What Is A Bite Wound

Introduction

A bite wound is an injury inflicted by the teeth of an insect, an animal or a human. There are many different forms of bite wounds and each of them needs managed differently. Treatment of the bite depends on the animal which caused the bite, the type and severity of the wound and any complicating factors such as the patient's age, additional trauma and significant past medical history.

Common causes of bite wounds 

Although any species of animal with teeth can inflict a bite wound, the most common animal bite wounds are those from dogs, cats or humans. As not all people affected by a bite wound seek medical attention,it is difficult to say how common the bite wounds are. Around 50% of the population will suffer from a bite wound during their lives, and in 9 out of 10 of cases, the bite comes from a domesticated animal.¹ 

Dog bites

Bites from dogs are the most common type of bite needing medical treatment. The dog inflicting the bite will most often be a pet provoked by an individual playing with it. Dog bites are more likely to affect children, mainly under the age of 5. Those children suffer from bites in the area of the face, whilst older children or adults need medical attention around their arms and legs.³

Dogs have long canine teeth and powerful jaws that can cause two types of woundsThe canine teeth (long, sharp teeth located at the level of the eyes) create puncture wounds going into the skin, increasing the risk of infection as the dirt can get stuck in the wound under the skin. On the other hand, the powerful jaws of the dogs put pressure on the skin and can cause shearing or crushing wounds. In most severe cases, the dog’s jaw clenching can damage the underlying bone or tore off body parts (avulsion injury). 

Cat bites

After dogs, cats are the second most common animal to inflict bite wounds. As with dogs, the cat will often be a pet provoked by the individual to bite. Unlike dog bites, cat bites are more likely to occur in adults than in children. Women are more likely to be affected by the cat bite than men. Cat bites are usually inflicted on the arms and differ from dog bites. Canine teeth of cats are longer and so result in deeper puncture wounds. However, cats have weaker jaws so they are less likely to cause a crushing injury.^1,4

Human bites

Bite wounds inflicted by humans are less common than those inflicted by dogs or cats. The location of the wound will vary depending on the situation leading to the bite. In cases where the bite occurs during playing or fighting, the bite wound will most often be to the hands or fingers. In cases of sexual assault, bite wounds may be inflicted on the breasts or genitals.¹ As with any bite injury a human bite is at risk of infection and, whilst very rare, human bites carry the additional risk of transmitting blood-borne viral infections such as hepatitis C and HIV.³ 

Wild animal bites

Bites from wild animals are much less common than those from domesticated animals and the species of animal inflicting the bite will vary depending on locations. For example, in urban areas with a rising number of monkeys, monkey bites are becoming increasingly common. Other wild animals which are at risk of inflicting bites include bats, snakes and some species of fish. Bites can also be caused by animals infesting a living space, such as rats and mice.⁴

Insect bites

As with wild animal bites, the species of insect causing bite wounds will vary depending on geographical location. In the UK, bites can be inflicted by ticks, fleas, bed bugs, midges and mosquitoes.⁵ Whilst insect bites are often no more than an inconvenience, causing a temporary localised skin reaction and itching, an insect bite can sometimes lead to an anaphylactic (allergic) reaction requiring immediate emergency treatment. Some insects also transmit infections through their bites. In the UK, tick bites can transmit a bacteria which causes an infection called Lymes disease. Mosquito bites transmit a disease called malaria, in parts of the world where this disease is endemic (transmitting in certain local tropical and subtropical areas).

What damages can a bite wound cause?

A bite can cause damage to the skin, soft tissues, muscles and sometimes even bones. After a bite, these injuries can occur: 

• Abrasion injuries

 happen when the top layer of the skin, called the epidermis, is scraped away to reveal the underlying tissue and blood vessels. 

• Lacerations 

occur when the outer layer of the skin and the underlying soft tissues are torn. Lacerations from bite wounds have ragged edges and surrounding bruising from damage to the blood vessels

• Crush injuries 

occur as a result of the pressure applied to the tissues from a bite causing direct tissue damage and can also result in necrosis (death) of the soft tissues due to disruption of the blood flow

• Puncture wounds 

deep wounds which result from a thin sharp object breaking through the epidermis and pushing through the underlying soft tissues. Puncture wounds from bite injuries are a high risk of infection as bacteria can be pushed deep within the soft tissues.^3,6 

What should I do if I suffer from a bite wound?

