A Rare Presentation of Donkey Bites Involving the Cheek and Ear: A Case Report and Literature Review

Although animal bites account for a fair number of emergency department visits, donkey bites account for a very limited proportion. A 12-year-old boy presented to our department with a severe donkey bite involving his face. The injury included his left cheek with a laceration of the left ear cartilage. The examination revealed no serious morbidity (no vascular or nerve involvement). The patient received prophylactic antibiotics and anti-rabies/anti-tetanus vaccination. The wound was cleaned thoroughly with copious irrigation. Afterward, the patient underwent surgery to correct the defect in the cheek using a rotational advancement cervicofacial flap, while the penetrated ear cartilage was repaired and the skin margins were approximated and sutured. During the follow-up period, no complications were observed and the functional and cosmetic outcomes were satisfactory. Donkey bites are rarely encountered and they can result in different presentations and morbidities/outcomes. It is suggested that the timing from the bite injury to presentation, the stage/extent of the bite, the use of anti-tetanus and anti-rabies vaccines, and the prophylactic use of antibiotics may play a role in determining the outcomes and/or complications of donkey bites.


Introduction
Mammalian bites account for 1% of all visits to the emergency room, making bite wounds rather common. Dog, cat, and human bites are increasingly common and are a significant cause of morbidity and mortality [1]. Based on a previous report, around 50% of Americans will experience an animal or human bite at least once during their life span, and 45% of children had been bitten at some point [2]. An animal bite could have an impact on any part of the human body, including the upper extremity [3], lower extremity [4], thorax [5], female breast [6], and genitalia [7]. Frequently, the head and neck area is involved [2]. Animal bites are a significant issue in health care and frequently result in trauma to the hands and faces of young children.
However, donkey bite injuries are fairly uncommon, despite having the potential to cause serious injuries and complications [8]. The associated morbidity and mortality are widely variable depending on the location and extent of the bite; however, bite-associated outcomes are frequently worse in horse bites than in donkey bites. Particularly, maxillo-facial trauma caused by donkey bites is uncommon with more than 75% of the facial bites affecting the lips, nose, or cheeks [9]. It can result in serious, and sometimes fatal, facial injuries with profound functional and cosmetic consequences [9].
The management of animal bites includes both local wounds and systemic considerations [1]. It can be divided into general and specified approaches [1]. The general approach includes a thorough examination and proper cleaning of the wound. Meanwhile, the specified approach depends mainly on the site and extent of the bite as well as associated injuries involving the adjacent nerves or arteries. Antibiotic consideration is an essential step in the management process to prevent wound infection, which is a serious complication with potentially negative functional and/or cosmetic outcomes.
Even though donkey bites may resemble other mammalian bites in terms of clinical presentation, there are specific features that distinguish these bites. Donkey bites may be circular or oblong in shape, with a diameter ranging from a few millimeters to several centimeters. They may also have a puncture wound at the center. Furthermore, they can be quite powerful and can result in deep tissue damage. Unlike other animal bites, such as dog bites, which tend to be quick and sudden, donkey bites are often sustained over a longer period, which can result in more extensive injuries [10].
Here, we present a case of a donkey bite-associated cheek and ear laceration with special emphasis on its presentation, management, and postoperative outcomes.

Case Presentation
A 12-year-old boy was admitted to the Emergency Department at Lebanese Hospital Geitawi, Beirut, Lebanon. One hour after the incident, the patient presented with a severe donkey bite involving the face, resulting in left cheek and ear lacerations ( Figure 1). The patient in this case provoked the donkey by trying to touch it without the owner's permission. The donkey, as a result, became agitated and bit the patient. It is noteworthy that the patient consented to the use of his charts and images for the purposes of this report.

FIGURE 1: Post-injury wound (one hour after the bite), showing bite marks on the left cheek and ear
The patient's medical history revealed no significant findings, and he was completely healthy prior to the incident. A detailed physical examination was carried out, showing the following findings: no intra-oral communication with the cheek laceration, inability to elevate the left angle of the mouth in a superolateral direction, and inability to smile. Meanwhile, the patient was able to show his teeth, blow out his cheek, whistle, close his eyes completely against resistance, and wrinkle his forehead. Upon examining the patient's left ear, we found lacerations of the external part of the ear (on the helix and anti-helix) while the cartilage was penetrated. However, his injury did not affect his hearing capacity; both ears had the same capacity.
The injury was then managed immediately and appropriately. Copious irrigation and proper cleansing were done using normal saline. Afterward, the patient received antibiotics (ceftriaxone 1g once daily and clindamycin 600mg twice daily) as well as tetanus and rabies prophylaxis. The patient was then taken to the operating room, where proper cleaning of the wound was carried out under general anesthesia. Exploration of the defect in the left cheek was done (Figure 2), revealing a partial loss of the zygomaticus major muscle (mainly at its insertion site); however, the facial nerve was completely intact at this point. Stensen's duct was intubated and found intact. In order to cover the site of the defect, a rotational advancement cervicofacial cheek flap (Mustarde flap) was done. Similarly, the penetration of the ear cartilage was repaired and then the skin margins were sutured ( Figure 3).

