Dimorphic fungi — MCQs

A 45-year-old HIV-positive patient (CD4 count 180 cells/µL) from San Joaquin Valley presents with erythema nodosum, arthralgias, and bilateral hilar adenopathy. Coccidioides serology shows IgM positive, IgG negative. He is asymptomatic except for joint pain and skin lesions. He is on antiretroviral therapy with undetectable viral load. Evaluate the clinical presentation and synthesize the appropriate management decision considering immune status and disease manifestations.

A 58-year-old man with acute myeloid leukemia presents with breakthrough fungal infection while on fluconazole prophylaxis. Blood cultures grow yeast that forms germ tubes. Chest CT shows new pulmonary nodules. He has neutropenia (ANC 200/µL) and is 2 weeks post-chemotherapy. His serum creatinine is 2.8 mg/dL. Evaluate and synthesize the optimal therapeutic strategy considering drug resistance, organ dysfunction, and underlying malignancy.

A 35-year-old pregnant woman in her third trimester from Arizona presents with fever, severe dyspnea, and diffuse pulmonary infiltrates. Serologic testing confirms acute coccidioidomycosis with high complement-fixing antibody titers. She has no history of immunocompromise. Evaluate the risk stratification and synthesize the optimal management approach considering both maternal and fetal outcomes.

A 50-year-old renal transplant patient on immunosuppression presents with skin lesions, pulmonary infiltrates, and bone lesions. Biopsy shows broad-based budding yeast. He was previously treated for pulmonary blastomycosis 5 years ago in Wisconsin. Urinary Blastomyces antigen is positive. Analyze the clinical scenario to determine the optimal management strategy considering his transplant status.

A 42-year-old spelunker develops progressive dyspnea and a cavitary lung lesion on chest CT. Sputum shows small yeast forms within macrophages. Culture at 37°C shows yeast, while culture at 25°C shows hyphae with tuberculate macroconidia. He has been exploring caves in Ohio. Analyze the host-pathogen interaction and immune response to determine the most critical factor determining disease severity.