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A5672 - Endobronchial Histoplasmosis in a Pediatric Patient
Author Block: Y. Yu1, C. R. Esther2; 1University of North Carolina, Chapel Hill, NC, United States, 2Univ of North Carolina Chapel Hill, Chapel Hill, NC, United States.
Introduction: Histoplasmosis is a common endemic mycosis in the Mississippi and Ohio River valleys caused by the dimorphic fungus Histoplasma capsulatum. The clinical presentation of histoplasmosis varies ranging from asymptomatic infection to severe disseminated disease. Here we report a unique case of histoplasmosis presenting in a pediatric patient with endobronchial lesions. Case Report: A 3 - year - old male with a travel history significant for recent travel to Alabama and a past medical history significant for prematurity, mild subglottic stenosis, recurrent croup and protracted bacterial bronchitis on chronic azithromycin underwent scheduled bronchoscopy to evaluate his airway anatomy and obtain lower airway cultures. His bronchoscopy revealed improved subglottic narrowing, as well as unanticipated obstructive endobronchial lesions in the right bronchus intermedius and the right middle lobe orifice that were not present on airway evaluation the year prior. Biopsies of these lesions revealed small caliber fungal yeast forms consistent with Histoplasma. Repeat bronchoscopy one week after initial evaluation again showed endobronchial lesions. Bronchoalveolar lavage (BAL) cultures were significant only for oropharyngeal flora growth, with negative fungal stains and cultures. Laboratory evaluation demonstrated leukocytosis, positive serum titers for Histoplasma (1:128), and positive Histoplasma serum antigen, though BAL antigen was negative. Additional laboratory studies were negative for Blastomyces, Aspergillus, and Coccidiodes, and a basic immune profile was normal. Based on the above findings, he was diagnosed with endobronchial Histoplasma infection and started on voriconazole. Follow up five weeks after initiation of voriconazole showed a mild decrease in Histoplasma antigen, so treatment was continued with change to itraconazole. Discussion: Histoplasma capsulatum infection presents with a wide range of clinical manifestations with disease severity dependent on exposure and host immunity. While the majority of acute infections are asymptomatic, others may present as acute pulmonary histoplasmosis, subacute pulmonary histoplasmosis, chronic pulmonary histoplasmosis, mediastinal granuloma and progressive disseminated histoplasmosis. Histoplasmosis is diagnosed by histopathology and culture, cytology, complement fixation and immunodiffusion serology, or Histoplasma antigen detection, though demonstration of the fungi on histopathology or culture remains the gold standard. Treatment varies dependent on disease severity. When treatment is indicated, recommended antifungal agents include itraconazole and amphotericin B. This case report identifies a rare presentation of endobronchial histoplasmosis without clear evidence of immunosuppression, and illustrates the challenges associated with diagnosis and treatment.