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A 44-year-old man with cough, arthralgia, and fever

      1. Case description

      A 44-year- old man presented with dry cough, diffuse joint pain, fevers, and night sweats for one month and poor appetite and weight loss for three months. Physical examination showed hepatosplenomegaly. A chest computed tomogram (Panel A and B) showed diffuse miliary nodules. Sputum for acid fast bacilli was negative. Testing for HIV-1 was positive with a high viral load and a low CD4 count of 4/µL. Bronchoscopy with bronchoalveolar lavage was performed. Gomori methenamine-silver stain of the bronchoalveolar lavage specimen showed intracellular yeasts within macrophages with narrow-based budding (Panel C).
      What is the diagnosis?
      Fig. 1.
      Figure 1
      Figure 1Figure 1 A an B. Computed chest tomogram showing diffuse miliary nodules, and C. Intracellular yeastswithin macropahges with narrow-based budding on Gomori methanamine-silver stain of bronchoalveolar lavage.

      2. Diagnosis

      Together with the clinical presentation, findings on imaging studies and bronchoalveolar lavage, a diagnosis of disseminated histoplasmosis with acquired immunodeficiency syndrome (AIDS) was established. The patient also tested positive for urine histoplasma antigen.

      3. Discussion

      Histoplasma capsulatum is a thermally dimorphic fungus transmitted via inhalation of spores from the soil in endemic areas which causes acute infection [
      • Wheat L.J.
      • Freifeld A.G.
      • Kleiman M.B.
      • et al.
      Clinical Practice Guidelines for the Management of Patients with Histoplasmosis: 2007 Update by the Infectious Diseases Society of America.
      ]. Some patients can develop disease many years after travel to an endemic area, consistent with reactivation of latent foci. T-cell immunity plays the predominant role in the recovery from histoplasmosis. Cytokines including IL-12 and interferon (IFN) gamma arm macrophages to kill the fungus and halt the progression of disease. Individuals with underlying conditions like AIDS with impaired defences are at risk for developing more severe and disseminated infection. Patients with AIDS frequently develop progressive disseminated histoplasmosis characterized by fever, night sweats, weight loss and hepatosplenomegaly [
      • Limper A.H.
      • Adenis A.
      • Le T.
      • Harrison T.S.
      Fungal infections in HIV/AIDS.
      ]. Urinary Histoplasma antigen has a high sensitivity of more than 90% for diagnosing disseminated disease in immunocompromised patients [
      • Limper A.H.
      • Adenis A.
      • Le T.
      • Harrison T.S.
      Fungal infections in HIV/AIDS.
      ]. Monitoring urinary Histoplasma antigen can also help with assessing treatment response, failure, and relapse [
      • Azar M.M.
      • Hage C.A.
      Laboratory diagnostics for Histoplasmosis.
      ]. Most common radiographic abnormalities are diffuse interstitial or reticulonodular infiltrates.
      Induction therapy with liposomal Amphotericin B for one to two weeks followed by maintenance therapy with itraconazole for a minimum of one year is recommended to prevent relapse. Anti-retroviral therapy should be initiated as soon as possible to improve cellular immunity. The patient was treated with liposomal amphotericin B for two weeks and is currently doing well on oral itraconazole and highly active anti-retroviral therapy.

      Contributors

      AM provided care for the patient. All authors wrote and revised the manuscript.

      Funding information

      This report received no specific funding.

      Informed consent

      written consent to publication was obtained.

      Declaration of Competing Interest

      There are no competing interests.

      References

        • Wheat L.J.
        • Freifeld A.G.
        • Kleiman M.B.
        • et al.
        Clinical Practice Guidelines for the Management of Patients with Histoplasmosis: 2007 Update by the Infectious Diseases Society of America.
        Clin Infect Dis. 2007; 45: 807-825
        • Limper A.H.
        • Adenis A.
        • Le T.
        • Harrison T.S.
        Fungal infections in HIV/AIDS.
        Lancet Infect Dis. 2017; 17: e334-e343
        • Azar M.M.
        • Hage C.A.
        Laboratory diagnostics for Histoplasmosis.
        J Clin Microbiol. 2017; 55: 1612-1620