Treatment outcomes of acute streptococcal tonsillitis according to antibiotic treatment. A retrospective analysis of 242,366 GABHS tonsillitis cases treated in the community.

Mattan Bar-Yishay, Ilan Yehoshua, Avital Bilitzky, Yan Press

Keywords: Tonsillitis, Pharyngitis, Antibiotic treatment, Penicillin, Benzathine Penicillin, Penicillin G, Upper respiratory tract infections, Primary care, Peritonsillar abscess, Post-streptococcal glomerulonephritis, Rheumatic fever, Post-streptococcal arthritis, Sydenham chorea.


Tonsillitis caused by Group-A Beta-Hemolytic Streptococcus (GABHS) is a common cause for primary physician visits and antibiotic treatment.

Research questions:

Does the type of antibiotic treatment used affect the number of additional primary physician visits or the development of complications?


This retrospective study included first cases of culture-confirmed GABHS-tonsillitis who received appropriate antibiotic treatment in the community. Records were reviewed according to type of antibiotic treatment purchased. Primary outcomes were the number of additional primary physician visits within 30, 60 and 90 days from diagnosis. Secondary outcomes were the number of complications within 90 days, including peritonsillar abscess, post-streptococcal glomerulonephritis, rheumatic-fever, post-streptococcal arthritis, chorea and death.


The study included 242,366 participants (55.3% female, 57.6% aged 3-15years). Majority of cases were treated with amoxicillin (n=134,266, 55.4%), followed by penicillin-V (phenoxymethylpenicillin, n=79,109, 32.6%), macrolides (n=15,046, 6.2%), amoxicillin/clavulanate (n=9,077, 3.7%), cephalosporins (n=4,601, 1.9%), and rarely intramuscular benzathine-penicillin (n=267, 0.1%).
On multivariate analysis, compared to penicillin-V treatment, adjusted incidence rate-ratios (IRR) for additional primary physician visits at 30-days were IRR=1.46 (CI 1.33-1.60, p<0.001) for benzathine-penicillin treatment, IRR=1.27 (CI 1.24-1.30, p<0.001) for cephalosporin treatment, IRR=1.15 (CI 1.13-1.17, p<0.001) for macrolide treatment, IRR=1.12 (CI 1.09-1.14, p<0.001) for amoxicillin/clavulanate treatment, and IRR=1.07 (CI 1.06-1.08, p<0.001) for amoxicillin treatment.
Compared to penicillin-V, patients treated with amoxicillin showed decreased adjusted odds-ratios (aOR) of developing a peritonsillar or retropharyngeal abscess (aOR=0.75, CI 0.55-1.02, p=0.07), or developing any complication (aOR=0.68, CI 0.52-0.89, p=0.006). Benzathine-penicillin treated patients showed the highest rates of peritonsillar or retropharyngeal abscess (aOR=8.61, CI 2.71-27.38, p<0.001), or any complication (aOR=10.77, CI 4.37-26.56, p<0.001).


Treatment of acute GABHS-tonsillitis in the community with penicillin-V was significantly associated with fewer additional primary physician visits compared to other antibiotic treatments. Treatment with amoxicillin was significantly associated with reduced development of the rare but serious complications of GABHS-tonsillitis compared to other antibiotic treatments, including penicillin-V.

Points for discussion: