Mammalian bites – Emergency management in children

Purpose

This document provides clinical guidance for all staff involved in the care and management of a child presenting to an Emergency Department (ED) following a mammalian bite in Queensland.

This guideline has been developed by senior ED clinicians, with input from infectious diseases, plastics and pharmacy teams, Queensland Children’s Hospital, Brisbane.

It has been endorsed for use across Queensland by the Queensland Emergency Care of Children Working Group in partnership with the Queensland Emergency Department Strategic Advisory Panel and the Healthcare Improvement Unit, Clinical Excellence Queensland.

Introduction

Australia has one of the highest rates of pet ownership in the world with 73% of households owning a pet.¹ Dog bites are the most common animal injury in children <4yrs of age, accounting for 61% of hospitlisations due to contact with an animal.² This is followed by cats (5-10%), humans (2-3%) and rodents (1%).^2,3

Risk factors for dog bites are male gender and younger age, with Children under 5yrs at highest risk of head and neck injuries.^{1,2,3,4,5,6,7}

Bite related injury can vary greatly depending on the animal’s characteristics and the anatomic location of the bite. Dog bites usually comprise of crush injuries, lacerations and abrasions.
Cat bite injuries are typically a puncture wound that could seem minimal at the skin surface but can penetrate deeper layers including into joints.¹ Cat bites tend to have a higher incidence of infection due to depth of tissue penetration, and the microbes of the oral cavity.⁴

Psychological trauma, including post-traumatic stress disorder, is very common in children who have experienced dog attacks.^3,8 This can result in new concerning behaviours occurring in children such as nightmares, avoidance behaviour and increased behavioural difficulties.⁹ In one study it was found new behaviours occurred in more than 70% of dog bite cases.¹⁰

Infection rates of bite wounds can vary depending on the animal’s oral flora, the environment, or the host skin flora. Different mammalian species have characteristic oral flora, but all infections caused by mammalian bites should be considered to be polymicrobial.^3,5,11 The chance of a bite site being infected varies by species – human and cat bites are the more likely to be infected.^3,4,5,12

• Predominantly cats and dogs:
  • Pasteurella sp. should be considered in rapidly progressive skin and soft tissue infection following mammalian bites. The incubation period for Pasteurella multocida infection is one to three days.^{5,11,13,14,15}
  • Capnocytophaga canimorsus can cause bacteremia and fatal sepsis after animal bites, especially in patients with asplenia or immunocompromising conditions. The incubation period for C. canimorsus infection is one to three days.^5,11,15
  • Bartonella henselae may be transmitted via the bite of an infected cat; other forms of transmission include cat scratches and contact with cat saliva via broken skin or mucosal surfaces. The incubation period for B. henselae infection is 7 to 14 days.⁵
• Possum
  • Francisella tularensis may be transmitted by bites/scratches and cause Tularaemia disease. Symptoms develop day 3-5 and include are high fever, a skin ulcer at the site of the bite or skin exposure, and swelling of the nearby lymph glands chills, fatigue, general body aches, headache and nausea.^5,16
• Macaque Monkeys
  • Macacine alphaherpesvirus 1 transmitted by infected macaque monkeys can cause severe CNS disease including encephalitis.
• Rats
  • Rat bite fever (caused by Streptobacillus moniliformis or Spirillum minus) should be considered in a child presenting with fever, rash and arthritis 4 to 10 days following a rodent bite.⁵

• Horses (not bite related)
  • Hendra Virus is known to have infected 7 people after high levels of exposure to infected horses. It should be considered in a child with a influenza-like illness 5 -21 days post exposure to a sick horse.¹⁷

• Humans
  • Clenched fist injuries (“fight bites”) are considered the most severe human bite injuries and result from the patient striking another person’s teeth. They usually occur at the metacarpophalangeal joints of the dominant hand of the patient. In these cases, there is a higher risk for septic arthritis and osteomyelitis.^3,4,5
  • Human immunodeficiency virus (HIV) and Hepatitis B virus (HBV) can be transmitted following a human bite.^18,19 (For elaboration see the CHQ-GDL-65664 Post-Exposure Prophylaxis for HIV [PDF 524.41 KB] and contact the Public Health and the Infection Disease consultant on service to discuss any suspected cases). Risk of HIV transmission is low.^19,20
• Bats
  • Mammalian bites in locations with endemic rabies (not including Australia) can transmit rabies and bat bites/scratches within Australia can transmit the Australian bat lyssavirus (similar to rabies virus). Three patients have died due to Australian bat lyssavirus infection. (For elaboration see the CHQ-GDL-00719 Management of children presenting with potential Lyssavirus (rabies) exposures - Emergency Management in Children [PDF 554.21 KB] and contact Infection Disease consultant on service to discuss suspected cases)

