Antibiotics after rattlesnake envenomation.

To record the outcome, with regard to infection rate, of patients with rattlesnake bites (RSBs) who do not receive prophylactic antibiotics, a prospective observational study was performed of patients with RSBs treated at our institution during a consecutive 18-month period. The inclusion criteria were RSBs <24 h old and completion of follow-up (telephone call, mail reply, medical toxicologist, or private physician examination) 7-10 days following envenomation. Fifty-six consecutive patients (Median age: 32.8 years [range 4-67 years]) were enrolled. One patient was excluded because of presentation 38 h after envenomation and two patients failed to complete the required follow-up. One patient received a dose of antibiotics before transfer. Antibiotics were discontinued upon arrival. Of the total 56 RSB patients, 34 (61%) RSBs involved the upper extremity and 22 (39%) involved the lower extremity. Six patients (11%) applied ice and two (4%) used a tourniquet before evaluation. The mean arrival time was 2.7 h (Range <1-24 h). Forty-three patients (81%) received antivenin. Fifty-three patients (100%) had extremity swelling and 38 patients (72%) had tender proximal lymph nodes. Of the 53 patients who completed the study, 3 (6%) received antibiotics from their primary care physicians at 7-10 day follow-up, with no cases (0%) of documented infection. Prophylactic antibiotics are not indicated in patients with rattlesnake bites.