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Source: Fish DN, Pendland
SL, Danziger LH. Skin and Soft-Tissue Infections. In: DiPiro, JT,
Talbert RL, Yee GC, Matzke GR, Wells BG, Posey LM. Pharmacotherapy:
A Pathophysiologic Approach. 8th edition. http://accesspharmacy.com/content.aspx?aid=8002378.
Accessed July 22, 2012.
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- Soft-tissue injury from cat, dog, or human bite.
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- Animal bite
- Dogs: Most infections polymicrobial; most
frequently isolated organisms Pasteurella spp.,
streptococci, staphylococci, Moraxella,
and Neisseria. Most common anaerobes Fusobacterium spp., Bacteroides spp., Porphyromonas, and Prevotella.
- Cats: Infections frequently caused by P. multocida.
- Human bite
- Most often caused by normal oral flora, including
both aerobic (Streptococcus spp., Staphylococcus spp., and Eikenella corrodens) and anaerobic
(Fusobacterium, Prevotella, Porphyromonas, and Peptostreptococcus spp.) microorganisms.
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- Animal bite
- High risk of infection owing
to pressure exerted during bite and large number of potential pathogens.
- Cat bites: higher incidence of septic arthritis and osteomyelitis
- Dog bites: crush injuries with much devitalized tissue
- Human bite
- More serious and prone to infection
than animal bites.
- Hand (most common): Force of punch to mouth causes breach
in capsule of metacarpophalangeal joint, leading to direct inoculation
of bacteria into joint or bone.
- Tendons carry bacteria
into deeper spaces of hand, resulting in more extensive infection.
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- Animal bites
- Dog bites more common than
cat bites
- Most commonly seen in males <20 years
of age
- Locations:
- 70% to extremities
- Facial bites in children <5 years of age
- Infection rates with cat bites more than double those seen
with dog bites
- Human bites
- Most often involve hands, either
self-inflicted or due to traumatic laceration (e.g., “fight
bites”)
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- Animal bite
- 20% of dog bites
and 30–50% of cat bites become infected
- Puncture wound
- Have not sought medical attention within 12 hours of injury
- Age >50 years
- Human bite
- Infections occur in 10–50% of
bites.
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- Animal bite: Patient generally presents either immediately
after bite for general wound care or >12 hours after injury due
to clinical signs of infection.
- Human bite: Most clenched-fist injuries are infected by time
patients seek medical care and require hospitalization.
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- Animal bite:
- Pain
- Swelling
- Purulent discharge
- Localized cellulitis
- Fever uncommon
- Concomitant adenopathy or lymphangitis in <20% of
cases
- Human bite:
- Pain
- Swelling
- Purulent discharge
- Decreased range of motion
- Adenopathy in adjacent lymph nodes
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Means of Confirmation
and Diagnosis
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- Patient report of attack and/or injury
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- Animal bite:
- Culture for aerobic and anaerobic
bacteria; not needed if <8 hours or >24 hours elapsed since bite and
no signs of infection
- Human bite
- Complete blood count (CBC): leukocytosis
present with severe infection
- Culture for aerobic and anaerobic bacteria
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- Human bite: radiographic evaluation if damage to bone
or joint suspected.
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- Animal bite: obtain immunization history ...