Microbiology of abscesses of the head and neck in children.

Specimens from 36 children with abscesses of the neck and 31 children with abscesses of the head were cultured for aerobic and anaerobic bacteria. Antimicrobial therapy was administered to 51 of the 67 patients (76%) prior to sample collection. In specimens obtained from neck infections, aerobic bacteria only were recovered in 24 (67%), anaerobic bacteria only in seven (19%), and mixed aerobic and anaerobic bacteria in five (14%). In abscesses of the head, aerobic bacteria only were recovered in 11 (35%), anaerobic bacteria only in eight (26%), and mixed aerobic and anaerobic bacteria in 12 (39%). Of a total of 52 isolates recovered from neck abscesses (1.4 per specimen), 34 were aerobes (0.9 per specimen), and 18 were anaerobes (0.5 per specimen). Of a total of 62 isolates recovered from head abscesses (2.0 per specimen), 20 were aerobes (0.6 per specimen), and 42 were anaerobes (1.4 per specimen). The most frequently recovered organism in neck infection was Staphylococcus aureus (20 isolates), and the most frequently recovered organism in head infection was Bacteroides sp (19 isolates). beta-Lactamase activity was detected in 36 isolates recovered in 21 abscesses (46%). Correlation between the predisposing conditions and the bacteria recovered showed a higher recovery of anaerobes in patients with dental infection or manipulation, tonsillitis, and fetal monitoring. Staphylococcus aureus was associated with trauma. This study demonstrated the importance of anaerobic bacteria in abscesses in the head and neck, especially in infections originating from sites where these organisms are the predominant flora.