A case of haemophagocytic lymphohistiocytosis secondary to disseminated histoplasmosis in a patient with advanced HIV

Background: Patients with advanced HIV can present with multiple life-threatening pathologies. Disseminated histoplasmosis is an underdiagnosed infection in advanced HIV which can lead to haemophagocytic lymphohistiocytosis (HLH). Case report: A 36-year-old woman originally from Nigeria was admitted with a two-month history of weight loss, fevers and a papular rash. She was diagnosed with advanced HIV with a CD4 count of 5 cells/mm3 and was pancytopaenic. She spiked fevers despite broad-spectrum antimicrobial therapy. Elevated ferritin and triglycerides levels with haemophagocytosis on bone marrow biopsy indicated HLH; she was treated with immunosuppressive therapy. Mycobacterial blood cultures grew Mycobacterium avium-intracellulare (MAI). She also had an Abiotrophia defectiva bacteraemia, Staphylococcus epidermidis line infection and cytomegalovirus viraemia. Despite treatment of her conditions, the patient deteriorated requiring ICU admission. Blood cultures eventually grew Histoplasma capsulatum. Biopsy of the rash showed fungal elements. She was treated for disseminated histoplasmosis (DH) with antifungals and improved. Discussion: Management of patients with advanced HIV who have multiple pathologies and numerous drug therapies relies on effective multi-disciplinary team involvement. Despite early diagnosis of advanced HIV and early consideration for HLH, there was a significant delay in diagnosis of DH, a condition with a high mortality. This delay was due to factors including the initial attribution of pancytopaenia and fever to HLH and MAI infection instead of DH, as well as the slow growth of H. capsulatum in cultures and lack of alternative diagnostics. Conclusion: Awareness of DH as a cause of HLH in the context of advanced HIV is crucial. Early diagnosis and treatment of both HLH and DH in the context of advanced HIV is associated with improved survival.