Risk factors for peritonsillar abscess in streptococcus A-negative tonsillitis: a case control study

The Centor criteria and the FeverPAIN score are recommended for guiding antibiotic prescription for tonsillitis, but they are not validated for this purpose. We aimed to identify risk factors for peritonsillar abscess in group A haemolytic streptococcus-negative tonsillitis and to test the performance of clinical scores and laboratory tests. In a retrospective case-control study at two regional hospitals from January 2015 to June 2018, we identified all cases of peritonsillar abscess and used propensity score matching utilising age and gender to select two controls per case from all patients who had a rapid group A haemolytic streptococcus antigen test in the emergency department. Exclusion criteria were age