The epidemiology, antibiotic resistance and post-discharge course of peritonsillar abscesses in London, Ontario

Background: Peritonsillar abscesses (PTA) are a common complication of tonsillitis. Recent global epidemiological data regarding PTAs have demonstrated increasing antimicrobial resistance patterns. No similar studies have been conducted in Canada and no Canadian study has examined the post-discharge course of treated patients. Methods: A prospective observational study of the epidemiology, antibiotic resistance and post-discharge course of patients presenting with a peritonsillar abscess to the Emergency Department in London, Ontario over one year. A follow-up telephone survey was conducted 2-3 weeks after abscess drainage. Results: 60 patients were diagnosed with an abscess, giving an incidence of 12/100,000. 46 patients were enrolled in the study; the average duration of symptoms prior to presentation was 6 days, with 51% treated with antibiotics prior to presentation. Streptococcus pyogenes and Streptococcus anginosus were present in 56% of isolates and of those, 7/23 (32%) of specimens demonstrated resistance to clindamycin. Eight patients were treated with clindamycin and had a culture that was resistant, yet only one had recurrence. Telephone follow-up was possible for 38 patients: 51% of patients reported a return to solid food within 2 days, and 75% reported no pain by 5 days. Resolution of trismus took a week or longer for 51%. Interpretation: Clindamycin resistance was identified in a third of Streptococcus isolates, which should be taken into account when prescribing antibiotics. Routine culture appears unnecessary as patients recover quickly from outpatient drainage and empiric therapy, with less pain than expected, but trismus takes time to resolve.