Pediatric Histoplasmosis in an Area of Endemicity: A Contemporary Analysis

Abstract

Background: Data on pediatric histoplasmosis have been limited to those from outbreak and case reports. We sought to evaluate the contemporary clinical manifestations, laboratory findings, and outcomes in children with histoplasmosis living in an area of endemicity.

Methods: This study was a single-center retrospective review of proven and probable cases of histoplasmosis in children aged 0 to 18 years between April 2008 and April 2014. Case ascertainment was ensured by us using International Classification of Diseases, Ninth Revision codes cross-referenced with laboratory, microbiology, and histopathology tests that detected Histoplasma capsulatum. Demographics, diagnostics, clinical management, and outcomes were evaluated.

Results: Seventy-three children with histoplasmosis (41 males; median age, 13 years [range, 3-18 years]) were diagnosed with proven (n = 17 [23%]) or probable (n = 56 [77%]) histoplasmosis, which manifested as pulmonary (n = 52 [71%]) or disseminated (n = 21 [29%]) disease. Symptoms at presentation were nonspecific; the examination of 21 (29%) patients revealed abnormal physical findings. Detection of H capsulatum by serologic methods occurred in 93% (63 of 68) of the patients tested. Histoplasma antigen in blood or urine was detected in 42% (20 of 48) and 28% (15 of 53) of the patients tested, respectively. The 16 (22%) patients who were immunocompromised had significantly higher rates of disseminated disease (56% vs 21%, respectively; P = .01), antigenuria (62% vs 18%, respectively; P = .004), and antigenemia (69% vs 31%, respectively; P = .02) and longer durations of antigenuria (403 vs 120 days, respectively; P = .003) and antigenemia (451 vs 149 days, respectively; P < .0001) than did the immunocompetent children.

Conclusions: Pediatric histoplasmosis manifests most frequently as pulmonary disease. The highest diagnostic yield was achieved when multiple diagnostic modalities were used. Presentation with disseminated disease and evidence of antigenemia, antigenuria, and delayed antigen clearance were more likely to be seen in immunocompromised children.

Keywords: children; histoplasmosis; immunocompromised.