Transcript Frank Insect Bites - Dr Avik Nath h 2010

That Bites!
Back to Basics
Review
Jason R. Frank MD MA(Ed) FRCPC
Presented and modified by Avik Nath
Dept of Emergency Medicine
Bites & the MCC
• According to the MCC, what are the bites that every
doctor should know something about?
NEW SLIDE : MCC Objectives
MCC Key Objectives:
• Examine the patient completely to document the
presence/absence of more than one wound
• Search for evidence of infection (e.g., fever, cellulitis,
discharge), or joint penetration.
NEW SLIDE – Animal Bites
Microbiology
• COMMON BACTERIA IN ANIMAL BITES
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Pasteurella species
Staphylococci
Streptococci
Anaerobic bacteria
• Dog bites
– Capnocytophaga canimorsus
– Causes sepsis (esp asplenic)
• Cat bites
– Bartonella henselae (organism responsible for cat scratch
disease)
• Human bites
– Eikenella corrodens
Important Medical Bites
MCC List:
• Other list:
1. Dog bites
2. Cat bites
3. Human bites
4. Insect stings
5. Snake bites
1. Spider bites
2. Jellyfish stings
3. Scorpion stings
4. Tick bites
5. Bat bites
Case 1
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A 20 woman presents with this bite
Delivering fliers
Neighbourhood dog
Unsure of owner
12 hours ago
Case 1
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Diagnostic issues?
Management issues?
Plan for this case?
Epidemiology?
Medicolegal?
Dog Bites
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Many MD visits (12,000 bites/day US)
Usually child <5
10-20 deaths per year US
Dx Issues:
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6 incisors, straight, large deep punctures
Circumstances; dog ownership; safety
Nature of each wound
r/o rabies
Bacteria: anaerobes, Strep, Staph, etc
• 5-6% dog bites get infected
• Rare sepsis: Capnocytophaga canimorus
Dog Bites
• Tx issues:
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Abx: Clavulin; Clinda + Cipro
Tetanus
Wound management
?Closure
Pain management
Rabies prophylaxis
Public health reporting
Safety for all
• Medicolegal
– Documentation
– Testimony
NEW SLIDE - Dog Bites
• Primary Closure:
– Clinically uninfected
– Less than 12 hours old (24 hours on the face)
– NOT located on the hand or foot
• Most cat and human bites leave open
NEW SLIDE - Dog Bites
• Wounds at high risk for the development of infection
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Crush injuries
Puncture wounds (cats worse than dogs)
Bites involving the hands and feet
Wounds more than 12 hours old (24 hours old on face)
Cat or human bites, except those to the face
Bite wounds in compromised hosts (eg,
immunocompromised, absent spleen or splenic dysfunction,
venous stasis, diabetes mellitus [adults])
NEW SLIDE - Rabies
• Rabies:
– animals uniformly begin to sicken and die within 10 days
(usually five to seven days) of spread of rabies virus from the
CNS to the salivary glands
– a healthy domestic dog, cat, or ferret should be confined and
observed for 10 days
– If the animal remains healthy for the full 10 days, then it did
not have rabies virus in its saliva at the time of exposure.
– Post-exposure prophylaxis should be given immediately if an
exposing animal is rabid or suspected to be rabid
• Passive immunization – rabies immune globulin
• Active immunization – rabies vaccination
– Contact public health
– Unprovoked attacks are more likely by rabid than non-rabid
animals
NEW SLIDE - Rabies
• Rabies:
– If the animal is available for observation, immediate
prophylaxis is indicated when the animal develops clinical
signs of illness.
– In addition, prophylaxis should be started if the person's
significant exposure is to the head or neck, since incubation
periods as short as four days have been reported in bites
this close to the central nervous system
– If the animal remains well for 10 days, the regimen can be
discontinued at that time.
Case 1 – Your Management?
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A 20 woman presents with this bite
Delivering fliers
Neighbourhood dog
Unsure of owner
12 hours ago
Case 2
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75 F
Her cat startled watching Senators win on CBC
Bit her forearm
3 hours ago
Pain worse
What should she do?
Cat Bites
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4.
5.
Diagnostic issues?
Management issues?
Plan for this case?
Epidemiology?
Medicolegal?
Cat Bites
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Similar to dog bites
60-80% infection rate
Bacteria: esp Pasturella multocida
Very rapid cellulitis
Cat-scratch LN: Bartonella
• Rx Clavulin or Doxycyline
• Splint
• Re-check
Case 2 – Your Plan?
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75 F
Her cat startled watching Senators loss on CBC
Bit her forearm
3 hours ago
Pain worse
What should she do?
Case 3
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19 male, HBD
“Minding his own business” at a bar
Assaulted
He “won”
Punched in face
Punched the other guy – cut his knuckle on tooth
Feeling hung over
Wants to leave
Case 3
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Diagnostic issues?
Management issues?
Plan for this case?
Epidemiology?
Medicolegal?
Human Bites
• Bacterial Infections
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mouth bugs, including anaerobes, Staph, Strep
Eikenella
Rx Clavulin; Pip-tazo
Tetanus
• Viral infections
– HIV, Hep B, Hep C; HSV
– PEP
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Wound management
“Closed fist injuries” / “Fight bites”
Other sites: ears, etc
Four incisors, oval
Case 3 – What is Your Plan?
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19 male, HBD
“Minding his own business” at a bar
Assaulted
He “won”
Punched in face
Punched the other guy – cut his knuckle on tooth
Feeling hung over
Wants to leave
Case 4
• Bad field trip to woods
• Multiple kids with “bug bites”
Case 4 continued
• Hymenoptera (honeybees, bumblebees, wasps, ants)
– Anaphylaxis (IgE, non)
– Remove stinger
– 2’ infections (Staph, Strep)
• Tick bites
– Ixodes  Lyme disease (Borrelia burgdorferi)
– RMSF, Ehrichiosis, babesiosis, tularemia, etc
– Rx Doxycycline
• Mosquito bites
– Symptomatic (NSAIDS, antihistamines)
– West Nile Virus
Case 4 continued - Spiders
• Black widow spider
– Aggressive females
– Rare systemic
– Rx antivenom if severe
• Brown Recluse / “Fiddleback”
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More common
Necrotic arachnism
DIC, death
Supportive
Case 5
• 50 diabetic man bit by a snake at a petting zoo
Case 5
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Diagnostic issues?
Management issues?
Plan for this case?
Epidemiology?
Medicolegal?
Case 5 – Snake Bites
• Wound care
• Identify snake
• In Canada: Massasauga rattler
• Antivenom (Rx CroFab)
That Bites! - Summary
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Clear history of events, timing
Identify all wounds
Wound care
Punctures
Foreign bodies
Tetanus
Abx
Other PEP: HIV, Hep B, Hep C, Rabies
Public health
Documentation
That Bites! - Summary
MCC List:
• Other list:
1. Dog bites
2. Cat bites
3. Human bites
4. Insect stings
1. Spider bites
1. Hymenoptera
2. Mosquitoes
5. Snake bites
1. Black widow
2. Brown recluse
2. Tick bites
1. Lyme disease
That Bites!
Back to Basics
Review
Jason R. Frank MD MA(Ed) FRCPC
Presented by Avik Nath
Dept of Emergency Medicine