Lack of accrual. We were unable to enroll enough participants to have meaningful results.

This pre-post study, designed to decrease unnecessary antibiotic prescribing, will use a prospective cohort of patients presenting to the Pediatric Emergency Department (PED). Patients with local skin findings that the clinician believes are primarily due to an insect bite or sting will be approached for the study.

The intervention will occur at the physician level. Midway through the study, physicians will receive an educational intervention describing how to differentiate cellulitis from allergic reaction using point-of-care bedside ultrasound.

The main outcome observed will be whether or not the patient receives a prescription for antibiotics at the index visit.

Thousands of children each year develop soft tissue swelling after an insect bite or sting and present shortly after to emergency departments (ED) across the United States. These wounds are particularly pruritic and can become self-inoculated with skin flora resulting in cellulitis. Clinicians who suspect cellulitis will typically prescribe oral antibiotics to treat this condition. Cellulitis, however, can be confused with a local allergic reaction to the insect bite because the physical examination findings are nearly identical. As such, the reliability of clinical examination in the diagnosis of pediatric skin and soft tissue infections is poor. Consequently, many patients with local allergic reactions are treated unnecessarily with antibiotics.

Patients who take antibiotics may experience unintended and unpleasant side effects such as diarrhea and allergic reactions. Moreover, unnecessary antibiotic prescribing is an important factor in the development of antibiotic-resistant infections which are estimated to affect 2 million patients and result in 23 thousand deaths each year in the United States. The medical community has thus sought innovative approaches to reducing unnecessary antibiotic use.

The goal of this study is to reduce unnecessary antibiotic prescriptions for children with insect bites that are not infected. This quality improvement initiative will focus on children with insect bites presenting to the Pediatric Emergency Department at Jacobi Medical Center (Bronx, NY). The pre-intervention phase will consist of patients enrolled prior to the physicians receiving a Point-of-Care Ultrasound (POCUS) Educational Intervention. The post-intervention phase will consist of patients enrolled after the physicians have received a POCUS Educational Intervention. In both phases, the physician will be able to care for the patient however he or she believes is appropriate.

The POCUS Education Intervention will supplement the baseline knowledge of the Pediatric Emergency Medicine physician with regards to performing a soft-tissue examination using POCUS. A POCUS expert will train all clinicians how to properly perform a soft tissue examination using POCUS to differentiate between cellulitis and local reactions due to angioedema/allergic reaction. The education will include a formal lecture and practical clinical examination. The proportion of patients receiving antibiotics will be compared before and after the Educational Initiative had started. All patients will be contacted 3 to 5 days after their initial emergency department visit to determine if the patient's condition worsened, if the patient needed to return to a healthcare provider, and if the patient had taken any antibiotics.

Inclusion Criteria:

- Erythema or swelling surrounding an insect bite or sting for greater than 12 hours

Exclusion Criteria:

• Patients with skin findings consistent with an abscess (ie. active drainage, fluctuance)
• Patients who are relatively immunocompromised (e.g., patients with AIDS, diabetes mellitus, cancer)
• Recent use of antibiotics within 1 week prior to symptoms
• Pregnant
• Altered mental status
• Unable to provide a phone number for follow-up

All participants in the study (i.e., patients and physicians) will be aware of what arm of the study they are in.