Pediatric histoplasmosis most frequently manifests as pulmonary disease, and the highest diagnostic yields were achieved when multiple diagnostic modalities were used, according to research in the Journal of the Pediatric Infectious Diseases Society.
A single-center retrospective review of probable and proven histoplasmosis cases in children aged 0 to 18 years, from April 2008 to April 2014, was used to evaluate the contemporary clinical manifestations, laboratory findings, and outcomes in children with histoplasmosis.
Histoplasmosis was diagnosed as proven in 17 children and probable in 56. The median age of patients was 13 years (range 3-18 years), and 41 of the 73 were male. Histoplasmosis manifested as pulmonary or disseminated disease in 71% and 29% of cases, respectively. Histoplasma capsulatum was detected by serologic methods in 93% of 68 patients tested, and the Histoplasma antigen was detected in the blood of 20 of the 48 tested and urine in 15 of 53 tested. Sixteen patients were immunocompromised and compared with immunocompetent children, they 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).
The retrospective design and single-institution setting limited the study, which led to small sample sizes, a lack of systematic testing algorithms, and possible selection biases. Also, consistent diagnostic evaluations were not performed for all patients, which likely biased the diagnostic yield of histopathology, tissue culture, and classification of proven disease. Serial antigen testing as well as convalescent serologic testing to find a 4-fold rise in their complement fixation titer was not performed for all participants, which limited diagnostic confirmation and created an inability to evaluate the performance characteristics of each testing modality. Finally, confounding factors may exist within the immunocompromised group that hinder interpretation of laboratory values.
The results demonstrated that histoplasmosis presented most frequently with pulmonary symptoms, and physical examination rarely provided additional information for diagnosis. Investigators also believe there is “need for a heightened clinical suspicion and diagnostic testing in any patient with presumed community-acquired pneumonia whose symptoms are severe or atypical or do not respond to antibiotic therapy.”
Ouellette CP, Stanek JR, Leber A, Ardura MI. Pediatric histoplasmosis in an area of endemicity: A contemporary analysis [published online August 14 2018]. J Pediatric Infect Dis Soc. doi: 10.1093/jpids/piy073
This article originally appeared on Infectious Disease Advisor