Case Presentation: A 67-year-old male with a history of hypertension, asthma, and ulcerative colitis status post-colectomy presented to the Emergency Department (ED) with a month-long history of malaise, cough, shortness of breath, and subjective fevers. Despite multiple visits to urgent care, where he received antibiotics and steroids, his symptoms persisted. On ED arrival, the patient was febrile, mildly hypoxic, and had wheezing. Imaging revealed patchy right basilar airspace disease, consistent with chronic obstructive pulmonary disease (COPD), but a subsequent CT scan showed multifocal consolidations and ground-glass opacities, suggesting diffuse lung involvement. Laboratory tests revealed leukocytosis and acute kidney injury. Cultures for common pathogens, including COVID-19, Influenza, Mycoplasma pneumoniae, and bacterial species, were negative. Given the clinical presentation and lack of response to antibiotics, bronchoscopy with bronchoalveolar lavage (BAL) was performed, which showed budding yeast consistent with Blastomyces dermatitidis. Serological testing also confirmed Influenza A. The patient was started on intravenous liposomal amphotericin B (AmBisome) and monitored closely for renal function and clinical response.
Discussion: Blastomycosis is a rare fungal infection caused by Blastomyces dermatitidis and Blastomyces gilchristii, endemic in specific regions of North America, particularly near the Ohio and Mississippi Rivers, the Great Lakes, and St. Lawrence Seaway. It is acquired by inhaling fungal conidia, leading primarily to pulmonary infection, with potential for extrapulmonary dissemination. The disease presents with a broad spectrum of symptoms, from mild pneumonia to severe, life-threatening conditions, including acute respiratory distress syndrome (ARDS) and systemic dissemination, often mimicking bacterial pneumonia.In this case, the patient’s persistent symptoms, negative bacterial and viral cultures, and imaging findings that did not suggest a typical bacterial pneumonia raised suspicion for a fungal cause. The identification of Blastomyces in the BAL fluid confirmed the diagnosis. Notably, the patient had a concurrent Influenza A infection, complicating his clinical presentation and highlighting the importance of considering multiple pathogens in cases of prolonged respiratory illness.Diagnosis is confirmed by culture or direct visualization of the yeast in respiratory samples. Urine and serum antigen tests offer additional diagnostic support, particularly in critically ill patients. Early diagnosis and treatment are critical for preventing complications, and therapy typically involves liposomal amphotericin B for severe cases, followed by itraconazole for longer-term management. This case underscores the importance of considering rare fungal infections, such as blastomycosis, in patients with non-resolving pneumonia, especially when common bacterial and viral causes have been ruled out.
Conclusions: Blastomycosis can mimic bacterial pneumonia and complicate other infections, as seen with Influenza A in this case. Clinicians should consider fungal infections in patients with persistent respiratory symptoms when common pathogens are excluded. Early diagnosis and antifungal treatment are vital for better outcomes. This case underscores the need to include rare pathogens in the differential diagnosis and highlights the importance of advancing diagnostic and treatment approaches for blastomycosis.
