How Do You Treat Mammalian Bites?

Patient Presentation
The mother of a 2.5-year-old male calls because her son bit another child at daycare today and the bitten child’s family is threatening to call the state agency to have her son taken out of the daycare and to have the daycare closed down.
The daycare provider is not worried about the incident but had to contact the mother because of the possible state agency action. The mother states that her son bit the same child last week also. Both incidents were witnessed by the childcare provider who says that the children were arguing over a toy and the childcare provider could not get to the children to intervene in time.
The son has bitten his younger brother in the recent past, again because of a toy.
The past medical history reveals normal development and growth of the boy.
The diagnosis of normal toddler behavior was made. The physician discussed that biting is a common, normal behavior for toddlers that can be caused by a number of factors including frustration and the inability to use language or other means to solve the problem.
The mother was told to monitor the behavior as this appeared to be a new behavior. She was told to try to prevent these situations by offering a variety of toys and to try to intervene early if a potential conflict is developing. She was also instructed to try to remain calm and model other forms of conflict management such as using words or ignoring.
She was told that these methods would not work right away but overtime would help show her son other ways to help solve problems.

Occasional acts of anger, aggression or biting, especially during temper tantrums, are a normal part of toddler and preschooler behavior. These children do not have the self-control to express their anger in a less dangerous manner. Most children only bite when they are angry and provoked.
Being tired, hungry, and overstressed often heightens the frustrustration and anger. Some children can bite because of extreme emotions that they cannot control (i.e. they are so happy to see someone that they bite them).
Most children can be distracted or consoled and often quickly forget their anger. Concerning symptoms include:

  • Biting occurs daily for more than 3-6 months
  • Frequent rages where the child attacks others, animals or himself
  • Preschoolers who lash out for no apparent reason or who feel no remorse or empathy for the other child
  • Concern by an adult that the child will seriously injury himself or another child
  • A child is barred from play by neighbors or school

Parents should be instructed to supervise their children and not interfere in minor disagreements as this allows the children to try to solve the conflict on their own. Parents must intervene when there is a physical threat which continues.
Parents should also be told reprimand the child immediately for breaking important rules (e.g. no hitting, biting, running into the street) as the child so the child will understand what he has done wrong. Modeling and teaching other non-violent forms of conflict resolution including saying “NO” in a firm voice, ignoring, walking away, or asking a grown-up for help are good methods. Praising the child for using these non-violent strategies also reinforces these preferred behaviors.

Mammalian bites occur in 1-5 millon cases annually. Most mammalian bites are due to dogs (80-90%), cats (5-10%), and humans (2-3%).

Mammals can inflect a broad spectrum of injuries including scratches, abrasions, contusions, punctures, and lacerations, or combinations of these injuries. Complications occur such as cellulitis, deep compartment syndrome, tendinitis, osteomyelitis and septic arthritis.

Dog bites frequently occur with large family dogs. Half of the bites are unprovoked. They occur in males > females often in the upper extremities, but children < 5 years old often have head and neck injuries. The rate of infection is 15-20%.

Cat bites occur in household provoked cats. They occur in females > males, mainly in the upper extremities and have a rate of infection of 50%. Puncture wounds are common.

Human bites are a leading cause of injuries in daycare centers. They appear as semi-circular, erythematous or bruised areas often over the face, upper extremities or trunk. The intercanine distance for a child bite is < 2.5 cm. If it is > 3 cm then the bite is likely from an adult and child abuse must be considered.
Humans bites also often occur when an open mouth and teeth strike a clenched fist.

The organisms that complicate dog and cat bites include: Pasteurella species, Staphylococcus aureus, streptococci, anaerobes, Capnocytophagea species, Moraxella species, Corynebacterium species, and Neisseria species. Cat bites have an especially high rate of Pasteurella multocida contaminating its wounds (50%).

The organisms that complicate humans bites include: streptococci, Staphylococcus aureus, Eikenella corrodens, and anaerobes.

Learning Point
Treatment for mammalian bites includes:

  • Cleaning the wound – Sponge away obvious debris and then irrigate with copious amounts of normal saline by high pressure syringe irrigation. Puncture wounds should not be irrigated because of the potential to actually drive the organisms deeper into the wound.
  • Wound culture – should be done if there are early signs of infection, an immuncompromised patient or if an animal bite is more than 8 hours old.
  • Operative debridement of devitalized tissue is important. Bites to the hand should be considered for debridement. Cranial bites may need radiographs to look for free air in the skull.
  • Wound closure – is indicated for non-puncture bite wounds less than 8 hours old. Immobilization may be necessary for large wounds.
  • Vaccination for Tetanus, Rabies and Hepatitis B should be evaluated. HIV risk should be also evaluated and treated by CDC guidelines for non-occupational exposure to HIV ( see also Case from 2/14/05). Intact or nonintact skin or percutaneous contact with saliva is usually considered a negligible risk for HIV transmission.
  • All significant wounds should be rechecked in 24-48 hours.
  • Antibiotic prophylaxis should be initiated for all human bites and for all but the most trivial dog or cat bites. Indications include moderate to severe bite wounds especially if crush injury or edema is present, puncture wounds, an immunocompromised patient or bites in the following locations: face, hand, foot, genitalita.
    First line oral antibiotic for dogs/cat/human bites is amoxicillin/clavulante for non-penicillin allergic patients.

Questions for Further Discussion
1. Should antimocrobial or antiinfective solutions be added to the saline solution for irrigation?
2. What are the potential complications of rodent bites?
3. What is the preferred antibiotic treatment for penicillin-allergic patients?

Related Cases

ACGME Competencies Highlighted by Case

  • Patient Care
    1. When interacting with patients and their families, the health care professional communicates effecively and demonstrates caring and respectful behaviors.
    4. Patient management plans are developed and carried out.

  • Medical Knowledge
    10. An investigatory and analytic thinking approach to the clinical situation is demonstrated.
    11. Basic and clinically supportive sciences appropriate to their discipline are known and applied.

  • Interpersonal and Communication Skills
    17. A therapeutic and ethically sound relationship with patients is created and sustained.

  • Systems Based Practice
    24. Cost-effective health care and resource allocation that does not compromise quality of care is practiced.

    To Learn More
    To view pediatric review articles on this topic from the past year check PubMed.

    To view current news articles on this topic check Google News.

    Fleisher GR, Ludwig S. Synopsis of Pediatric Emergency Medicine. Williams and Wilkins. Baltimore, MD. 1996:473-475.

    American Academy of Pediatrics. Bite Wounds, In Pickering LD, ed. Red Book: 2003 Report of the Committee on Infectious Diseases. 26th edit. Elk Grove Village, IL: American Academy of Pediatrics; 2003;182-186.

    Shelov, Steven P. Caring for Your Baby and Young Child Birth to Age 5. Bantam Books. New York, NY. 1997:495-497.

    Donna M. D’Alessandro, MD
    Associate Professor of Pediatrics, Children’s Hospital of Iowa

    November 14, 2005