Management of Facial Bite Wounds

Wound characteristics

Animal bites can result in three main types of soft tissue trauma, namely punctures, lacerations, and avulsions, with or without an actual tissue defect.14, 23, 29, 30, 31 The typical dog bite results in a combination of torn tissues and adjacent punctures, the so-called “hole-and-tear” effect (Fig. 1).³² Some degree of crush injury is also present in most bite wounds, including those from humans, due to the dynamics of the bite.27, 33 Dog bites of the face are located mostly on the lips, nose,

Overview of microbiology

The importance of the indigenous oral bacteria in bite-wound infections is substantiated by the high isolation rates (>50% of cases) of Pasteurella spp from dog and cat bites,33, 48, 49 and viridans streptococci, especially Streptococcus anginosus, from human bites.³⁰ There are also corresponding figures for oral anaerobes, including Fusobacterium nucleatum, Bacteroides, Prevotella, and Porphyromonas spp.12, 30, 49 It should be appreciated, however, that almost any oral organism can become a

Risk factors for wound infection

Facial bite wounds generally display low infection rates, commonly attributed to the rich blood supply of the area.2, 18, 55, 61 Dog bites on the face are usually considered to be at moderate risk for infection when compared with other types of mammalian bites,³³ especially those inflicted by cats,6, 12 which harbor the more toxic P multocida organisms.⁵² Furthermore, dog-bite wounds seen within 3 hours of injury rarely contain more than 10⁵ bacteria per gram of tissue, while human bites

Clinical evaluation

With extensive head or neck injury, life-preserving emergency procedures take precedence;11, 22, 27, 28, 46, 59, 70, 72 cervical immobilization should also be considered.²² Otherwise, there is time to obtain the necessary information about the incident as well as about the general condition of the patient.44, 70

When there is a possibility of involvement of underlying specialized structures, early diagnosis is essential. Eyelid lacerations require careful evaluation to rule out penetrating

Local wound care

As with any laceration, the mainstays of wound care are irrigation and removal of any necrotic tissue.58, 72, 75 However, common practices, such as cleansing with soap or scrubbing,44, 58 are best reserved for high-risk wounds. Irrigation is essential in preventing infection because it removes debris and microorganisms;59, 61, 71, 72, 75, 83, 84 wounds difficult to irrigate thoroughly, such as punctures, are twice as likely to become infected.⁸⁵ Manual irrigation with a 19-gauge catheter on a

Surgical treatment

Primary wound closure is the treatment of choice for all uninfected facial bite lacerations seen within 24 hours, as well as for many avulsion injuries, because this obtains the most favorable esthetic result.12, 16, 17, 18, 26, 27, 28, 34, 35, 36, 39, 40, 41, 42, 43, 59, 64, 75, 91 Subcutaneous sutures should be used sparingly, however, because they can act as foreign bodies and precipitate infection.27, 59 By contrast, deep puncture wounds should be left open, particularly when inflicted by

Antibiotic treatment

Antibiotic administration for bite wounds can be either prophylactic or therapeutic.12, 101 In the presence of established infection or any underlying predisposing condition, antibiotic therapy is indicated. However, it remains unclear whether otherwise healthy patients with fresh clinically uninfected wounds benefit from prophylactic antibiotic administration.18, 55, 101 Even in these cases, however, antibiotic therapy may actually be therapeutic if enough time has elapsed for bacterial

Discussion

Undoubtedly, high-pressure irrigation has a crucial role in the conversion of the contaminated (or even dirty) bite wound into a clean-contaminated environment suitable for subsequent primary closure. Routine use of normal saline is recommended on the premise that emphasis should be placed on the mechanical effect rather than on any antibacterial activity of a more potent solution, which on such a complex wound would be a potential irritant or at best only temporarily effective (see Box 2). The

Summary

Primary closure is the standard of care for most facial bite wounds, preceded by proper wound irrigation and debridement, where indicated. Administration of antibiotics, preferably on admission, is advisable for all injuries requiring suturing; clean linear lacerations, treated within 3 hours after injury, are possible exceptions. Depending on the clinical appearance of the lesion, patients presenting beyond the first 24 hours should be treated with delayed closure. This option should

Acknowledgments

The senior author wishes to thank Professor Michael L. Callaham, MD, for his kind suggestions, and Miss Martha Petromihelaki, for her constant help with the literature search.