7-8
Because human bite wounds may be intentional injuries, always consider the potential for alcohol, child,
and spouse abuse.
Focused History: Who or what bit you? When were you bitten? Where were you when you were bitten?
(aids in assessment and treatment, but the history provided concerning human bites is known to be
notoriously unreliable, unlike animal bites. Animal bites: Determine the kind of animal and its status [i.e.,
general health, rabies vaccination status, behavior]; the time and location of the incident; the circumstances
surrounding the bite [i.e., defensive vs. unprovoked]; and the whereabouts of the animal [loose in the wild
or observable in quarantine]. Animal bites, particularly in developing countries, carry a high risk of rabies
infection [see ID: Rabies]. Human bite wounds: Often infected when patients present for the first time because
the wounds appeared so innocuous and the patients delayed seeking care. Other aspects that influence
presentation include the patient’s health status: HIV status of biter, tetanus immunization status, time delay
since receipt of the injury, amount of disability encountered, and any underlying disease). Have you been
immunized against tetanus? (determines status of tetanus prophylaxis.)
Objective: Signs
Using Basic Tools: Adequate visualization may require superficial surgical extension of the wound to
determine involvement of tendon sheaths. Maintain high index of suspicion for infection.
- Clenched fist injury: Evaluate integrity of extensor tendons; inspect for signs of infection (hot, swollen,
red), palpate for crepitus; inspect for loss of knuckle height, or penetration into the joint capsule. - Bite to a finger: Carefully inspect and palpate all bite wounds of the fingers for deeper penetration
into underlying structures. Evaluate for integrity of the extensor and flexor tendons; inspect for
evidence of flexor tenosynovitis. - Bites about the head: Ear and nose bites: Inspect for loss of tissue; palpate for cartilage tears and
depth of penetration into adjacent structures. - Consider when appropriate: Distal neurovascular status, tendon or tendon sheath involvement, bony
injury (particularly in the skull of infants and children), joint space violation, visceral injuries, and
foreign bodies (e.g., teeth in the wound). - Consider possible cervical spine injuries inflicted from shaking by large animals.
Using Advanced Tools: X-Rays: Clenched fist injuries have an associated risk of metacarpal head fracture
that may require surgical treatment.
“Old” infected bites may reveal cortical erosion, periosteal new bone formation or bone loss seen with
osteomyelitis.
Assessment: Diagnose based on history of a bite, wound appearance and captured specimens (teeth).
Differential Diagnosis - other animal bites, insect bites; cellulitis or deep hand infections due to other
causes; foreign bodies from other trauma
Plan:
Treatment
- Bite site and appearance:
A. Superficial human bites (mixture of abrasions and contusions) can be managed adequately with only
local cleansing and tetanus immunization.
B. Bites to the ear and nose: When associated with tissue loss or violation of cartilage require consulta-
tion with surgery (plastic surgery or ENT if possible). Penetrating bites in cartilage are slow to heal
due to the limited blood supply and difficulty in treating chondritis.
C. Consider primary closure in relatively clean wounds or wounds that can be effectively cleansed.
Facial wounds, because of the excellent blood supply, are at a low risk for infection even with primary
closure.
D. Deep bite wounds, animal bites, those to the lower extremities, those with a delay in presentation, or
those in compromised hosts generally should be left for closure by secondary intention. - Irrigate wounds with water or sterile saline (preferred) using a 19 gauge blunt needle and a 35ml syringe
to provide adequate pressure (7psi) and volume. Flush individual punctures with approximately 200 cc of
irrigation solution. Heavily contaminated wounds may require more. - Debride devitalized tissue, particulate matter and clots to provide clean wound edges that will result in