190 children consecutively undergoing bronchoscopy with bacterial cultures of bronchoalveolar lavage fluid (BALF) or bronchial aspirates (BA) from January 1999 until June 2001 were included in the study. 84 children were on topical corticosteroids
(TCS) therapy and 106 children were not. The incidences of detected significant amounts of pathologic bacteria from BALF and BA were not significantly different between children on TCS (16.67%) and children without TCS (18.87%). Haemophilus influenzae,
streptococcus pneumoniae and moraxella catarrhalis were the most common pathogens isolated from the BALF and BA in both groups of children with and without TCS. TCS, previous systemic steroid therapy, passive smoke exposure, antibiotic pre-treatment and
premature birth neither had any influence on the incidence of bacterial pathogens in the lower respiratory tract nor on the types of bacteria involved.