A clinical decision rule for the use of ultrasound in children presenting with acute inflammatory neck masses.

OBJECTIVE: To identify the association between clinical and ultrasound findings and surgical drainage in children with inflammatory neck masses and to create a clinical decision rule that allows for reduction of unnecessary use of ultrasound in inflammatory neck masses.
MATERIALS AND METHODS: We reviewed data on patients ≤18 years who visited our emergency department between 2012 and 2014 with inflammatory neck swelling and who underwent ultrasound examinations of the neck. We used multivariate logistic regression to identify factors associated with drainage within 24 h of ultrasound study (early drainage). Recursive partitioning was used for risk stratification.
RESULTS: Of 341 consecutive patients included in this study, 37 patients underwent early drainage and all had purulent material drained. All patients but one with non-suppurative adenitis and 95% (97/102) of those with suppurative adenitis or early/suspicious abscess on ultrasound were initially treated medically. Of those with a definite diagnosis of abscess/fluid collection, 89% (32/36) underwent early drainage. Patients who underwent drainage were more likely to be younger, female and have a longer duration of neck swelling, with fluctuance and erythema on exam. Recursive partitioning analysis revealed that among children with neck swelling >3 days and ≤3 days, the rate of early drainage was 24.3% and 4.4%, respectively. None of the children >7 months with neck swelling ≤3 days underwent early drainage.
CONCLUSION: Children older than 1 year with inflammatory neck swelling ≤3 days are at low risk of having ultrasound findings that require drainage. In this subgroup of patients, ultrasound could be avoided unless the patient fails to improve after a trial of antibiotic therapy.