Human bite infections
Human bite infections are potentially serious infections caused by rapid growth of bacteria in broken skin.
Bites--animal and human--are responsible for about 1% of visits to emergencyrooms. Bite injuries are more common during the summer months.
In adults, the most common form of human bite is the closed-fist injury, sometimes called the "fight bite." These injuries result from the breaking of theskin over the knuckle joint when a person's fist strikes someone's teeth during a fight.
In children, bite infections result either from accidents during play or fromfighting. Most infected bites in adults result from fighting.
The infection itself can be caused by a number of bacteria that live in the human mouth. These include streptococci and staphylococci. Infections that begin less than 24 hours after the injury are usually produced by a mixture of organisms and can cause an infection that will cause the death of a specific area of tissue, in which tissue is rapidly destroyed. If a bite is infected, the skin will be sore, red, swollen, and warm to the touch.
In most cases the diagnosis is made by an emergency room doctor on the basisof the patient's history. Because the human mouth contains a variety of bacteria, the doctor will order a laboratory culture in order to choose the most effective antibiotic.
Treatment involves surgical attention as well as medications. Because bites cause puncturing and tearing of skin rather than clean-edged cuts, they must be carefully cleansed. The doctor will wash the wound with water under high pressure and remove the dead tissue and foreign objects from the wound to prevent infection. If the bite is a closed-fist injury, the doctor will look for torn tendons or damage to the spaces between the joints. Examination includesx rays to check for bone fractures or foreign objects in the wound.
Doctors do not usually suture a bite wound because the connective tissues andother structures in the hand form many small closed spaces that make it easyfor infection to spread. Emergency room doctors often consult surgical specialists if a patient has a deep closed-fist injury or one that appears alreadyinfected.
The doctor will make sure that the patient is immunized against tetanus, which is routine procedure for any open wound. Because of risk of infection, all patients with human bite should be given antibiotics. Patients with closed-fist injuries may need inpatient treatment in addition toan intravenous antibiotic.
The prognosis depends on the location of the bite and whether it was caused by a child or an adult. Bites caused by children rarely become infected because they are usually shallow. Between 15-30% of bites caused by adults become infected, with a higher rate for closed-fist injuries.