The most common human bite–related infection of the hand is injury to the knuckles of a person who punches another person in the mouth (called a clenched fist injury or fight bite). Animal bites are also common causes of hand infections. Wound contamination by a number of types of bacteria can result from human and animal bites. All bite injuries are potentially dangerous and can cause severe infections or serious complications (such as tendon infections or infectious arthritis).
Infected bites cause pain, swelling, redness, and tenderness.
(See also Overview of Hand Disorders.)
Doctors base the diagnosis of an infected bite wound on an examination. However, if the skin is broken, an x-ray is often done to detect a fracture, tooth, or other foreign objects, which can cause or worsen infection.
To identify the type of bacteria that is causing the infection, doctors swab inside the wound or remove a sample of pus from the wound and try to grow (culture) the bacteria in a laboratory.
The injured area should be thoroughly cleaned. Doctors usually do a surgical procedure to make sure they clean out the whole wound. Afterwards, they usually leave the wound open to drain. If the infection is not severe and the wound is not deep, people are given antibiotics by mouth to prevent spread of the infection. If doctors suspect there is an infection in the joint (infectious arthritis), antibiotics are given by vein (intravenously) to prevent permanent destruction of the joint. Which antibiotic is effective depends on which bacteria are common in the person’s community. If infection is severe, the person is admitted to the hospital and given antibiotics by vein.
People wear a dressing and elevate the hand as much and as often as possible, ideally above the head, to keep the wound clean and minimize swelling. People sometimes wear a splint to keep the hand immobilized in the most functional position to promote healing.