Bite Injuries: Human Bite

A 1-year-old girl was noted to have abrasions on the left cheek when she was picked up by her mother from a day-care center. The day-care provider reported that the girl had been bitten on the cheek by a 3-year-old boy during rough play. Her immunization status for tetanus was up-to-date.

The girl had parabolic-shaped marks on the left cheek that conformed to the shape of a human dental arch. The wound was irrigated with copious amounts of normal saline. The abrasion was no longer evident when the child was reassessed 10 days later.

Human bites are common among toddlers during aggressive play.¹ In older children and adolescents, bites might be sustained during a fight, most commonly when a clenched fist strikes the teeth of an opponent.¹ Other causes include child abuse, seizure, self-mutilation (Lesch-Nyhan syndrome), sexual assault, and sexual activity. In some cultures, when a child stops breathing, he or she is bitten in an attempt to stimulate breathing.²

Most human bite injuries occur on the face and upper extremities. These injuries might present as transient indentation marks, abrasions, puncture wounds, contusions, or lacerations.¹

The human oral flora contains multiple species of aerobic and anaerobic bacteria, and human bite wounds have a reputation for severe infection. The most frequently isolated aerobic bacteria are Staphylococcus aureus,Streptococcus species, Corynebacterium species, Haemophilus influenzae, and Eikenella corrodens.^3,4 The most frequently isolated anaerobic bacteria are Bacteroides,Veillonella, Prevotella, Porphyromonas, and Clostridium species.³ The rate of infection in children is only 10%, since most accidental bites in children are superficial injuries.^1,3 In contrast, approximately 20% to 50% of human bite wounds in adults become infected.³ Human bites have been implicated in the transmission of herpes simplex and hepatitis B and C.⁵

All bite wounds require meticulous cleaning and irrigation with copious amounts of normal saline. Devitalized tissue needs to be debrided. Antibiotic prophylaxis is not indicated for superficial wounds in children, since the majority recover uneventfully.¹ However, antibiotic prophylaxis is recommended for wounds on the hand--particularly clenched fist injuries, wounds that are deep or that contain devitalized tissue, and wounds in immunocompromised persons.¹

Antibiotic therapy is indicated for an obviously infected wound. Oral amoxicillin-clavulanic acid is usually effective. For children who are allergic to penicillin, clindamycin plus trimethoprim-sulfamethoxazole is an alternative therapy.

(Case and photograph courtesy of Alexander K. C. Leung, MD.)

REFERENCES:1. Leung AK, Robson WL. Human bites in children. Pediatr Emerg Care. 1992;8:255-257.
2. Leung AK. Pseudo-abusive human bite marks in a Chinese infant. Injury. 1985;16:503-504.
3. Smith PF, Meadowcroft AM, May DB. Treating mammalian bite wounds. J Clin Pharm Ther. 2000; 25:85-99.
4. Griego RD, Rosen T, Orengo IF, et al. Dog, cat, and human bites: a review. J Am Acad Dermatol. 1995;33:1019-1029.
5. Stefanopoulos P, Karabouta Z, Bisbinas I, et al. Animal and human bites: evaluation and management. Acta Orthop Belg. 2004;70:1-10.