Pediatric abscess characteristics associated with hospital admission from the ED

Sensitivity and Specificity of US and CT as Diagnostic Tools for Pediatric Lateral Neck Abscesses

OBJECTIVE

Ultrasound (US) and computed tomography (CT) are commonly used in the diagnosis of pediatric neck abscesses. The objective of this study is to determine the sensitivity and specificity of US and CT in the diagnosis of pediatric lateral neck abscesses, with a secondary objective of evaluating the association of specific clinical features with a positive US or CT scan.

STUDY DESIGN

Retrospective review of pediatric patients admitted to a tertiary care center from January 1, 2011, to December 31, 2020, with neck abscesses.

SETTING

Tertiary care center.

METHODS

The sensitivity and specificity of US and CT were calculated by comparing imaging performed within 24 h of incision and drainage (I&D). Multiple regression was used to evaluate the association of clinical features with a true positive US or CT.

RESULTS

There were 171 patients included in this study, with a median age of 1.5 years (interquartile range [IQR]: 1-5 years). I&D was done in 156 patients (91.2%), while 15 (8.8%) were treated with antibiotics. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of US were 69.5%, 80%, 96.6%, and 24.2%. The sensitivity, specificity, PPV, and NPV of neck CT were 95.5%, 80%, 95.5%, and 57.1%. Length of symptoms, skin erythema, and fluctuance were not significantly associated with a positive US (F(3, 82) = 0.24, p = .9, R²  = 0.01) or CT scan (F(3, 30) = 0.84, p = .5, R²  = 0.08).

CONCLUSION

Neck US has a low sensitivity for diagnosing pediatric neck abscesses, when compared to CT, but remains a useful initial investigation given its high PPV. Clinicians should have a low threshold for pursuing CT if there is a high suspicion of abscess formation.

LEVEL OF EVIDENCE

Level 4.

Evaluation of an imaging protocol using ultrasound as the primary diagnostic modality in pediatric patients with superficial soft tissue infections of the face and neck

OBJECTIVE

To determine the clinical impact of an initiative to use ultrasound (US) as the primary diagnostic modality for children with superficial face and neck infections versus use of computed tomography (CT).

METHODS

Children with a diagnosis of lymphadenitis, face or neck abscess, or face and neck cellulitis were retrospectively evaluated by the otolaryngology service. Patients were separated into two groups based on implementation of a departmental initiative to use US as the primary diagnostic modality. The pre-implementation cohort consisted of patients treated prior to the initiative (2006-2009) and the current protocol cohort consisted of patients treated after the initiative was started (2010-2013). Demographics, use of US or CT, necessity of surgical intervention, and failure of medical management were compared.

RESULTS

Three hundred seventy three children were evaluated; 114 patients were included in the pre-implementation cohort and 259 patients were included in the current protocol cohort for comparison. Patients presenting during the current protocol period were more likely to undergo US (pre-implementation vs. current protocol, p-value) (12% vs. 49%, p < 0.0001) and less likely to undergo CT (66% vs. 41%, p < 0.0001) for their initial evaluation. There were no differences in the percentage of children who underwent prompt surgical drainage, prompt discharge without surgery, or trial inpatient observation. There were also no differences in the rate of treatment failure for patients undergoing prompt surgery or prompt discharge on antibiotics. For those patients who underwent repeat evaluation following trial medical management, US was used more frequently in the current protocol period (4% vs. 20%, p = 0.002) with no difference in CT use, selected treatment strategy, or treatment failure rates.

CONCLUSION

Increased use of US on initial evaluation of children with superficial face and neck infections resulted in decreased CT utilization, without negatively impacting outcome. Decreasing pediatric radiation exposure and potential long-term effects is of primary importance.

Same-day discharge after incision and drainage of soft-tissue abscess in diaper-age children is safe and effective

PURPOSE

Many pediatric centers admit patients following incision and drainage (I&D) of soft-tissue abscesses. The purpose of this study is to assess the safety and efficacy of the same-day discharge following I&D.

METHODS

Retrospective review was performed of children aged 3 months-4 years who underwent operative I&D of an abscess followed by same-day discharge. Patients receiving antibiotics within 2 weeks of presentation were excluded. Treatment failure was defined as readmission or repeat procedure related to the initial abscess. Statistical analysis was performed using Wilcoxon Rank-Sum and Fisher's Exact tests.

RESULTS

There were 442 procedures performed in 408 patients. Mean age was 1.8 years. Fever was noted in 25.8%. Of those who had a white blood cell (WBC) count drawn, 59.7% had leukocytosis. Mean time from procedure to discharge was 2.3 h, and 85.0% were discharged with oral antibiotics. Treatment failure occurred in four (0.9%) and ten (2.3%) patients at 14 and 30 days, respectively. Mean WBC count was higher in the 14-day treatment failure group (24.1 versus 16.3; p = 0.10). In patients with leukocytosis, there were 2 (1.4%) treatment failures compared to none in those without leukocytosis.

CONCLUSION

Same-day discharge after I&D of abscess in diaper-age children is safe and effective.