Introduction Centor criteria (fever >38.5°C, swollen, tender anterior cervical lymph nodes, tonsillar exudate and absence of cough) are an algorithm to assess the probability of group A β haemolytic Streptococcus (GABHS) as the origin of sore throat, developed for adults. We wanted to evaluate the correlation between Centor criteria and presence of GABHS in children with sore throat admitted to our paediatric emergency department (PED).

Design Retrospective cohort study.

Setting The emergency department of a large tertiary university hospital in Brussels, with over 20 000 yearly visits for children below age 16.

Participants All medical records (from 2008 to 2010) of children between ages 2 and 16, who were diagnosed with pharyngitis, tonsillitis or sore throat and having a throat swab culture for GABHS. Children with underlying chronic respiratory, cardiac, haematological or immunological diseases and children who had already received antibiotics (AB) prior to the PED consult were excluded. Only records with a full disease history were selected. Out of a total 2118 visits for sore throats, 441 met our criteria. The children were divided into two age groups, 2–5 and 5–16 years.

Results The prevalence of GABHS was higher in the older children compared to the preschoolers (38.7 vs 27.6; p=0.01), and the overall prevalence was 32%. There was no significant difference in the prevalence of GABHS for all different Centor scores within an age group. Likelihood ratios (LR) demonstrate that none of the individual symptoms or a Centor score of ≥3 seems to be effective in ruling in or ruling out GABHS. Pooled LR (CI) for Centor ≥3 was 0.67 (CI 0.50 to 0.90) for the preschoolers and 1.37 (CI 1.04 to 1.79) for the older children.

Conclusions Our results confirm the ineffectiveness of Centor criteria as a predicting factor for finding GABHS in a throat swab culture in children.