Haemophagocytic lymphohistiocytosis (HLH) secondary to disseminated histoplasmosis infection in a patient with HIV

A male in his 30s who was recently diagnosed with HIV arrived at the emergency department exhibiting an altered mental state and acute respiratory distress. Initial laboratory tests revealed a high anion gap metabolic acidosis, elevated liver enzyme levels and bicytopenia. A CT scan identified a miliary pattern. Bronchoscopy with bronchoalveolar lavage displayed epithelial and inflammatory cells. However, subsequent tests ruled out the presence of fungi, Pneumocystis organisms, malignancies, granulomas and viral inclusions. Broad-spectrum antibiotics with emphasis on Mycobacterium tuberculosis and antifungal treatments were administered. The regimen was adjusted after a positive urine test for the Histoplasma antigen. The patient later manifested signs and symptoms, including increased ferritin level, fever, splenomegaly, diminished natural killer cell function and heightened interleukin-2 receptor levels, confirming haemophagocytic lymphohistiocytosis. Given the patient's gravely decompensated state, the treatment incorporated dexamethasone, and the patient's vasopressor-resistant septic shock was addressed with methylene blue.