That Bites!Back to Basics

Review

Jason R. Frank MD MA(Ed) FRCPC

Dept of Emergency Medicine

Bites & the MCC

• According to the MCC, what are the bites that every doctor should know something about?

Important Medical Bites

MCC List:

1. Dog bites

2. Cat bites

3. Human bites

4. Insect stings

5. Snake bites

• Other list:

1. Spider bites

2. Jellyfish stings

3. Scorpion stings

4. Tick bites

5. Bat bites

Case 1

• A 20 woman presents with this bite• Delivering fliers• Neighbourhood dog• Unsure of owner• 12 hours ago

Case 1

1. Diagnostic issues?

2. Management issues?

3. Plan for this case?

4. Epidemiology?

5. Medicolegal?

Dog Bites

• Many MD visits (12,000 bites/day US)• Usually child <5• 10-20 deaths per year US• Dx Issues:

– 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:

– Abx: Clavulin; Clinda + Cipro– Tetanus– Wound management – ?Closure– Pain management– Rabies prophylaxis– Public health reporting– Safety for all

• Medicolegal– Documentation– Testimony

Case 1 – Your Management?

• A 20 woman presents with this bite• Delivering fliers• Neighbourhood dog• Unsure of owner• 12 hours ago

Case 2

• 75 F• Her cat startled watching Senators loss on CBC• Bit her forearm• 3 hours ago• Pain worse • What should she do?

Cat Bites

1. Diagnostic issues?

2. Management issues?

3. Plan for this case?

4. Epidemiology?

5. Medicolegal?

Cat Bites• 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?

• 75 F• Her cat startled watching Senators loss on CBC• Bit her forearm• 3 hours ago• Pain worse • What should she do?

Case 3

• 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

• Diagnostic issues?• Management issues?• Plan for this case?• Epidemiology?• Medicolegal?

Human Bites• Bacterial Infections

– mouth bugs, including anaerobes, Staph, Strep– Eikenella– Rx Clavulin; Pip-tazo– Tetanus

• Viral infections– HIV, Hep B, Hep C; HSV– PEP

• Wound management• “Closed fist injuries” / “Fight bites”• Other sites: ears, etc• Four incisors, oval

Case 3 – What is Your Plan?

• 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”– More common– Necrotic arachnism– DIC, death– Supportive

Case 5

• 50 diabetic man bit by a snake at a petting zoo

Case 5

• 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

• 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:

1. Dog bites

2. Cat bites

3. Human bites

4. Insect stings1. Hymenoptera

2. Mosquitoes

5. Snake bites

• Other list:

1. Spider bites1. Black widow

2. Brown recluse

2. Tick bites1. Lyme disease

That Bites!Back to Basics

Review

Jason R. Frank MD MA(Ed) FRCPC

Dept of Emergency Medicine