Bites

Last updated 20.09.12

 

Index

 

-  Red Back Spider Bite

-  Snake Bites

 

Definition

-  Wound sustained from animal/human bite

 

Features

-  Common presentation

-  Dog Bites

-  Animal usually known to pt

-  In children usually head or neck

-  Adults typically dominant hand

-  Cat Bites

-  Usually provoked

-  Typically upper extremity or face

-  Human Bites

-  Paeds: must exlucde NAI esp if intercanine distance >3cm

-  +/- self inflicted: pysch

-  Clenched fist injury from punch to face on MCP joints

-   3rd & 4th MCPs on dominant hand

-  Genitals or breast ?sexual abuse

-  Unusual animal bites

-  May need to consider other micro-organisms

-  May be initially manged as per cat bites

 

Associated S/S

-  Bite marks

-  Animal vs human

-  ?NAI esp if intercanine distance >3cm

-  Open wound

-  Neurovascular or tendon injury

-  Wound infection

-  12-24hrs fever, erythema, swelling ?pasturella multocida (cat or dog)

 

Complications

-  Wound infection

-  Cellulitis

-  Abscess

-  Septic arthritis

-  Osteomyelitis

-  Bacteraemia or Sepsis

 

Micro-Organisms

-  From oral flora from bite + human skin flora at wound site

-  Animal

-  Pasteurella

-  Staphylcocci

-  Streptococci

-  Anaerobic bacteria

-  Bartonella henselae (cat scratch disease)

-  Rabies virus

-  Human

-  Eikenella corrodens

-  Group A strep

-  Anaerobes

 

Ix

-  +/- Blood cultures prior to Abx

-  +/- FBE: WBC elevation

-  +/- CRP, ESR

-  +/- Wound swab MCS

-  Only useful if infected

-  X-ray

-  Esp if near joint

-  Fracture

-  Foreign body

-  Osteomyelitis

-  +/- US

-  Abscess formation

-  Foreign body

 

Mx

-  Analgesia + anaesthesia (GA or LA)

-  Irrigation

-  If puncture wound soak for 15min in antiseptic solution

-  Debridement (+/- surgery)

-  Exploration: tendon, nerve, vessel injury

-  Repair

-  Secondary intention

-   Most human & cat bites or infected wounds

-   Copious irrigation, dressings (NS gauze BD/TDS) & regular examination

-  Primary closure

-   If uninfected, <12hrs old, not on hand or foot

-   Usually not if crush or puncture wounds

-   Delayed primary closure >72hrs

-   Copious irrigation, dressings (NS gauze BD/TDS) & regular examination

-  Dressings

-  Antibiotic prophylaxis 3-5 days

-  Given as soon as possible post wound +/- IV first dose

-  Indicated if

-   Deep puncture wounds (esp cat bites)

-   Crush injury

-   Venous compromise

-   Close proximity to joint

-   Wounds repaired w primary closure

-  Tetanus

-  All bites/wounds that break skin are prone to tetanus

-  ADT 0.5ml IM

-  If wound infection

-  Remove sutues

-  Wound swab MCS

-  +/- BC

-  +/- debridement, exploration, incision, drainage

-  Antibiotics 10-14 days

-  Tazosin 4.5g (kids 125mg/kg/dose) IV 8/24

-  OR Timentin 3.2g (kids 50mg/kg/dose) IV 4/24

-  OR Ceftriaxone 1g IV Daily

-   PLUS Metronidazole 500mg IV 8/24

-  May change to PO Augmentin DF 875/125mg (20mg/kg/dose) PO BD

-  Considerations

-  Rabies: although not common in Australia

-  HBV: if human biter Hep B positive --> Hep B Ig + Hep B vaccine

-  PTSD: esp in children

 

 

 

References

 

Upto Date: Initial Management of Animal & Human Bites: 30/06/2009

eTG: Skin & Soft Tissue Infections: bites & clenched fist injuries: June 2010