic exam demonstrated bilateral grade 2 papilledema. Lumbar puncture revealed markedly elevated opening pressure (42 cm H2O), mild lymphocytic pleocytosis, elevated protein, and normal glucose. Given his BMI, testosterone use, and hypogonadism, he was initially treated as having idiopathic intracranial hypertension (IIH), and acetazolamide led to partial symptom improvement.<br /><br />However, additional testing later returned a strongly positive CSF Blastomyces antibody. Chest CT showed adenopathy and a micronodular pattern consistent with pulmonary blastomycosis. He was treated with amphotericin for 4 weeks, then transitioned to an azole. Further history revealed that he lived near a damp, wooded area, supporting environmental exposure.<br /><br />This case highlights how biologic therapy, especially TNF-alpha inhibition with infliximab, increases risk for opportunistic fungal infection and should prompt a broad differential diagnosis in hospitalized patients. It also illustrates the danger of diagnostic anchoring: initial improvement on treatment for presumed IIH could have delayed recognition of CNS blastomycosis.

Asset Subtitle

Elizabeth A. Glover

Meta Tag

Author List Elizabeth A. Glover

Category Clinical Vignettes

Concept Immunosuppression

Concept Central Nervous System Blastomycosis

Concept Blastomycosis

Concept Infliximab

Concept Differential Diagnosis

Distinguished Non-Finalist

Presenter Organization Vanderbilt University Medical Center

Presenting Author Elizabeth A. Glover

Track Adult

Keywords

Crohn’s disease

infliximab

blastomycosis

intracranial hypertension

papilledema

lumbar puncture

CSF antibody

amphotericin

TNF-alpha inhibitor

opportunistic fungal infection

Immunosuppression

Central Nervous System Blastomycosis

Blastomycosis

Infliximab

Differential Diagnosis