Dog Bite

Figure Each year, more than 4.7 million Americans are bitten by a dog. Of those, about 800,000-half of whom are children-seek medical attention.

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The majority of reported animal bites are dog bites. Accordingly, the CDC has named the third week of May National Dog Bite Prevention Week; several suggestions for dog bite prevention are available from the CDC Web site.

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The 2-year-old boy shown here had been bitten on the left cheek by a medium-sized dog while at the home of his day-care provider. Immediately after the incident, the child was examined by his pediatrician and given a presciption for amoxicillin clavulanate. The next day, he presented to the emergency department with worsening cellulitis of the left cheek.

The child was afebrile, alert, and responsive. He had a 1-cm scab in the center of a shiny, swollen, and erythematous area that extended from the lower eyelid to the submandibular region on the left side (outlined in marker). The area was warm to touch and tender on palpation. A 22-cm indurated area was palpable around the scab from which there was mild drainage after manipulation. The child's vaccination history was up-to-date.

He was treated with intravenous ampicillin/sulbactam. After 2 days, there was significant clinical improvement, blood and wound cultures showed no growth, and he was discharged to complete oral therapy at home.

Bites can come in many forms, including punctures, abrasions, and tears; bites from large animals may involve crush injuries.² A diagram of the entire wound and a clear description of its size and depth should be recorded during the physical examination. Obtaining the vaccination history of the child and the offending animal is essential. A potentially rabid animal must be located and either observed or killed. Depending on the type of animal and its locality, rabies vaccine may be administered, and hyperimmunoglobulin may be required. The animal in this case had received the rabies vaccine. When the patient's tetanus status is unknown or the child has received fewer than 3 doses, administer tetanus vaccine as appropriate.³

Prophylactic antibiotic therapy for bite wounds is common. Wound infections are often caused by the oral flora of the biting animal; Pasteurella multocida and Pasteurella canis are common isolates. Treatment should cover P multocida, Staphylococcus aureus, and anaerobes.⁴ This may include amoxicillin clavulanate for 3 to 5 days with outpatient follow-up within 24 to 48 hours. If symptoms worsen despite outpatient therapy-as was the case in this child-intravenous antibiotics (ampicillin/sulbactam or cefoxitin) are used.

Copious irrigation of the bite wound with normal saline is also required. If edema is present, the area should be elevated.⁴ Wound and blood cultures should also be performed. Sutures may be placed after irrigation and debridement; the general practice is to approximate the wound, which then heals by primary or secondary intention. For facial wounds, the area is sutured fully after irrigation and antibiotic use.⁴ A radiograph is indicated for a suspected fracture. Hot compresses to decrease swelling are helpful.

References:

• Centers for Disease Control and Prevention. Injury Center. National Dog Bite Prevention Week. http://www.cdc.gov/ncipc/duip/biteprevention.htm. Updated September 27, 2007. Accessed March 26, 2008.

• Ball V, Younggren BN. Emergency management of difficult wounds: part I. Emerg Med Clin North Am.

• Presutti RJ. Prevention and treatment of dog bites. Am Fam Physician. 2001; 63:1567-1572.

• Goldstein EJC. Bites. In: Mandell GL, Bennett JE, Dolin R, eds. Principles and Practice of Infectious Diseases. 6th ed. Philadelphia: Churchill Livingstone; 2005:3552.2007;25:101-121.