Human Bites

Overview

What are human bites?

Human bites are exactly what they sound like, though they are a little more dangerous than you might think. Compared with other mammals (like dogs, bears and big cats), humans don’t have the strongest bite, at 162 lbs per square inch. However, if the skin is broken, tendons and joints may be damaged. Although it’s uncommon, this scenario is most likely to occur in children who are play-fighting.

Around 250,000 human bites are reported each year, among both adults and children – 10% of children who are bitten develop an infection, resulting from bacteria found in human saliva, specifically aerobic and anaerobic bacteria. Bites to the face also account for a small number of overall cases, however they’re very common among children under 10 years old. While children are most likely to suffer one of these injuries, they typically transmit less bacteria, leading to fewer infections in these instances. Men are generally more affected by human bites than women.

Are there different types of human bites?

You might be surprised to learn that, yes, there’s more than one type of human bite. There are two different, distinct types:

  • Occlusion bites: These are what you generally think of when you picture a human bite, and are the most common type. They occur when someone else’s teeth sink into your skin with enough force to break through the surface of the skin.
  • Clenched or closed fist bites: These can be accidental, as they occur when someone’s fist makes contact with another person’s teeth, puncturing the hand in the process. While this type of bite may not be as intentional, it typically creates more serious injuries because the knuckles get damaged. This can lead to infections in the finger’s joints, tendons and/or bones, along with tendinitis and joint stiffness.

Symptoms and Causes

What are the symptoms of a human bite?

It’s likely that you will experience pain and tenderness wherever the injury occurred. The site of the injury may also bleed and swell up. There are certain signs that can tell you if your wound has been infected, including:

  • Intense pain and swelling.
  • Pus around the wound.
  • If the wound feels warm to touch (if it’s hot, the wound is likely infected).
  • Reddening of the skin (erythema) in the wounded area.
  • A fever, chills or generally feeling unwell.

If you’ve been bitten on your finger and lose feeling in your fingertips or have trouble bending or fully straightening your finger, it’s likely a sign that you’ve damaged some tendons and/or nerves.

Management and Treatment

What should you do if you've been bitten - or if someone you're with is bitten?

First, clean out the wound. This should be done with saline solution (salt water) and/or povidone iodine (an antiseptic solution) – but only if it’s been diluted to a 1% concentration. If you have access to a syringe, you should use it to wash the wound, as the pressure will help reduce the level of bacteria. You need to be very careful at this stage not to further damage the wound or the surrounding tissue. If needed, remove any loose, dead skin or foreign objects from the wound (unless you’re worried that you’ll injure yourself further).

When should you see a doctor for a human bite?

If you get bitten, especially on the hands or in a sensitive area, you should go to the doctor for an evaluation because of the high risk of infection and possible complications. Here’s what you can expect:

  • Exam: The doctor will ask you about your medical history, including your history of immunizations, allergies and, if any, your medications. Then they’ll ask you about the bite itself, including how and when it happened and who bit you (and any info you may have about this person), along with other important details that will help them determine how to treat your wound.
  • Cleaning: The doctor will clean out and disinfect the wound again, before assessing it for any potential nerve, ligament, tendon and/or bone damage.
  • Testing: The doctor may take tissue cultures from the site of the wound to analyze for infectious organisms. If they find symptoms of joint or tendon damage, or if the wound appears to be infected, the doctor may order a blood test or imaging tests, such as X-rays.
  • Treatment plan: The doctor will determine which, if any, medications are best for your particular situation. They may close up the wound with non-absorbable stitches. In more severe cases, they may remove all dead tissue (debridement), followed by a skin graft to close the wound. Sometimes surgery is needed if there’s a fracture, joint/tendon damage or a severe infection.

If you or your child isn’t up to date with your vaccinations, a tetanus shot might be necessary. And any bites that puncture the skin deeper than one centimeter also require an immediate tetanus shot.

You’ll need to follow up with your doctor in 24 to 72 hours, and even quicker if you begin noticing any signs of infection.

What medications are used to treat human bites

Your doctor might prescribe medication for you, if needed. Antibiotics might be recommended for soft-tissue infections (7 to 10 days), severe infections (10 to 14 days) and severe bone/joint infections (4 to 6 weeks).

Amoxicillin (Augmentin®) is one type of antibiotic that can be used, though not for those who are allergic to penicillin. If you’re allergic to penicillin, you will likely be prescribed clindamycin, trimethoprim/sulfamethotrexate or ciprofloxacin (Cipro®). Trimethoprim/sulfamethotrexate is most commonly used with children.

Who is at a higher risk of infection following a human bite?

Your overall health and where you were bitten are factors. You’re more likely to get an infection following a bite if you:

  • Have been bitten on the hand, foot, face and scalp, or on a sensitive bone/joint.
  • If you are taking medications that suppress or alter your immune system.
  • Have diabetes.
  • Suffer from alcoholism.
  • Have vascular disease.
  • Are over the age of 50.

Are there complications from human bites?

The risk of infection depends on the type of wound and its location, the general medical condition of the patient and the time that elapses between when the injury occurred and when it is treated.

There can be complications if you don’t get to the ER quickly enough because the infection can spread over time. Bite wounds on the hands, upper limbs, nose and ear cartilage tend to pose more complications than those on other parts of the body. Even a seemingly minor injury can damage the underlying joints, tendons or bones, or lead to a serious infection. There are a few different signs that your human bite wound may be turning into something worse, including:

  • An inability to use any part of your body.
  • Redness on your body that is actively spreading.
  • Drainage from the wound.
  • A fever or chills.
  • Generally feeling unwell.

These infections might cause permanent damage to the affected part of the body unless they’re treated quickly. For example, a closed fist bite can cause damage to the metacarpophalangeal (MCP) joint, sometimes leading to arthritis. In a worst-case scenario, amputation is possible. With occlusion bites, you may be at risk of developing osteomyelitis, septic arthritis, tenosynovitis and/or tendinitis.

There has been anecdotal evidence of human bites transmitting HIV and tetanus, though both are extremely rare and unlikely.

Can a human bite kill you?

Human bite wounds can be very dangerous, largely due to the many types of bacteria transmitted through human saliva. Complications from a human bite can be very serious, including severe infection and permanently damaged bones, joints and/or tendons. It’s unlikely that a human bite will be fatal, especially if you seek out proper medical care, particularly around the infection.

Outlook / Prognosis

Outlook

The recovery time from a human bite varies greatly depending on a couple different factors:

  • The type, location and severity of the bite.
  • The resulting damage and potential infections.
  • Any underlying medication conditions.

Even after you’re initially treated, you should closely monitor the wound area to watch for signs of infection. Severe bites may have lasting effects, ranging from long-lasting effects to scarring. Remember, it’s important to see your doctor if you’re dealing with a human bite, to minimize any complications.

Last reviewed by a Cleveland Clinic medical professional on 07/02/2020.

References

  • Patil, Pradnya D, Panchabhai, Tanmay S, Galwankar, Sagar C. . Journal of Emergencies, Trauma and Shock. 2009; 2(3): 186-190. Accessed 5/5/2020.Managing human bites (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2776367/)
  • American Academy of Orthopedic Surgeons. Accessed 5/5/2020.Human Bites (http://www.orthoinfo.aaos.org/topic.cfm?topic=A00003)
  • Bula-Rudas, Fernando J, Olcott, Jessica L. . Pediatrics in Review. 2018; 39(10). Accessed 5/5/2020.Human and Animal Bites (https://pedsinreview-aappublications-org.ccmain.ohionet.org/content/pedsinreview/39/10/490.full.pdf)

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