325 - Novel Use of Point of Care Ultrasound in Pediatric Extremity Cellulitis

Poster Number: 325
Publication Number: 325.342

Background: Point of care ultrasound (POCUS) has been found to be useful in the differentiation of cellulitis and abscesses given their unique POCUS findings. Extending the dermatologic POCUS exam may provide more objective information in cellulitis disease monitoring, especially amongst diverse skin tones. We hypothesized that POCUS subcutaneous (sQ) edema changes may occur before or be greater than external manifestations, and that this should be the same across skin tone types.

Objective: To characterize and compare daily changes in cellulitis POCUS and physical exam findings for hospitalized pediatric patients with diverse skin tones.

Design/Methods: This is a prospective observational study of participants admitted with cellulitis to a general pediatrics inpatient service. Inclusion criteria are: age 3 months to 17 years, antibiotic initiation within the last 24 hours, admission diagnosis of unilateral extremity cellulitis. Comorbidities that would confer baseline extremity edema were excluded. POCUS was performed by study investigators and the sonographic edge of sQ edema was drawn daily. All enrolled patients had images reviewed by one consistent investigator. A standardized review document was created including time to complete POCUS, erythema and sQ edema measurements, physician cellulitis assessment, and physician certainty of visual erythema daily improvement.

Results: Nine patients are enrolled in this study (44.4% White, 11.1% Black, 44.4% Hispanic; Table 1); enrollment is ongoing. Within the first 24 hours of antibiotics, POCUS sQ edema length extended further than demarcated skin erythema in all patients (median 7.5 cm). Average time to complete POCUS was 7.3 minutes. POCUS width measurements could not be obtained in all participants due to limitations from circumferential edema. In the majority of participants, 77.8%, POCUS border length changes occurred earlier or were more pronounced in comparison to skin erythema (Fig. 1). POCUS measurements regressed during each hospitalization corresponding with clinical improvement. Three providers, 33.3%, reported being ‘somewhat certain’ on hospitalization day two that the patient’s cellulitis was visually improving and for these patients one had decreasing POCUS sQ edema borders, one had extension, and one was unchanged.

Conclusion(s): POCUS can quickly and objectively measure extent of cellulitis amongst various skin tone types. We also found that sQ edema was more extensive and exhibited changes earlier than external findings. Following sQ edema can be a novel way to monitor the clinical evolution of pediatric cellulitis in all skin tones.