Role of bacterial biofilms in idiopathic childhood epistaxis.

The objective of the study is to conduct a prospective trial investigating the possible role of bacterial biofilms in the pathogenesis of severe idiopathic childhood epistaxis. This study included 84 cases of severe idiopathic epistaxis, aged below 16 years, who were prepared for cautery under general anesthesia. A nasal swab was taken for bacterial culture and a nasal mucosal specimen (≤ 3 mm(2)) was taken from the suspected site of bleeding just prior to cautery and sent for bacterial identification by pathogen specific fluorescence in situ hybridization (FISH) and also for detection of bacterial biofilms by scanning electron microscope (SEM). Nasal mucosal specimens from 20 children of the same age prepared for reduction of fracture nasal bones and have no nasal problems were taken as a control group. Bacterial culture was positive in 27.3 % of patients and the most common organism was Staphylococcus aureus (19 %). By SEM, biofilm formation was detected in only six patients (7.1 %). Evaluation of nasal specimens with FISH was positive for pathogenic bacteria in 37 % of cases; the most common organism was S. aureus (22.6 % of cases). In the control group, no biofilm was detected by SEM and no pathogenic bacteria were cultured or detected by FISH. The difference between the two groups was statistically significant. Bacterial biofilm does not seem to play a major role in the pathogenesis of idiopathic epistaxis in children (only positive in 7.1 % of cases by SEM) although a low-grade chronic inflammation is not infrequently present (37 % of cases detected by FISH). FISH is more sensitive than bacterial culture in detecting bacterial infections. S. aureus was the most common pathogen detected by both techniques.