Severe hemophagocytic lymphohistiocytosis secondary to disseminated histoplasmosis in a patient with HIV/AIDS: a case report.

Introduction and importance: Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disorder marked by immune system dysregulation, leading to a severe inflammatory response that can affect multiple organs. It can be triggered by infections, and HLH secondary to disseminated histoplasmosis remains poorly understood, with uncertain guidelines on immunosuppressive therapy. Early diagnosis and prompt treatment are critical in preventing fatal outcomes, but challenges in diagnosis complicate this process, particularly in immunocompromised patients. Case presentation: A 51-year-old immunocompromised woman with asthma, gastritis, and anemia presented with fever, malaise, weight loss, and respiratory symptoms. Initial workup revealed pancytopenia, elevated ferritin levels, and an HIV diagnosis with a low CD4 count. Suspecting HLH, she was treated with antiretrovirals, antifungals, and steroids. Her condition worsened, and she developed MRSA sepsis, metabolic acidosis, and multiorgan failure. Histoplasmosis was confirmed, and treatment with liposomal amphotericin B was initiated. Unfortunately, she suffered a cardiac arrest and died on day 11. Postmortem findings confirmed disseminated histoplasmosis-induced HLH. Clinical discussion: HLH is a rare but severe immune activation disorder causing systemic inflammation, multi-organ failure, and high mortality. It can be primary (genetic) or secondary. Diagnosis follows HLH-2004 criteria, and treatment includes immunosuppressive therapy and hematopoietic cell transplantation. Conclusion: This case illustrates the complexities of diagnosing HLH in immunocompromised patients. Delays in obtaining critical lab results and initiating treatment contributed to the patient's rapid deterioration. Early intervention and careful monitoring are crucial in managing such complex cases, where timely diagnosis can significantly impact patient outcomes.