Discussion
To date, there are no accurate statistics regarding the incidence or rate of animal bites, particularly donkey bites, around the globe. However, a recent chart-review study in Turkey reported an incidence of horse and donkey bites of 7.8 per 100,000 individuals. Upon reviewing 445,698 records over three years, only 36 cases of donkey and horse bites combined were reported; of those only 26 cases were specific to donkey bites [10].
Despite being a rare event, the presentation of donkey bite can vary substantially, depending on numerous factors, including age and the site and extent of the bite ( Table 1). Upon reviewing the literature, we found that cases of donkey bites were more commonly reported in males (17 out of 20 cases) and in places where donkeys were raised as domestic animals (nine out of 20 cases), and this, in turn, can potentially result in an increased likelihood of bites secondary to the prolonged exposure to animals. The age of patients can play an important role in the occurrence of these incidents. Cases of animal bites have only been reported in the extremes of age (very young or very old). Among the 20 cases reported in the literature, the age ranged from five [11] to 76 [12]. This occurrence of donkey bites in these cases is, hypothetically, justifiable given their inability to defend themselves from any attacks or for doing something that can provoke these animals [10].   [9,[12][13][14], the neck (six cases) [15][16][17], extremities (six cases) [13,16,18,19], the ear (one case) [13], the scalp (three cases) [11] or the penis (two cases) [19,20]. Our case came to the emergency department with rather a rare presentation involving the cheek and ear, which are rarely reported in the literature. The presentation and associated morbidity are dependent on the classification of the injury. The most commonly used classification system is Lackmann's classification of bite injuries ( Table 2) [11]. Our case presented with stage three, a deep wound involving the muscles with the presence of a defect that was observed upon exploration. The stage of donkey bites in the literature have varied widely, and there are cases where bone involvement/fracture [18] or organ amputation [19,20] have been reported. Furthermore, three cases have been found dead on examination following donkey bites [14,15,17]. The outcomes and associated morbidity of the donkey bite are linked with the stage of the bite injury.  The management of donkey bites is dependent upon the site and extent of the bite. However, generally, the management of such bites is done in two steps: general wound cleaning and irrigation and then specific management (surgery if needed) to correct any associated defects. The detailed management protocol of such cases in the literature is summarized in Table 3. The aim of treatment is to reach optimum functional as well as cosmetic outcomes. The timing from bite injury to presentation, the use of anti-tetanus and antirabies vaccines, and the use of prophylactic antibiotics might aid or quicken the healing process ( Table 3).

Staging Extent of Injury
Post-management complications are not rare, and they may range from simple minor complications (such as minor scars) [16] to moderate complications (extensive scarring and/or infection) [9] to serious complications (such as death probably due to fat embolization) [13]. In our case, the injury was healed satisfactorily without any complications. This might be related to the proper management (surgical exploration, antibiotic use, and rabies and tetanus vaccination) given to the patient in a timely manner upon presenting within one hour of the bite injury incident. It has been observed in the literature that donkey bites involving the upper extremity or the digits ended in a purulent infection and tissue necrosis [8,16]. In these cases, no prophylactic antibiotic was administered, and patients were not vaccinated against rabies and tetanus upon presentation [8,16]. In terms of cosmetic outcomes, the timing from the bite injury to presentation has been hypothesized to play a role. In the two cases reported by Tiemdjo, et al., donkey bites involved their legs [18]. In one case, the patient retained his functional capacity with normal movement and the wound healed completely. Meanwhile, in the second case, the healing process of the bone took longer, the patient regained his normal range of motion within 270 days, and the wound healing was of poor quality. This could be because of the timing from the bite to presentation and appropriate intervention; in the first case the patient presented within two hours, while in the second case presented within two days after the bite.

Conclusions
Donkey bites are rarely encountered and they can result in different presentations and morbidities/outcomes. It is suggested that the timing from the bite injury to presentation, the stage/extent of the bite, the use of anti-tetanus and anti-rabies vaccines, and the prophylactic use of antibiotics may play a role in determining the outcomes and/or complications of donkey bites. Therefore, prompt and appropriate medical attention along with proper wound management are essential in minimizing the potential risks associated with donkey bites.

Additional Information Disclosures
Human subjects: Consent was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work.