• Foreign bodies [ Accidental tattoo, Puncture wounds, lacerations ]
• Mammalian bites
• Rabies

Foreign bodies

1. Accidental tattoo: Asphalt, dirt, grease and other debris may be ground into an abrasion. A local anaesthetic such as 2% topical lidocaine or local injection of lidocaine will facilitate scrubbing. Imbedded particles should be picked out. Polysporin or Vaseline will gradually dissolve asphalt.
   
   
2. Puncture wounds, lacerations: Foreign bodies are all too easy to miss. A detailed history should heighten clinical suspicion. A ‘foreign body sensation’ experienced by the patient should be taken seriously. Localised sharp pain when palpating over a puncture is a useful sign of the possible existence of a foreign body.

The bottom line is that, although imaging is useful, it is better to also look in the wound.
Generally, if the foreign body is readily visible through the existing wound, it should be removed in the Emergency Department. If removal appears difficult, or surgical exploration is contemplated for co-existent tendon or nerve injury, then a plastic surgeon should be consulted prior to removal. Consultation should be considered for exploratory surgery to remove those deep foreign bodies not readily visible in the wound and are not readily located.

High-pressure injection injuries are particularly dangerous. Paints, oil or grease injected into the hand can spread along the fascial planes as high as the elbow. The entry wound may appear innocuous. Extensive cleaning and debridement is required. Amputation is common.

Certain non-visible foreign bodies may be managed expectantly. Small foreign bodies of relatively non-reactive materials, such as metal, may be left in place and simply followed. Pain, functional impairment, or infection would warrant their removal. There is potential for migration of a foreign body in some body sites thus causing functional impairment (this is especially true of the hand). As a general rule, foreign bodies in a weight bearing location require removal.

Foreign bodies with a high propensity for infection, for example wood, must be removed in total.

``Use of antibiotics should be individualized based on the degree of bacterial contamination, the presence of infection-potentiating factors, such as soil, the mechanism of injury, and the presence or absence of host predisposition to infection. In general, decontamination is far more important than antibiotics. Prophylactic antibiotics should be used in most human, dog, and cat bites, intraoral lacerations, open fractures, and exposed joints or tendons.`` From Management of lacerations in the emergency department. O. Capellan and J. Hollander Emergency Medicine Clinics of North America. Volume 21, Number 1, February 2003

Mammalian bites

Dog and cat bites are prone to infection. Staphylococcus, Streptococcus, Pasturella multicida, various gram negatives and anaerobic bacteria have all been cultured from such infected wounds.

The principles of management of bite wounds include proper wound cleansing and debridement. Facial wounds should be closed, but in general, others should be left open. A plastic surgeon should be consulted, especially for wounds that penetrate joint space, tendon sheath, or into deep muscular tissue. Multiple studies have supported the use of prophylactic antibiotics in the management of bite wounds. Use prophylactic antibiotics for full-thickness skin punctures.

Human bites

Human bites are considered amongst the most dangerous. Infection rates are as high as 50%. Usually a mixed flora is cultured. Staph, strep, gram negatives and anaerobes have all been cultured. Additionally, in 10-30% of such infections, an organism called Ekinella corrodans is cultured. Ekinella corrodans is sensitive to penicillin but is resistant to semi-synthetic penicillins.

A common location for the human bite is over the knuckles. This injury is usually sustained when a closed fist strikes the teeth of an opponent. There is frequently penetratation of the tendon sheath and/or the joint space. The hand must be examined with the fingers in a flexed position so that the deeper structures are in the identical position that they were when the injury was sustained. Only in that position can injury to the underlying structures be visualised through the open skin wound. Sometimes a foreign body such as a broken tooth is found in the wound.

Picture

All such injuries should be referred to the plastic surgeons

Antibiotics use:

Another good source of information regarding the treatment of infectious diseases, including mammalian bites, is the John Hopkins Infectious Disease site at http://hopkins-abxguide.org/.

Rabies

Rabies is a particularly dangerous RNA virus. In North America, the rabies reservoir is principally in skunks, racoons, foxes, and bats. The incubation period is 20-90 days, and is shorter if the virus is introduced through a facial wound.

Local wound care with good cleansing is very important.

Both active (vaccine) and passive (immunoglobulin) immunisation is available. Human diploid cell vaccines have few side effects but are expensive.

The following chart can help determine management:

The Canadian Immunization Guide – 6^th Edition – 2002 is available at
http://www.hc-sc.gc.ca/pphb-dgspsp/publicat/cig-gci/ and contains up-to-date information on the rabies vaccines that are necessary.