Evidence and consensus on best practices on the management of human bite injuries is lacking. Our objective was to identify factors that are associated with delay to emergency department (ED) presentation, antibiotic usage and patient admission.

We present a retrospective chart review of adults treated for human bites. Multivariable logistic regression models used demographic characteristics and bite circumstances and characteristics as factors associated with ED presentation more than 24 hours after the bite, antibiotic usage and hospital admission.

Of the 388 patients evaluated for a human bite, 66.5% were bitten during an altercation; 23.8% presented more than 24 hours after the bite; 50.3% were bitten on the hands or fingers, 23.5% on an extremity and 17.8% on the head or neck. Only 7.7% of all patients sustained closed-fist injuries; the majority had occlusional or other kinds of bites. The majority of patients (77.3%) received antibiotics and 11.1% were admitted to hospital. Patients who had greater odds of presenting more than 24 hours after the bite were black (odds ratio [OR] 1.79, 95% confidence interval [CI] 1.02–3.13), Hispanic (OR 2.68, 95% CI 1.22–5.89) and those who had a non-occupational bite (OR 3.87, 95% CI, 1.68–8.90). Patients had a greater chance of receiving antibiotics if they were bitten during an altercation (OR 1.87, 95% CI, 1.09–3.20) and were bitten on the hands or fingers (OR 2.23, 95% CI 1.31-3.80). Patients had a greater chance of being admitted to the hospital if they were bitten during an altercation (OR 4.91, 95% CI 1.65–14.64), bitten on the hands or fingers (OR 5.26, 95% CI, 1.74–15.87) and if they presented ≥ 24 hours after the bite.

Most patients presented to the ED within 24 hours of their injury and received antibiotics. The circumstances surrounding the bite appeared to be associated with delay to ED presentation, receipt of antibiotics and admission to the hospital. There are ethnic background differences in delay to ED presentation. ED clinicians in our study favour antibiotic usage and admission based on the body location of the bite, despite little evidence to support these practices.