Bite wounds

I Bite-wound infections generally are polymicrobial. On average, five different bacterial species can be isolated from an infected animal bite wound.3 Both the normal flora of the biter s mouth and that of the bite recipient s skin can be implicated. The bacteriology of the cat and dog mouth is quite similar. Pasteurella multocida, a gram-negative aerobe, is one of the predominant pathogens, isolated in up to 50% of dog and 75% of cat bites. S. viridans are the most frequently cultured bacteria from human bite wounds.3,43 Table 70-10 provides a comprehensive list of cat, dog, and human bite-wound pathogens. 

The clinical presentation of infected bite wounds is presented in Table 70-10. 

Complications of infected bite wounds include lymphangitis, abscess, septic arthritis, tenosynovitis, and osteomyelitis. Bites to the hand are particularly complication-prone.43,44... 

The goals of therapy for an infected bite wound are rapid and successful eradication of infection and prevention of related complications. 

Thorough irrigation with normal saline is the first step in the care of an infected bite wound. The wound should be elevated and immobilized. Surgical closure may be advocated, especially for facial wounds. Wounds that are infected, at higher risk for infection, or older than 24 hours should be left open because premature closure can lead to disastrous infectious complications.43... 

Most bite wounds require antibiotic therapy only when clinical infection is present. However, prophylactic therapy is recommended for wounds at higher risk for infection. These include human bites, deep punctures, bites to the hand, and bites requiring surgical repair.43... 

The most effective agent for the treatment (and prophylaxis) of human and animal bite-wound infections is amoxicillin-clavulanate. Alternatives for patients with significant penicillin allergies include either a fluoroquinolone or TMP-SMX in combination with clindamycin. Doxycycline also may be prescribed. The durations of prophylaxis and treatment generally are 3 to 5 and 10 to 14 days, respectively.3... 

Patients with animal bite wounds may require rabies prophylaxis.43,44 If the bite is from a bat, a wild animal, a domestic animal that has or is suspected to have rabies, or an unavailable animal, the patient should receive rabies immune globulin and vaccine immediately.45... 

Many bite wounds can be treated on an outpatient basis with amoxidllin-davulanic acid. 

The role of antimicrobials for noninfected dog bite wounds remains controversial because only 20% of wounds become infected. Antibiotic recommendations for empiric treatment include a 3- to 5-day course of therapy. Amoxicillin-clavulanic acid is commonly recommended for oral outpatient therapy. Alternative agents include doxycycline, or the combination of penicillin VK and dicloxaciHin. 

Management of bite wounds consists of aggressive irrigation and topical wound dressing, surgical debridement, and immobilization of the affected area. Primary closure for human bites is not generally recommended. Tetanus toxoid and antitoxin may be indicated. 

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