Persistent Ileal Ulcerations in Crohn's Disease Reveal Silent Intestinal Histoplasmosis in an Immunocompetent Host

Abstract

Persistent ileal ulcerations in Crohn's disease (CD) typically suggest refractory inflammation, yet rare fungal infections may coexist silently. We report a 22-year-old immunocompetent man with CD and seronegative spondyloarthritis who achieved clinical remission on ustekinumab but exhibited persistent ileal ulcerations. Repeat biopsies revealed Histoplasma spp . on Periodic Acid–Schiff staining, confirming intestinal histoplasmosis without pulmonary involvement. Dual pathology required continuation of ustekinumab and initiation of itraconazole. This case highlights the importance of considering fungal infections when endoscopic healing fails despite clinical response.