Disseminated Histoplasmosis in a Patient With Acquired Immunodeficiency Syndrome: A Case Report and Literature Review

Histoplasmosis is an endemic mycosis in the central and eastern USA, Central and South America, parts of Asia, and Africa. It commonly presents as a pulmonary disease, but can involve multiple organ systems in immunocompromised individuals. In patients with HIV and low CD4 counts, usually <150 cells/μL, it can present with gastrointestinal symptoms, lymphadenopathy, and rarely as meningitis, or with mucocutaneous and adrenal involvement. Diagnostic modalities include direct visualisation of the fungus in tissue specimens, Histoplasma antigen detection in blood or urine, antibody detection, detection of DNA sequences by PCR, and culture of clinical specimens. Treatment is based on disease severity, with a long course of itraconazole and induction therapy with amphotericin B for moderate to severe infection. HIV patients with a CD4 count of <150 cells/μL in endemic areas with high disease incidence require prophylaxis. We report a case of a 35-year-old male with HIV infection who presented with diarrhoea and abdominal pain. Evaluation revealed retroperitoneal, mesenteric, supraclavicular lymphadenopathy, splenomegaly, ileitis, and colitis. Terminal ileum mucosa and supraclavicular lymph node biopsy specimens showed Histoplasma capsulatum on pathology with a positive tissue fungal culture. He was successfully treated with Itraconazole with symptomatic improvement.