Prophylactic Use of Antibiotics for Through and Through Lacerations of the Lip

Facial lacerations are commonly encountered problem in trauma and emergency room patients. Soft tissue trauma of the face can cause significant psychological impact. Wound care and the need to minimize scarring is particularly important in this region. There have been many studies evaluating the management of soft tissue injuries in general. For example, simple lacerations of the hand do not benefit from antibiotic therapy. The need for antibiotics for full thickness lacerations of the lip, however, has received little attention. Full thickness lacerations of the lip are defined as wounds that violate the mucosa, underlying muscle and skin (i.e through-and through lacerations). These oral-cutaneous injuries constitute a unique type of injury in that the laceration exposes the skin and underlying soft tissue to microbes of the oral pharynx that are normally encountered only by intact oral mucosa. This represents a uniquely different flora from that typically seen in simple skin lacerations. Because these are contaminated wound, there may be an increased risk for infection and an increased need for prophylactic antibiotics. Currently, there is no consensus on the prophylactic treatment of oral-cutaneous wounds with many physicians prescribing oral antibiotics, others utilizing topical antibacterials, and still others treating with local wound care.

A review of the literature found only four original articles addressing the topic of oral antibiotic prophylaxis. Two of these four original articles suffer serious methodological flaws. The first, published in 1965, was a prospective observational study which was neither blinded, nor specified the type or duration of antibiotic therapy. Despite these flaws, the study demonstrated a non-significant trend toward benefit with antibiotics. Of interest, the author noted all wounds older than 24 hours not treated with antibiotics became infected.

The second article, published in 1970 by Paterson et. was a prospective randomized trial, though the type and duration of antibiotic treatment in the intervention arm was left to the discretion of the treating clinician. The author combined both mucosal only oral lacerations and oral-cutaneous wounds. Wound infection was deemed to be present in 18.5% of patients treated with antibiotics versus 4.3% of those receiving no treatment (RR = 4.32, 95% CI = 1.30 to 14.31). None of the patients with mucosa-only wounds developed wound infections; all infections were seen in patients with "through-and-through" lacerations. Despite this, the authors concluded that the role of prophylactic antibiotics is questionable in preventing local infection.

The third article was a prospective, randomized study in the pediatric population evaluating all intra-oral lacerations. In this study 4.3% of patients treated with prophylactic penicillin had evidence of wound infection at follow-up, versus 8.5% of patients in the control arm (RR = 0.51, 95% CI = 0.10 to 2.65). The authors conclude that given the low background rate of infection in this study (8.5%), their study was markedly underpowered, and severely limited their ability to make any conclusions regarding the efficacy of prophylactic antibiotics.

Finally, in 1989, Steele et al. randomized 62 adult patients presenting within 24 hours of injury to a single emergency department with full-thickness intraoral or "through-and-through" lacerations to either treatment with oral antibiotics (penicillin VK for 5 days) or placebo therapy. Among patients treated with penicillin prophylaxis, 6.7% developed wound infection versus 18.8% in the placebo group (RR = 0.36, 95% CI = 0.08 to 1.63). In a subgroup analysis of patients who were perfectly compliant with therapy by pill counts, there were no infections in the penicillin arm versus 17.9% in the placebo arm (p = 0.054 using two-tailed Fisher exact test). The authors alternatively reported this as a statistically significant finding, using a one-tailed Fisher exact test, which yields a p value of 0.027. Furthermore, in subgroup analysis of "through-and-though" lacerations, 7% (1 out of 14) versus 27% (4 out of 15) of patients developed wound infection in the treatment and placebo groups, respectively (RR = 0.27, 95% CI = 0.03 to 2.12). Overall the authors conclude that while they cannot conclusively recommend prophylactic penicillin for adults with intraoral lacerations treated within 24 hours of injury, though there may be a trend towards benefit 9. They also suggest that patients with "through-and-through" wounds may benefit proportionally more from prophylaxis.

Despite the authors' inability to make conclusive recommendations from the available data, many textbooks cite these references and recommend the routine use of antibiotics for oral-cutaneous wounds. Many other text books, on the other hand, do not address this topic at all. Our study aims to answer the question of whether or not antibiotics reduce wound infection rates in through-and-through lacerations of the lip with a dedicated antibiotic regimen evaluated prospectively.

The type of antibiotic used to prophylactically treat oral-cutaneous wounds also remains controversial among clinicians. Previous studies have utilized penicillin V K. Penicillin, however, does not fully cover the flora typically cultured in infected oral-cutaneous wounds. Cephalexin is well described in the literature as an appropriate choice for oropharyngeal infections and has appropriate skin flora coverage, thereby, making it an ideal antibiotic for the prophylaxis of oral-cutaneous wounds.

Current practice concerning the use of antibiotics for oral-cutaneous wounds varies greatly. Many textbooks either do not address the topic or cite inconclusive evidence. A thorough search of the literature revealed only four original articles. No article was able to produce significant results and the trends and recommendations were mixed. Currently, there is no consensus regarding the treatment of oral cutaneous wounds and patients are treated with oral antibiotics, or local wound care depending on the treating physician's preference. It is important to determine the best treatment protocol for these unique wounds.