Assessment

The primary aim of the assessment is to identify children who need urgent management.

History

Include specific questioning on:

• Circumstances of the bite:
  • Animal species
  • Timing
  • Geographical location
  • Circumstances surround the event and any child safety concerns
• Immunisation status (including tetanus [PDF 668.37 KB], rabies [PDF 554.21 KB], hepatitis)
• Immunosuppression
• Other medical comorbidities that may limit wound healing and predispose to higher rates of infection such as diabetes and immunosuppression.

Examination

• Careful physical examination is needed including exploration of apparently minor injuries.
• Assess the wound location and severity, degree of penetration of bone or joint, tendon function and neurovascular function.

Explore the wound (local or general anaesthetic if needed)

• Look for foreign bodies (e.g. animal teeth).

For late presentations, assess for established infection (e.g. pain, swelling, erythema or discharge from wound, significant pain on passive movement of nearby or affected joints).

Assess for wounds at high risk of infection

• Puncture and crush wounds
• Penetration of bone/joint/tendon/ligament/vascular structures
• Wounds of hands/feet/face or genitals
• Delayed presentation > 8 hours
• Cat bite wounds
• Water immersed wound infection [PDF 325.4 KB]
• Immune compromised patients (including asplenic children)

Investigations

Management

Any life-threatening injuries should be treated according to standard guidelines.

Wound management^3,5,21,22,23

Discuss with the patient and parents an appropriate anaesthetic for management of the wound; this may involve a field block with local anaesthetic, sedation, or a general anaesthetic if large debridement/wound closure is required, or if the wound is grossly infected.

• Remove any foreign bodies.
• Clean wound thoroughly with 0.9% normal saline. Use enough fluid to remove all visible dirt and foreign material (minimum is 50mL per 1cm wound).
• Open wounds should be irrigated with pouring copious fluids and non-viable tissue should be debrided.

Wound closure

General principles

Decisions regarding wound closure should be individualised, balancing:

• Risk of infection
• Cosmetic and functional outcomes
• Evidence is limited; recommendations are based largely on observational data and consensus guidelines

Avoid primary closure in:

• Delayed presentation (>24 hours)
• Clinical infection (erythema, purulence, increasing pain)
• High-risk wounds, including:
  • Puncture wounds (especially cat bites)
  • Crush injuries
  • Devitalised tissue
  • Bites to hands/feet
  • Immunocompromised patients

These wounds are typically managed with:

• Irrigation + debridement
• Delayed primary closure or healing by secondary intention

Consider primary closure in:

• Facial wounds
  • Rich vascular supply → lower infection risk
  • Strong cosmetic imperative
• Selected low-risk wounds, if:
  • Early presentation (<12–24 hours)
  • Adequately irrigated and debrided
  • No devitalised tissue

Key points for facial bites:

• Primary closure is recommended
• Infection risk is low (~1–5%) with appropriate management
• Management should include:
  • Copious irrigation + meticulous debridement (caution around unnecessarily excising normal tissue on face)
  • Consideration of prophylactic antibiotics
  • Plastic surgery input for complex wounds
• Patients/parents should be counselled regarding:
  • Small but real infection risk
  • Need for close follow-up

Complex bite wounds

• Elevate injured extremity for the first 2-3 days.
• Significant hand wounds can benefit from 3-5 days of immobilisation.
• A fracture associated with a bite should be managed as a compound fracture with IV antibiotic treatment and hospital/specialist referral.

