|Classification and external resources|
Military working dog training to attack by biting
A bite is a wound received from the teeth of an animal, including humans. Animals may bite in self-defence, in an attempt to prey one food, and as part of normal interactions. Other bite attacks may be apparently unprovoked. Self-inflicted bites occur in some genetic illnesses, such as Lesch-Nyhan syndrome. Biting is an act that occurs when an animal uses its teeth to pierce another object, including food, flesh, and inanimate matter. A person bitten by an animal potentially carrying parvovirus or rabies virus should consult a medical doctor immediately. An animal bite victim may also incur serious bacterial infections of the bone called osteomyelitis which can become life-threatening if untreated, whether or not the animal has parvovirus or rabies virus.
Bites are usually classified by the type of creature causing the wound. Many different creatures are known to bite humans.
- Spider bite
- Insect bites and stings
Vertebrates other than humans
- Bites from dogs are commonplace, with children the most common victims and the face the most common target. About 4.7 million dog bites are reported annually in the United States.
- Other companion animals, including cats, ferrets, and parrots, may bite humans.
- Wildlife may sometimes bite humans. The bites of various mammals such as bats, rabbits, wolves, raccoons, etc. may transmit rabies, which is almost always fatal if left untreated.
Involuntary biting injuries due to closed-fist injuries from fists striking teeth (referred to as reverse bite injuries) are a common consequence of fist fights. These have been termed "fight bites". Injuries in which the knuckle joints or tendons of the hand are bitten into tend to be the most serious.
In spite of their name, love bites are not biting injuries (they involve bruising from sucking, and the skin is not broken), although actual biting injuries are sometimes seen as the result of fetishistic activities.
Signs and symptoms
Bite wounds raise a number of medical concerns:
- Generalized tissue damage due to tearing and scratching
- Serious hemorrhage if major blood vessels are pierced
- Infection by bacteria or other pathogens, including rabies
- Introduction of venom into the wound by venomous animals such as some snakes
- Introduction of other irritants into the wound, causing inflammation and itching
Bite wounds should be cleaned and debrided as necessary, but not closed. Ampicillin/sulbactam is indicated as HACEK endocarditis, specifically Eikenella, is the most worrying complication. A punctate wound over a joint surface should be regarded as an open joint injury until proven otherwise.
Bite wounds are washed, ideally with povidone-iodine soap and water. The injury is then loosely bandaged, but is not sutured due to risk of infection.
Antibiotic prophylaxis is recommended for dog and cat bites of the hand, and human bites if they are more than superficial. Evidence for the need for antibiotic prophylaxis for bites in other areas is inconclusive.
For empirical therapy, the first choice is amoxicillin with clavulanic acid, and if the person is penicillin-allergic, doxycycline and metronidazole. The antistaphylococcal penicillins (e.g., cloxacillin, nafcillin, flucloxacillin) and the macrolides (e.g., erythromycin, clarithromycin) are not used for empirical therapy, because they do not cover Pasteurella species.
Animal bites inflicted by some animals, including carnivorans and bats, can transmit rabies. The animal is caught alive or dead with its head preserved, so the head can later be analyzed to detect the disease. Signs of rabies include foaming at the mouth, self-mutilation, growling, jerky behavior, and red eyes.
If the animal cannot be captured, prophylactic rabies treatment is recommended in most places. Certain places, such as Hawaii, Australia, and the United Kingdom, are known not to have native rabies. Treatment is generally available in North America and the Northern European states.
Tetanus toxoid is indicated for virtually any bite that punctures the epidermis, and tetanus immune globulin is indicated in patients with more than 10 years since prior vaccination. Tetanus boosters (Td) should be given every ten years.
|Prior toxoid||Clean minor wounds||All other wounds|
|< 3 doses||TT: yes, TIG: no||TT: yes, TIG: yes|
|≥ 3 doses||TT: if last dose ≥ 10yr
|TT: if last dose ≥ 5yr, TIG: no|
TT = tetanus toxoid; TIG: tetanus immune globulin
- Kenneth M. Phillips (2009-12-27). "Dog Bite Statistics". Retrieved 2010-08-06.
- Questions and Answers about Dog Bites
- "BestBets: Antibiotics in cat bites".
- Oehler RL, Velez AP, Mizrachi M, Lamarche J, Gompf S (2009). "Bite-related and septic syndrome caused by cats and dogs". Lancet Infect Dis 9 (7): 439–47. doi:10.1016/S1473-3099(09)70110-0. PMID 19555903.
- Medeiros I, Saconato H (2001). "Antibiotic prophylaxis for mammalian bites". In Medeiros, Iara Marques. Cochrane Database Syst Rev (2): CD001738. doi:10.1002/14651858.CD001738. PMID 11406003.
- "BestBets: Oral antihistamines for insect bites".