A wound infection occurs when germs such as bacteria gain access to and grow within the damaged skin of a wound. Symptoms can include increasing pain, swelling, and redness. More severe infections may cause nausea, chills, or fever.

A person may be able to treat minor wound infections at home. However, people with more severe or persistent wound infections should seek medical attention.

This article describes preventing, recognizing, and treating an infected wound. It also covers risk factors, complications, when to see a doctor, and medical treatment.

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An infected wound usually gets worse instead of better. Any pain, redness, and swelling will typically increase in intensity.

Redness around the wound is wider than a person’s thumb, which may also indicate an infection.

Wound infections can also lead to other symptoms, such as:

  • warm skin around the wound
  • yellow or green discharge coming from the wound
  • the wound giving off an unpleasant odor
  • red streaks on the skin around the wound
  • fever and chills
  • aches and pains
  • nausea and vomiting

Wounds become infected when bacteria enter and colonize the cut or wound. Common bacteria that may cause a wound infection include:

People with a small infected wound may be able to treat the wound at home.

Whether or not a person can determine if their cut is infected, they can begin by following these steps:

  1. Ensure that all necessary equipment is clean. For example, if using tweezers, clean them with rubbing alcohol first.
  2. Thoroughly wash the hands with soap and warm water, then rinse and dry them.
  3. If there is active bleeding, hold a clean bandage or gauze to the wound and apply pressure until it stops.
  4. Clean the cut or scrape by running warm water over it for several minutes. Use warm, soapy water to clean the surrounding skin, but avoid getting soap in the wound.
  5. Make sure that there is no dirt or debris, such as grass or gravel, in the wound. To remove debris, either use tweezers or carefully and gently rub the wound with a soft, damp cloth.
  6. If desired, apply a thin layer of antiseptic ointment or petroleum jelly to the cut or scrape.
  7. Allow the skin to air-dry before covering it with gauze or a bandage. There is usually no need to cover minor cuts and scrapes.

These steps will help a person protect the cut or wound from infection.

  1. Wash the wound immediately by running clean water over it for several minutes. Then, clean the skin around the wound with warm, soapy water. If it is not possible to use clean water, treat the wound with alcohol wipes.
  2. Allow the skin to air-dry.
  3. Apply an antiseptic ointment to the wound.
  4. Protect the injury with gauze or another suitable dressing.

Other tips

  • Change the wound dressing at least once a day. Replace it immediately if it gets damp or dirty.
  • Gently wash the wound each day.
  • Avoid using hydrogen peroxide or iodine on the wound as these may cause skin irritation in some people. Stop using other antiseptic ointments if they cause skin irritation.
  • Do not pick at the skin or the scab, as this can lead to scarring, slow healing, and increase the risk of infection.
  • See a doctor if the wound does not show improvement within 1–2 days.

More severe wound infections require prompt medical attention, particularly those with other symptoms such as fever, feeling unwell, or discharge and red streaks from the wound.

Doctors can treat a bacterial infection with antibiotics. A person must complete the course of antibiotics to treat the infection fully and prevent the bacteria from becoming resistant to the drug.

In addition to cleaning, some wounds may require further treatment. If the cut is large or deep, a doctor or nurse may have to use stitches to close it. They can often close smaller cuts with medical glue or strips of the tape instead.

If the wound contains dead or dirty tissue, a doctor may remove this tissue in a procedure called debridement. Debridement should promote healing and prevent the infection from spreading.

People with animal bites or wounds from dirty or rusty objects may be at risk of tetanus and need to get a tetanus shot.

Tetanus is a potentially fatal condition that occurs when certain bacteria enter the body and release toxins that affect the nerves. The symptoms of tetanus can include painful muscle spasms, lockjaw, and fever.

Cuts, grazes, and other breaks in the skin can become infected when bacteria enter the wound and begin to multiply. The bacteria may come from the surrounding skin, the external environment, or the object that caused the injury.

It is important to clean and protect the wound properly to reduce the risk of infection.

The risk of wound infection is higher if:

  • the wound is large, deep, or has a jagged edge
  • dirt or foreign particles entering the wound
  • the cause of the wound was a bite from an animal or another person
  • the cause of the wound was an injury involving a dirty, rusty, or germ-containing object

Certain health conditions and environmental factors can also increase the risk of infection. These include:

  • diabetes
  • a weakened immune system, such as in people living with HIV or those taking immunosuppressant medications
  • lack of mobility, for example, in people who spend most of their time in bed
  • advancing age — older adults are more at risk of wound infection
  • nutrient and vitamin deficiencies

Rarely, incision wounds from surgical procedures can also become infected. This occurs in about 2-4% of people who undergo surgery.

If a person does not receive treatment for a wound infection, the infection can spread to other parts of the body, which may lead to serious complications, including:

  • Cellulitis is an infection of the deeper layers and tissues of the skin, and it can cause swelling, redness, and pain in the affected area. Other symptoms can include fever, dizziness, nausea, and vomiting.
  • Osteomyelitis is a bacterial infection of the bone, and symptoms include pain, redness, and swelling around the infected area. Fatigue and fever are other symptoms that may affect those with osteomyelitis.
  • Sepsis is an extreme immune reaction that can sometimes occur when an infection enters the bloodstream. Sepsis can lead to multiple organ failures and is life threatening. According to the CDC, nearly 270,000 people in the U.S. die each year due to sepsis.
  • Necrotizing fasciitis is rare when a bacterial infection spreads into a tissue called the fascial lining that lies deep beneath the skin. Necrotizing fasciitis is a medical emergency that causes severe skin damage and pain and can spread throughout the body.

A person with a wound should seek medical attention if:

  • the wound is large, deep, or has jagged edges
  • the edges of the wound do not stay together
  • symptoms of infection occur, such as fever, increasing pain or redness, or discharge from the wound
  • it is not possible to clean the wound properly or remove all debris, such as grass or gravel
  • the cause of the wound was a bite or an injury from a dirty, rusty, or dirty object

A person should seek urgent medical attention if blood is spurting from the wound or if applying pressure to the wound does not stop the bleeding.

How do I tell if my wound is healing or infected?

Signs that a wound is not healing properly and may be infected include feeling warm to the touch, swelling, discharge or pus, long lasting pain, or fever.

Can an infected wound or cut heal on its own?

Some minor wound infections can heal on their own, but if a wound starts to develop more drainage, the surrounding redness spreads, or if a person develops a fever, a person should seek further medical attention.

How do I know if I have necrotizing fasciitis?

When a person has necrotizing fasciitis, they may experience severe pain that worsens with time and experience flu-like symptoms. They may also become dehydrated. A person with these symptoms should seek immediate medical attention. Without prompt treatment, the wound will swell and may become purple. Later, blisters will develop that ooze dark fluid. This is a sign of dying tissue or necrosis. The infection will then spread beyond the initial wound site and become life threatening.

A wound infection can occur if bacteria enter and multiply inside the wound. Immediately cleaning and dressing cuts, grazes, and other small wounds is the best way to prevent infections. However, people with larger, deeper, or more serious wounds should have a trained healthcare professional treat the injury.

The signs and symptoms of wound infection include increasing pain, swelling, and redness around the affected area. A person may be able to treat a mild infection of a small wound at home by recleaning and redressing the wound.

However, more severe wound infections require prompt medical attention, particularly with fever, feeling unwell, or discharge and red streaks from the wound.

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