Vaccinations/ postexposure prophylaxis

• For all bat bites or scratches, please refer to the Management of children presenting with potential Lyssavirus (rabies) exposures – Emergency Management in Children [PDF 554.21 KB]
• Tetanus vaccination and/or tetanus immunoglobulin, where indicated, should be administered according to the Tetanus Prophylaxis in Wound Management [PDF 668.37 KB]
• For human bites including clenched fist injuries consider hepatitis B if not immune and HIV prophylaxis [PDF 524.41 KB]. PEP is not currently recommended¹⁷ (if at high risk seek ID advice).

Antibiotic treatment^22,23

Antibiotic therapy is not required if the wounds are small, not involving deeper structures and present within 8 hours and can be adequately debrided and irrigated in the healthy individual.

Prophylactic treatment is indicated in wounds with high risk of infection that include:

• presentation to medical care is delayed by 8 hours or more
• the wound is a puncture wound that cannot be debrided adequately
• the wound is on the hands, feet or face
• the wound involves deeper tissues (eg bones, joints, tendons)
• the wound involves an open fracture
• the patient is immunocompromised (eg due to asplenia or immunosuppressive medications),
• the wound is a cat bite.
• For empiric antibiotic recommendations, refer to the CHQ-GDL-01202 CHQ Paediatric Antibiocard: Empirical Antibiotic Guidelines [PDF 705.34 KB]
  • If water-related/immersed wound infection, also refer to CHQ-GDL-63000 Management of Water-immersed Wound Infections in Children [PDF 325.4 KB] and contact Infection Management team for advice.
  • If open globe/penetrating eye injury, also refer to CHQ-GDL-01074 Acute management of Open Globe Injuries (penetrating eye injury) [PDF 426.05 KB] and contact Ophthalmology team for advice.
  • In patients presenting with sepsis/shock, follow the Paediatric sepsis pathway [PDF 4229.69 KB] recommendations and consult Infectious diseases specialist early.
• Use of topical antimicrobials are not recommended. Use sterile white soft paraffin to aid in healing.

Psychological impact

• Caregivers should be informed of the possible psychological impact and advised to see their GP if symptoms persist.
• Symptoms of psychological impact include nightmares, avoidance behaviour, increased behavioural difficulties, re-experiencing the event, hyperarousal (hypervigilance, anger, irritability), alterations in mood and thinking.^10,24

Reporting

• Brisbane Council responds to reports of dog attacks and aggressive dogs 24 hours a day, 7 days a week and can be reported by calling Council on 07 3403 8888.

Disposition

When to escalate care

Follow your local facility escalation protocols for children of concern. Transfer is recommended if the child requires care beyond the level of comfort of the treating hospital. Clinicians can contact the services outlined below to escalate the care of a paediatric patient.

Indications for referral

• Systemic signs of infection
• Refractory to oral antibiotics
• Multiple and severe injuries
• Involvement of joint/bone/nerve/tendon
• Wound requiring surgical intervention
• Significant hands, feet or facial bites
• Human bites with puncture wounds
• Immunocompromised host

Contact specialist teams, infectious diseases, plastics or ortho via CATCH depending on indication.

When to consider discharge from ED

Consider discharge in non-severe cases, systemically well children with no other indication for admission.

Follow-up

• In 24 to 48 hours by General Practitioner (GP) unless advised otherwise by a specialist.

When to consider admission

Admission should be considered in any case of:

• Systemic signs of infection
• Refractory to oral antibiotics
• Multiple and severe injuries
• Involvement of joint/bone/nerve/tendon

Related documents

Information for families

Recommendations for prevention

• Dogs and children: preventing child injuries
• Helping your child after a dog bite

Guidelines

• CHQ-GDL-01023 Tetanus Prophylaxis in Wound Management [PDF 668.37 KB]
• CHQ-GDL-00719 Management of children presenting with potential Lyssavirus (rabies) exposures - Emergency Management in Children [PDF 554.21 KB]
• CHQ-GDL-01202 CHQ Paediatric Antibiocard: Empirical Antibiotic Guidelines [PDF 705.34 KB]
• CHQ-GDL-63000 Management of Water-immersed Wound Infections in Children [PDF 325.4 KB]
• CHQ-GDL-01074 Acute management of Open Globe Injuries (penetrating eye injury) [PDF 426.05 KB]
• Queensland Statewide Paediatric Sepsis pathway [PDF 4229.69 KB]