Because human teeth are not particularly sharp, most human bites cause a bruise and only a shallow tear (laceration), if any. Exceptions are on fleshy appendages, such as the ears, nose, and penis, which may be severed.
The clenched-fist injury, or fight bite, which occurs on the knuckles of a person who punches another person in the mouth, is likely to become infected. A clenched-fist cut frequently involves the finger tendon that passes over the knuckle.
Sometimes the biting person transmits diseases, such as hepatitis. Transmission of the human immunodeficiency virus (HIV) is extremely unlikely because the concentration of the virus in saliva is lower than that in blood and because substances in saliva inhibit the virus’s activity.
(See also Introduction to Bites and Stings.)
Human bites are painful and usually produce a mark on the skin with the pattern of the teeth. Fight bites typically leave only a small, straight cut over a knuckle. A lacerated finger tendon often results in difficulty moving the finger in one direction. Infected bites become very painful, red, and swollen.
Human bites are cleaned by flooding the wound with sterile salt water (saline) and cleansing it with soap and water.
Severed parts can sometimes be reattached. Severed parts should be wrapped in a damp paper towel or washcloth and sealed in a plastic bag. That closed bag should be placed in a second bag with ice. Severed parts should never be placed directly on ice or submerged in water.
Tears, except those involving the hand and those that have occurred many hours ago, are usually surgically closed.
Most people with human bites that have broken the skin are given antibiotics by mouth to prevent infection. Infected bites are treated with antibiotics and often must be opened surgically to root out foreign objects (for example, a broken tooth) and clean the wound. Sometimes an imaging study such as an x-ray or ultrasonography is also done to locate hidden foreign objects.
If a fight bite becomes infected, hospitalization may be needed for administration of intravenous antibiotics.
If the biting person is known or suspected to have a disease that may be spread by biting, preventive treatment may be necessary.