Utility of Trimethoprim-sulfamethoxazole Use in Skin Abscess Management

A Double Blinded Randomized Controlled Trial for the Management of Pediatric Community Acquired Skin Abscesses - To Treat or Not to Treat With Antibiotics

The purpose of this study is to determine if antibiotics are required in the management of skin abscess following incision and drainage.

This is a double-blind, randomized controlled trial at an urban pediatric emergency department. Sample size (162) was based on a threshold equivalence of 7% (α = 0.05, power = 80%). Inclusion criteria were: non-toxic, immunocompetent, 3 months to 18 years old, English-speaking patients with clinical or ultrasound identified skin abscesses who were not on antibiotics. Patients were block randomized to receive placebo or trimethoprim/sulfamethoxazole following incision and drainage. Follow-up was a call at 2-3 days & a repeat visit or call at 10-14 days. Treatment failure was defined as: persistent erythema, tenderness, and/or draining lesions. New lesion was defined as: primary resolution with development of new lesion (furuncle, carbuncle or abscess) at a different location. Compliance was evaluated by the return of the study medication or by patient report.

Participants were randomized to receive placebo or trimethoprim/sulfamethoxazole using a computer randomization program on the initial presentation. The placebo is a Maalox and tonic water combination that resembled the antibiotic in color, texture and taste. The antibiotic dose is a standard trimethoprim/sulfamethoxazole for bacterial infection (10-12mg trimethoprim/kg/day, with a maximum adult dose of 160mg trimethoprim/day, divided into two doses). The concentration of the liquid is 200mg sulfamethoxazole/40mg trimethoprim per 5mL. With a maximum dose of 160mg trimethoprim, this equates to 20mL.

Placebo (Maalox with simethicone and bitter mixture) suspension was dispensed to study participants who were block randomized to receive the placebo.

The secondary outcomes of interest included the development of new lesions at a different site (>5cm away from original skin abscess) on day 10 clinical follow-up or self-report and 3 month telephone follow-up.

Inclusion Criteria: non-toxic patients immunocompetent patients 3 months to 18 years old English-speaking patients skin abscesses not on antibiotics Exclusion Criteria: toxic patients immunocompromising co-morbidities less than 3 months old or older than 18 years of age non-english speaking on antibiotics

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