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A5389 - Rapidly Progressing Necrotizing Pneumonia Secondary to Blastomycosis
Author Block: K. Pennington1, T. Peikert2, P. Escalante2; 1Mayo School of Graduate Medical Education, Rochester, MN, United States, 2Mayo Clinic, Rochester, MN, United States.
Introduction: Pulmonary Blastomycosis can present in a variety ways: as an acute necrotizing pneumonia, as chronic pneumonia (often confused with pulmonary malignancy), or as acute respiratory distress syndrome with a miliary pattern. Secondary to the wide variety of clinical manifestations and insensitive/non-specific serologic studies, pulmonary Blastomycosis can be a diagnostic challenge. We present a case of rapidly progressing necrotizing pneumonia secondary to pulmonary Blastomycosis in a patient with mixed serologic findings. Case: A healthy 34-year-old woman presented to the emergency department with a 7-day history of pleuritic chest pain, shortness of breath and productive cough. She was evaluated at an outside emergency department approximately 5-days prior and was diagnosed with a right-sided pneumonia. She was prescribed a 5-day course of azithromycin but continued to have progressive pain and dyspnea prompting her to seek additional care. Medical history was only notable for severe gastro-esophageal reflux disease status-post Nissen’s fundoplication 5 years prior, and social history was remarkable for a camping trip to the Minnesota Boundary Waters 4 weeks prior. On physical examination, she was mildly hypoxemic requiring nasal cannula. Initial laboratory evaluation showed a mild leukocytosis with neutrophil predominance and mild normocytic anemia. Chest x-ray revealed a dense opacity occupying the majority of the right hilar region that had progressed since the outside chest x-ray. Computed tomography of the chest showed a dense consolidation of the anterior segment of the right upper lobe with ill-defined regions of low attenuation consistent with necrosis. Sputum samples were notable for broad-based, budding yeast on calcofluor-white stain, consistent with Blastomycosis. Prior to obtaining a positive sputum sample, fungal urine and serum studies were collected. These were notable for positive serum Blastomyces antibodies by enzyme-linked immunoassay (ELISA), negative serum Blastomyces antibodies by immunodiffusion, and positive Histoplasma urine antigen. Brain MRI for headaches was unrevealing. Because of rapid progression of her pneumonia, she was initiated on liposomal amphotericin B and itraconazole with plan to convert to itraconazole monotherapy to complete a 6 month course. Conclusion: Serologic antibody and urine antigen testing for pulmonary Blastomycosis is often obtained but is insensitive and non-specific even in patients with positive sputum fungal smears/cultures. ELISA antibody detection is the most sensitive serologic test but may be positive with other endemic fungal infections. Immunodiffusion techniques have low sensitivity and are often negative in active infection as demonstrated here. Additionally, urine antigen testing for histoplasma is often positive in acute blastomycosis infection.