Case Presentation: A 70-year-old woman with hypertension and dyslipidemia presented with several days of shortness of breath, anorexia, and confusion. She was afebrile, hypotensive, and hypoxemic to 50% on room air. Examination revealed cyanotic lips, minimal bilateral air movement, and right-sided wheezing. Lab studies showed lymphocytopenia and an LDH of 414 U/L. There were confluent perihilar ground-glass opacities with interlobular septal thickening and dependent consolidations on CT chest. She was admitted to the MICU on non-invasive ventilation and empirically treated for severe community-acquired pneumonia (CAP).By hospital day 4, she remained hypoxemic without symptomatic improvement. Given her lack of response to CAP therapy, further infectious and autoimmune workup was pursued. HIV-1 testing returned positive with a viral load of 417,000 copies/mL and a CD4 count of 33 cells/μL. Pneumocystis PCR from sputum was positive. She was diagnosed with AIDS and severe Pneumocystis jirovecii pneumonia (PJP) and started on antiretroviral therapy (BIC/FTC/TAF), SMX/TMP, and high-dose corticosteroids.Her 27-day hospital course was complicated by severe hyperactive delirium, tremors, hyperkalemia, and AKI, attributed to steroid therapy and treatment-related toxicities. At 2-month follow-up, her HIV-1 viral load was < 20 copies/mL, and her CD4 count had improved to 145 cells/μL.
Discussion: This case highlights the importance of maintaining a broad differential diagnosis in patients with pneumonia-like symptoms who fail to improve with empiric CAP therapy, including evaluation for possible immunocompromise. Lack of clinical response by 48–72 hours should prompt reassessment of the underlying diagnosis, antimicrobial coverage, and patient risk factors. In this patient, persistent hypoxemia and perihilar ground-glass opacities raised concern for PJP or another opportunistic process in the setting of potential immunocompromise.Although she did not report traditional HIV risk factors and was 70 years old, this case underscores a crucial teaching point: age and perceived risk should never preclude HIV testing when clinical suspicion exists. Older adults are disproportionately diagnosed with HIV at the stage of AIDS and have a greater incidence of opportunistic infections, reflecting delayed detection due to clinician under-recognition and low perceived risk.¹ In this patient, further delay in reaching a diagnosis because of these biases would have resulted poorer outcomes.Her case further illustrates the unique challenges of managing PJP in elderly individuals. High-dose corticosteroids, although lifesaving, are associated with substantial toxicity in this population, including delirium, metabolic derangements, and insomnia, all of which were exemplified in this patient.² Anticipatory monitoring and careful balancing of therapeutic benefit versus harm are important therapeutic considerations.
Conclusions: For hospitalized patients unresponsive to CAP therapy, clinicians should pursue additional diagnostic evaluation, including HIV and autoimmune testing, regardless of age or perceived risk. Furthermore, the treatment of severe PJP in elderly patients with significant hypoxemia presents unique clinical challenges due to increased susceptibility to adverse effects from corticosteroids and antimicrobials. Hospitalists must remain vigilant in monitoring for delirium, electrolyte imbalance, and deconditioning to optimize outcomes in this vulnerable population.