Pneumocystis jirovecii pneumonia (PJP) is an opportunistic, airborne infection that can lead to life-threatening pneumonia and respiratory failure by targeting T lymphocytes. 1,2 Historically, PJP risk was often associated with patients with human immunodeficiency virus (HIV), malignancies including acute lymphoblastic leukemia (ALL) and Hodgkin's lymphoma, and solid organ or bone marrow transplant. 3 However, inflammatory bowel disease (IBD), including Crohn's disease (CD) or ulcerative colitis (UC), can also increase the risk of PJP. 4 Before the routine use of prophylaxis and antiretroviral therapy, there was a higher prevalence of opportunistic infections (OI) especially among patients with acquired immunodeficiency syndrome. 5 Patients with CD4 T lymphocyte (CD4) counts of less than 200 cells/m 3 or CD4 cell percentage <14% were at higher risks of OI due to significant immunosuppression. 5,6 Studies suggest that mortality from PJP in patients receiving immunomodulators may be higher than in patients with HIV. [7][8][9] A retrospective review evaluated 475 patients who developed PJP (442 HIV patients, 33 non-HIV patients) from 1985 to 1995 at