The Melbourne Area, Systemic features, Swelling, Eye, Tenderness (ASSET) Score has demonstrated reliability, ease of use, and applicability as an indication for use of intravenous antibiotics in a child with cellulitis, according to research published in Pediatrics.

This prospective cohort study included 285 pediatric patients between the age of 6 months and 18 years who had a diagnosis of cellulitis. Based on an assessment at 24 hours, and regardless of modality of treatment started at admission, researchers assigned participants to 1 of 2 groups, to receive either oral (n=175) or intravenous (n=110) antibiotics. Univariate analysis was used to compare clinical and demographic characteristics. Continuous data was computed using a t-test, while categorical data was computed using a chi squared test. Survey data was collected from clinicians on which factors contributed to their decision regarding antibiotic choice.

Researchers identified 9 features that marked differences between the 2 groups: previous use of antibiotics; systemic features; area >1% body surface area; functional impairment; moderate-to-severe erythema, swelling, and tenderness; lymphangitis, involvement of periorbital region. These differences were used to compute the area under the receiver operating characteristic curve (AUC). For all 9 features the AUC was 0.89 (95% CI, 0.85-0.93).

To improve convenience and practicality, researchers iteratively reduced the number of features by 1, and found that fewest number of features for which the AUC remained high was 5— erythema, lymphangitis, functional impairment, and previous oral antibiotics were removed. Thus the researchers delineated the Melborne ASSET Score (maximum possible score of 7), and found it had an AUC of 0.86 (95% CI, 0.83-0.91); it yielded an 80% accuracy of classifying patients who required intravenous antibiotics, and was validated by the results in 251 participants. Deviating from this cutoff score resulted in greater numbers of potentially unnecessary intravenous treatments. A score of 3, for example, would increase sensitivity to 85%, but the specificity would decrease to 76%.

Limitations included the study being conducted in a hospital specialized for pediatrics, which may have resulted in less conservative approaches than in other hospitals and a low rate of Staphylococcus aureus resistant to methicillin.

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The study researchers concluded that the “Melbourne ASSET Score is the first risk assessment scoring system for pediatric cellulitis that is proposed to aid clinicians in deciding whether to treat with [intravenous] or oral antibiotics. It is simple, easy to use, applicable, and reliable. Although intended for widespread use, if limitations exist in other settings, it is designed to allow for refinement and is amenable to local impact analysis. We propose an impact analysis of this score, ideally in a different setting and population.”

Reference

Ibrahim LF, Hopper SM, Donath S, Salvin B, Babl FE, Bryant PA. Development and validation of a cellulitis risk score: the Melbourne ASSET score [published online January 3, 2019]. Pediatrics. doi: 10.1542/peds.2018-1420