Clinical and microbiological analysis of adult perianal abscess.

BACKGROUND: In Taiwan, Klebsiella pneumoniae is the predominant pathogen causing pyogenic liver abscess in patients with diabetes mellitus (DM). The purpose of our hospital-based study was to determine the predominant bacterial species causing perianal abscess in hospitalized patients with and without DM in Taiwan.

METHODS: Data on patients admitted and then operated on for perianal abscess during the period of March 2001 to December 2008 were reviewed. Information extracted from medical records included clinical information and laboratory data as well as culture and antibiotic sensitivity results.

RESULTS: A total of 183 patients underwent surgery for perianal abscess. The most common pathogen causing perianal abscess in non-DM patients was Escherichia coli (67.1%), and the most common pathogen isolated in DM patients was K pneumoniae (60%; p=0.009). Among the 25 patients with DM, incident DM was diagnosed in 24.0% (6 of 25). In addition, five patients had transient hyperglycemia.

CONCLUSIONS: Escherichia coli was the predominant pathogen isolated from perianal abscesses in patients without DM. Klebsiella pneumoniae, however, was the predominant pathogen isolated in DM patients. In both DM and non-DM patients, more than 90% of K pneumoniae isolates showed in vitro sensitivity to first-generation cephalosporins.