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Symptoms and Signs of Human Bites

Doctor's Notes on Human Bites

Human bites, in many instances, show signs and symptoms of skin penetration in the shape of persons teeth that is lacerated, bleeding and/or bruised. However, if the person with the suspected human bites was drunk or was fighting, that person may have hit someone in the teeth resulting in lacerations on his or her hand and/or fist (knuckles) that are essentially human bites. Consequently, signs and symptoms of human bites also include any skin breaks possibly caused by human teeth. Other signs and symptoms may include increasing pain and tenderness at the bite site, redness and/or increase swelling at the site. Later developments (hours to days) may include pus drainage, red streaks and swollen glands associated with the bite site. Some bites result in visible tissue loss and/or bone, cartilage or tendon damage (for example, finger, nose, ear or scalp bites); these human bites are difficult to treat. Any bite marks in the genital area of children may be a sign of abuse.

Human bites causes are usually accidental or intentional; for example, they happen inadvertently during sports activities or accidentally during other activities - intentionally when a child bites another child or when adults fight, especially with their fists. However, some patients may not know they may have had a human bite.

Medical Author:
Medically Reviewed on 3/11/2019

Human Bites Symptoms

A human bite is generally obvious, but on occasion the victim is unaware (for example, the bite occurred while the victim was drunk) or reluctant to tell others (for example, a hand injury due to a fight). Use caution in ignoring cuts over the knuckles if there is the chance the cut happened in a fight, especially if the cuts came from hitting another person in the mouth. Otherwise, the two most important things to know about a bite are whether there is a skin break or signs of infection.

Signs of a skin break

  • A skin break increases the risk of infection, and it also makes it necessary to give a tetanus booster if the affected person's tetanus status is not up to date. A skin break is often obvious but can be difficult to tell in some cases. Any skin area that looks like the top layer of skin has come off should be considered a skin break. When in doubt, seek a health care professional's opinion. A raw appearance to the area or the oozing of clear fluid is a sign of a skin break.

Signs of infection (note that infection can occur even in properly treated bites)

  • Increasing pain and tenderness: Although all bites hurt initially, the pain usually gets steadily better. If a bite begins to hurt more after time passes, this can be the first sign of infection. Increased pain from an infection is usually matched by increased tenderness when the area of the bite is touched. Typically, this begins 1-2 days after the bite but can occur even later with deeper infections.
  • Increased or new redness: Some color changes can be expected at the beginning, particularly bruising and some redness, but this usually does not get much worse after the first few hours. An increase in redness is a warning sign of infection.
  • Increased swelling: Some swelling is expected initially, but this usually peaks on the first day. If the bite swells up more after the first day, it may be a sign of infection.
  • Fever: A new fever in someone with a bite should be cause for concern. However, waiting for a fever to be sure there is an infection is also wrong. Most people with human bite infections do not get a fever until the infection has spread significantly. If the area around the bite itself feels very warm, even if there is no actual rise in the whole body temperature, this could also be a sign if an infected wound bite.
  • Pus drainage: Pus is yellow and will generally be a late sign of infection. This drainage needs to be distinguished from clear oozing that can occur during the first few hours if the skin is scraped by teeth. This clear oozing is not a sign of infection. If in doubt, the affected person should consult a healthcare practitioner.
  • Red streaks: When you can see thin red streaks running toward the center of the body from a wound, infection is usually present. This condition is sometimes called blood poisoning (the medical term for this condition is lymphangitis), even though this has nothing to do with the bloodstream. What is occurring is an inflammation of the lymph vessels, part of the body's defense system against infection that includes the lymph glands or nodes. Signs and symptoms of lymphangitis should trigger an immediate visit to your health care professional or emergency department.
  • Swollen glands: These may occur in areas near the bite as the lymph glands react to protect the body. For example, if a hand is infected, sore, swollen glands on the inside of the elbow or armpit of the same arm as the bite may develop.

Human Bites Causes

Human bites can be either accidental or intentional.

  • Intentional bite injury: This generally happens during fights and can result in a wide range of injuries from minor bruising to partial loss of body parts (for example, ears or nose). Unfortunately, this can also be an injury seen in child abuse, sexual abuse, and self-mutilation.
  • Closed fist injuries: This bite occurs when someone punches another person in the mouth or, occasionally, accidentally strikes another in the mouth during sports or horseplay. These bites can cause damaging hand injuries and can be very serious if not properly treated. It is important to share this information with your healthcare professional as a cut secondary to contact with a person's mouth is treated significantly different from a cut due to a sharp surface or knife.
  • Accidental bites: Typical head or other body part bites occur when clashing with another person's tooth. These can be minor or, in the case of a head wound in young children, very serious.
  • "I didn't know it was a bite!" category: Yes, we frequently run the risk of problems from doing things to ourselves that technically qualify as bites. For example, it is not a good idea to bite your nails because this can lead to an infection known as paronychia or a hangnail. Similarly, it is almost a reflex to suck on wounds or to kiss a child's boo-boo, but if you introduce mouth bacteria, it could lead to problems such as an infection.
  • Love bites (for example, hickeys): These qualify as a human bite. However, if bruising is the only sign with no skin break, these are largely harmless. Other "love bites" cross the line into intentionally inflicted wounds and may be more serious. Any bite marks in the genital area in children need to be evaluated as a possible sign of abuse.

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Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.