[The microbiology of peritonsillar abscesses]

Peritonsillar abscess (quinsy) is a complication of acute bacterial tonsillitis. Its treatment remains controversial. One element of controversy is the choice of antibiotics after surgical drainage of the abscess. Results of many studies support the resistance of grown bacteria to many antibiotics and the potential importance of anaerobic species in development of peritonsillar abscesses.

The purpose of the study was to investigate bacteriology of peritonsillar abscesses in the group of own patients in an attempt to establish optimal method of antibiotic treatment after drainage of the abscess.

Abscess material from 12 patients aged 20-43 years (mean: 31.5, s.d.: 6.8), 4 women and 8 men, with peritonsillar abscesses was obtained by aspiration and sent for aerobic and anaerobic cultures. All patients were subsequently treated with oral phenoxymethylpenicillin (4.5 million units per day) and metronidazole (1500 mg per day).

A total 18 bacterial isolates (9 anaerobic and 9 aerobic and facultative) were recovered, accounting for 1.5 isolate per specimen. Anaerobic bacteria only were present in 3 patients, aerobic and facultatives in 3, and mixed aerobic and anaerobic flora in 6. Single bacterial isolates were recovered in 6 infections. The predominant bacterial isolates were Streptococcus and Bacteroides. Recovery in all examined subjects was complete.

In the routine management of peritonsillar abscess, bacteriologic studies are unnecessary on initial presentation. It is, however, necessary to consider infection with anaerobes, hence we recommend penicillin and metronidazole as the antibiotic regimen of choice in the treatment of peritonsillar abscesses.