Treatment of a bite wound will depend on several factors:

• the animal which caused the bite 
• the location of the bite wound on the body
• the severity of the wound
• the risk of the bite causing infection

First aid for bite wounds should include:

• encouraging the wound to bleed (unless it is bleeding already)
• removal of any debris in the wound such as pieces of dirt, teeth or hair
• washing the wound thoroughly with clean water
• pressing a dry absorbent cloth against the wound if it is bleeding heavily⁷ 

When to seek medical help:

• if the bite is bleeding heavily
• if there is debris in the wound which cannot be easily washed out
• if the bite wound is to the hands, feet or face
• if the bite was by a human
• if the bite occurred whilst in an area where rabies is endemic.

Due to the bacteria that live in the mouths of all animals, bite wounds have a high risk of becoming infected. People who have suffered from a bite wound will often be prescribed prophylactic (disease-preventing) antibiotics which are given to prevent a potential infection. The type of antibiotic given and how long it needs to be taken for will depend on the animal which caused the bite and how severe the bite is. People who have suffered from a bite wound may also require a tetanus vaccination if they have not previously been vaccinated.¹ 

In more severe bite cases, the patient may require either a local or general anaesthetic (medicine stopping you from feeling pain) so that the wound can be fully explored by a surgeon. Dead or infected tissue may need to be surgically removed in a procedure termed debriding. If large amounts of tissue are damaged or need to be removed, the patient may require skin grafts (replacement of damaged skin with a new skin) to close the wound. Skin grafting may also be required to achieve the best cosmetic outcome in cases where the bite wound is to the face.⁸ 

FAQs

How can I avoid an animal bite?

The majority of animal bites are caused by domesticated dogs and occur in children. The risk of a bite occurring can be reduced by teaching children how to behave safely around pets (not to disturb them when they are eating or sleeping and not to play with them without an adult present). Training dogs appropriately and avoiding aggressive play with them can prevent a bite injury. Dogs that are known to have aggressive tendencies should be kept away from children. Children and adults should also avoid approaching strange dogs or cats and provoking them to attack.¹ 

Insect bites can be avoided by using appropriate insect repellant, keeping food and drinks covered to avoid attracting insects.  Covering skin at times when insects are more active, such as sunset, could help with preventing insect bites and potential infections. In areas where mosquitos are particularly active, using coverings like mosquito nets can help.⁵

How will I know if a bite has become infected?

If you have suffered from a bite and it has become infected, then the wound may become more red, hot and swollen. There may be fluid or pus (white, yellow or green liquid) leaking from the wound and you may notice an unpleasant smell. If the infection becomes severe you may develop a fever and signs of sepsis. Please seek medical attention if you develop an infection or a lump that worries you. 

What are the long-term consequences of suffering from a bite wound?

Most animal bite wounds are simple and heal well. However, in more severe wounds there can be extensive damage to the soft tissues which can result in long-term scarring. Bites can damage nerves, resulting in chronic (long-term) loss of sensation, ability to move certain body parts or chronic pain. In wounds that become infected, the infection may spread to other organs such as the bone, heart and brain. Bites from certain animals can transmit infections such as rabies, cat-scratch disease and tetanus.⁹

Suffering from a bite wound can also result in psychological effects. Anxiety and post-traumatic stress disorder can occur after a distressing event. Scarring that can occur from a bite to the face may lead to low self-esteem and depression. 

Summary

Bite wounds are a significant cause of illness and death worldwide. The majority of bite wounds are caused by domesticated dogs and are most prevalent in children. Immediate first aid in the form of wound irrigation (washing with clean water) followed by appropriate medical care results in the best outcome for patients who have suffered from a bite wound. Due to the high risk of infection, a person who has suffered from a bite wound will often require prophylactic antibiotics to prevent infection from developing.