Abstract
Mentor: Jennifer M. Davis Program: Internal Medicine – Infectious Diseases Type: Case Report Background: Histoplasmosis is a dimorphic fungus that often presents with symptoms of community-acquired pneumonia. Immunocompromised patients can also present with disseminated disease involving other organ systems. Case: A 25-year-old female with a past medical history of papillary thyroid carcinoma status post-surgical resection, dermatomyositis (managed with mycophenolate and monthly IVIG) presented to the emergency department with progressive shortness of breath associated with fevers, night sweats, and malaise. She had a new 2L oxygen requirement. Laboratory evaluation demonstrated pancytopenia (WBC 3,500, hemoglobin 9.7, platelets 129,000) and elevated liver function tests (AST 106 U/L, ALT 199 U/L, alkaline phosphatase 107 U/L). Chest CT chest and abdomen demonstrated diffuse submillimeter pulmonary nodules, a 1.6 cm pulmonary nodule, and splenomegaly. Serum 1,3 Beta D glucan returned elevated >500 pg/mL. The bronchoalveolar lavage (BAL) specimen showed fungal elements ( Figure 1). Aspergillus galactomannan was elevated at 7.91. Histoplasma antigen returned positive from BAL ( >25 ng/mL), serum ( >25.0 ng/mL), and urine ( >25 ng/mL). The patient received 6 days of intravenous liposomal amphotericin and was transitioned to oral itraconazole to complete 12 months of therapy for disseminated histoplasmosis. Figure 1 Bronchoalveolar lavage cytology with fungal yeast forms identified, consistent with Histoplasma. Conclusion: Patients with immunocompromising conditions are at increased risk for the development of disseminated histoplasmosis, and it is often difficult to assess the degree of a patient’s immunocompromise. The adrenal glands, liver, spleen, and bone marrow are often affected by disseminated disease. Diagnosis of Histoplasma capsulatum is often made by glycoprotein antigen testing, which has better sensitivity and specificity compared to culture. Providers should be aware of cross reactivity between aspergillus galactomannan, histoplasmosis antigens, and blastomycosis antigens.