Bites (Quiz 2) Flashcards
What are the most common animal bites?
- 1.Dogs: 85-90% of all animal bites
- 2.Cats: 5-10% of all animal bites
- 3.Humans: 3rd most common of all bites
Are dog bites typically provoked?
- >70% of dog bites: unprovoked & from dogs known to the victim
- Most dog bites are preventable
- Most deaths from bites are caused by dogs, particularly Rottweilers & Pit Bulls
- Surprisingly, dog bites to infants that result in death occur most commonly when infant is sleeping
Prevention of bites includes:
training, proper control of dogs, & education
Characteristics of abrasions
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- Superficial damage to skin
- Limited bleeding
- Lower risk of infection
Characteristics of crush injuries
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- Related to force of bite
- Dogs can exert 200-450 psi of pressure when they bite
- Open or closed wound
- Can injure muscle, bone, tendon
- Crush injuries usually contain devitalized tissue that should be debrided to help prevent infection
- Compression lacerations
- Irregular wound edges
- Severe crush injuries:
- Risk for rhabdomyolysis
- Neurovascular injury
- Assess distal to injury
Characteristics of puncture wounds
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- Result of trauma from sharp, pointy object (cat tooth/nail)
- Typically no excessive bleeding
- May be deep penetration
- Highest risk for infection
- ***Often wounds do not look very bad, and are already infected when parent brings child in
Characteristics of lacerations
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- Soft tissue tear
- May be very deep
- Often irregular edges
- Surrounding abrasion and bruising
- Bleeding may be heavy
- Often contaminated with bacteria and debris
- High risk for infection
Characteristics of avulsion
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- Skin or soft tissue is partially or completely torn away
- Most common on face: lips and ears
- Send to ED
Comparison: abrasion, laceration, avulsion, incision, puncture, amputation
pic
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Important aspects of wound to document
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- Document precisely and take photo if possible
- Note:
- Type of wounds
- Size (measure)
- Depth
- Foreign bodies
- Devitalized tissue
- Signs of Infection/Cellulitis:
- Rubor, dolor, calor, tumor
- Purulent discharge
- Increasing area of redness
- Can draw circle around red area w/ permanent marker
Common bacteria in dog and cat bites
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Dog & cat bites are typically polymicrobial infections
Polymicrobes: aerobic and anaerobic bacteria mainly come from animal oral flora, but also from children’s skin and the environment
Pasteurella multocida and Capnocytophaga canimorsus
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- •Pasteurella multocida: Can cause a rapid infx. More common in cats than dogs. Wounds that become infected < 24 hrs are often caused by P. multocida
- •Capnocytophaga canimorsus has been found in the mouths of 24% of dogs and 17% of cats.
Who is at highest risk for dog bites?
- Boys 5-9 yo
- ~4 mil Americans are bitten/year
Where on the body are children usually bitten by dogs?
- = 3x more likely than adults to get bitten
- Younger children: head & neck
- Adolescents: hand & extremities (upper ext)
Characteristics of dogs who bite
- 75% unneutered male dogs
- 50-75% of dogs are known
- >50% are unprovoked
Common breeds that bite
Pit bull breeds, malamutes, chows, Rottweilers, huskies, German shepherds, wolf hybrids
Types of wounds from dog bites
- Crush Injuries (Most dog bites will have some degree of crush injury)
- Lacerations
- Abrasions
- Puncture
- less common in dog bites than cat bites
Most common complication of dog bites + symptoms
- Most common complication is 2ndry infection
- 10-15% infection rate
- Systemic s/s:
- Fever, chills
- Local s/s:
- Local erythema, warmth, increasing pain, edema, exudate
- Dog bites are considered contaminated and contain mixed organisms, need to cover for anaerbic and aerobic!
- Pasteurella multocida & Staphylococcus aureus are the most common aerobic organisms, present in 20-30% of infected dog bite wounds
Laws regarding reporting bites
- Laws vary state by state
- Know the laws where you practice!!
- In every state, must report suspected cases of rabies
- Rabies: suspected animals should be sent for testing. Local or state health dept. can give info on submitting specimens
- Examples of state laws:
- •In MA: Healthcare providers must report any bite by a domestic animal to the Animal Inspector in < 24 hrs
- •In CT: Victim of a dog bite must report the attack.
- Ellis & Ellis, 2014, American Family Physician
Psychological After-Effects of a Dog Bite
- High prevalence of PTSD (25% of pedi pts after DB)
- Common behaviors in children:
- More fearful of dogs
- Avoid dogs/things/places that remind child of the bite
- Increased anxiety
- Sleep disturbance
- Tantrums, aggression
- Decreased school performance
- These behaviors may not appear until months after the bite
- APRNs can help: Educate parents on the symptoms to look out for. Evaluate at f/u. Make referrals to mental health services as needed
Epidemiology / prevalence of cat bites?
- ~400,000/year in US
- Most common in middle age women
- 89% of cat bites are provoked
Common locations of cat bites
Majority (2/3) involve upper extremities and scratches may be on face
Types of cat wounds
- Puncture wounds, abrasions, lacerations
- Caused by cats’ long, sharp teeth & claws
Common pathogens in cat bites
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75% contain Pasteurella multocida
Can cause rapid infection in humans
Wounds that become infected < 24 hours of the bite are often caused by Pasteurella
Complications of cat bites
- 2x risk of infection than dog bites (30-50%)
- More likely to become infected than dog bites
- Progress rapidly (12-24 hours after the bite)
- Deep puncture wounds can lead to osteomyelitis, tenosynovitis, septic arthritis
- Cat scratch fever
- *Bacteria can be inoculated deep into tissue or closed spaces such as joint capsules, which can lead to septic arthritis and osteomyelitis (contiguous or penetrating pathogenesis)
Treatment of cat bites
- Most cat bites are prophylaxed with antibiotics!
- Beta-lactams most effective
- Rabies prophylaxis is the same as for dog bites
Prevalence of human bites
- 3rd leading cause bite wounds treated in the ED
- Often result of 1 person striking another in the mouth w/ a clenched fist
Cause of human bites
- Aggressive behavior
- often in setting of ETOH use (cause of most clenched-fist injuries)
- Accidents during sporting events
- Aggressive play of children in daycare
- Rough sexual play or sexual assault
- Child abuse
- Self-inflicted wounds
Common pathogens in human bites
- Similar to cat/dog, no Pasteurellae or C. canimorsus
- Anaerobes Eikenella corroden
- Viridans streptococci
- Streptococcus pyogenes, S. aureus
- Hepatitis B & C; HIV; HSV
- Similar in that they are polymicrobial infections with aerobic & anaerobic microbes
- Potential for transmitting blood borne pathogens
Most common location for human bites
- >50% occur in upper extremities
- “Love nips” to the face, breasts or genital region
- Most victims of human bites have >1 bite, so thoroughly inspect the patient’s skin