Mammalian bites
Background
- 5% of untreated dog bites will become infected (similar to rate of non-bite wounds)
- 80% of untreated cat bites will become infected
- Human Bite - (Also see Closed fist infection)
High-Risk Wounds
- Cat, human, livestock, or monkey bites
- Deep puncture wounds
- Hand or foot wounds
- Bites in immunosuppressed patients
Clinical Presentation
- Depends on source of bite - bite marks or puncture wounds.
Differential Diagnosis
Envenomations, bites and stings
- Hymenoptera stings (bees, wasps, ants)
- Mammalian bites
- Closed fist infection (Fight bite)
- Dog bite
- Marine toxins and envenomations
- Toxins (ciguatera, neurotoxic shellfish poisoning, paralytic shellfish poisoning, scombroid, tetrodotoxin
- Stingers (stingray injury)
- Venomous fish (catfish, zebrafish, scorpion fish, stonefish, cone shells, lionfish, sea urchins)
- Nematocysts (coral reef, fire coral, box jellyfish, sea wasp, portuguese man-of-war, sea anemones)
- Phylum porifera (sponges)
- Bites (alligator/crocodile, octopus, shark)
- Scorpion envenomation
- Reptile envenomation
- Spider bites
Diagnostic Evaluation
- Clinical diagnosis, based on history and physical exam
- Consider X-ray if concern for retained foreign body (e.g. tooth)
Management
Indications for Primary Closure of Mammalian Bites
- Consider closure if all of the following are true:
- Not a face or scalp wound
- Repair can occur within 6hr of injury (time dependent upon individual judgment)
- Repair only requires single-layer closure; no devitalized tissue
- No underlying fracture
- No systemic immunocompromising conditions
Antibiotics
Cat and Dog Bites
Coverage for Pasteurella, Strep, and Staph
- Consider for high-risk wounds
- wounds reaching the level of the muscle/tendon, wounds to the hand[1], violation of bone or joint capsule, immunocompromised hosts, wounds associated with significant local edema
- Amoxicilin-clavulanate 875mg PO BID x 5-7 days OR[2]
- Doxycycline 100mg PO BID x 14 days if penicillin allergic [3]
- Clindamycin 450mg (5mg/kg) PO q8hrs daily x7 days PLUS
- Ciprofloxacin 500mg PO q12hrs x 7 days OR
- TMP/SMX 2DS tabs (5mg/kg) PO q12hrs
Human Bites
All human bites should be strongly considered for antibiotic therapy.[4]
Requires polymicrobial coverage for: S. aureus, Strep Viridans, Bacteroides, Coagulase-neg Staph, Eikenella, Fusobacterium, Cornebacterium, peptostreptococus
- Amoxicilin-clavulanate 875mg PO BID x 5-7days OR
- Clindamycin 450mg (5mg/kg) PO q8hrs daily x7 days PLUS
- Ciprofloxacin 500mg PO q12hrs x 7 days OR
- TMP/SMX 2DS tabs (5mg/kg) PO q12hrs
Mammalian Bites Severe Infections
- Ampicillin/Sulbactam 3g IV (50mg/kg IV) q 6hrs daily OR
- Cefoxitin 1g IV q8hrs (25mg/kg q6hrs) OR
- Pipericillin/Tazobactam 4.5g IV (80mg/kg IV) q8hrs OR
- Ceftriaxone 1g (50mg/kg IV) once + Metronidazole 500mg IV q8hrs OR
- Clindamycin 600mg IV q8hrs PLUS
- TMP/SMX 5mg/kg IV q12hrs OR
- Ciprofloxacin 400mg IV q12hrs OR
Rabies prophylaxis
- Rabies immune globulin should be inidividualized[5]
- Indicated for bites from bats, monkeys, skunks, raccoons, foxes. In the U.S. rare for dog and cat bites
See Also
References
- ↑ EBQ:Antibiotic prophylaxis for mammalian bites
- ↑ Griego RD, Rosen T, Orengo IF, Wolf JE. Dog, cat, and human bites: a review. J Am Acad Dermatol. 1995;33:1019–29.
- ↑ Talan DA, Citron DM, Abrahamian FM, Moran GJ, Goldstein EJ. Bacteriologic analysis of infected dog and cat bites. Emergency Medicine Animal Bite Infection Study Group. N Engl J Med. 1999;340:85–92.
- ↑ EBQ:Antibiotic prophylaxis for mammalian bites
- ↑ Human rabies—Washington, D.C., 1995. MMWR Morb Mortal Wkly Rep. 1995;44:625–7.