By Jayne Leonard

Reviewed by Alana Biggers, MD, MPH

A wound infection occurs when germs, such as bacteria, 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.

In this article, we describe how to prevent, recognize, and treat an infected wound. We also cover risk factors, complications, when to see a doctor, and medical treatment.

How to recognize a wound infection

People can usually safely treat small wounds, such as minor cuts and scratches, at home. With proper care, most small wounds will gradually get better until they fully heal.

If a wound becomes infected, however, it can get worse instead of better. Any pain, redness, and swelling will typically increase in intensity.

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
• vomiting

Treating infected wounds at home

People with a mild infection of a small wound may be able to treat the wound at home. However, more severe wound infections require prompt medical attention, particularly those that occur along with other symptoms, such as fever, feeling unwell, or discharge and red streaks coming from the wound.

To treat an infected wound at home, follow these steps:

1. Before beginning, 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. 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.
4. Make sure that there is no dirt or debris, such as glass or gravel, in the wound. To remove debris, either use tweezers or carefully and gently rub the wound with a soft, damp cloth.
5. If desired, apply a thin layer of antiseptic ointment or petroleum jelly to the cut or scrape.
6. 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.

Other tips for treating wounds at home include:

• 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 down healing, and increase the risk of infection.
• If the wound does not show signs of improvement within 1–2 days, see a doctor.

How to prevent wound infection

Cleaning and protecting a wound can reduce the risk of infection. After sustaining a minor cut or scratch, a person should:

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.

People with larger wounds or excessive bleeding will require medical treatment. A healthcare professional can treat the injury to prevent infection and other complications.

People with animal bites or wounds from dirty or rusty objects may be at risk of tetanus and should also seek medical attention. A healthcare professional can clean the wound and give the person a shot to protect against tetanus infection if necessary.

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.

Risk factors

Cuts, grazes, and other breaks in the skin can become infected when bacteria enter the woundand 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 entered 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 contaminated object

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

• diabetes
• poor blood circulation
• a weakened immune system, such as in people living with HIV or those taking immuno suppressant 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. According to the Centers for Disease Control and Prevention (CDC), between 2006 and 2008, about 1.9 percent of surgical wounds became infected in people having operations in the United States.

Complications

If a person does not receive treatment for a wound infection, it 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, and 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 failure 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 a rare condition that occurs 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.

When to see a doctor

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 glass or gravel
• the cause of the wound was a bite or an injury from a dirty, rusty, or contaminated object

Seek urgent medical attention if blood is spurting from the wound or if applying pressure to the wound does not stop the bleeding.

Medical treatment

Doctors can treat a bacterial infection with antibiotics. It is important for a person to complete the course of antibiotics to treat the infection fully and to 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, for example, a doctor or nurse may have to use stitches to close it. They can often close smaller cuts with medical glue or strips of tape instead.

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

A person might require a tetanus shot if the cause of the wound was a bite or an injury from a dirty or rusty object.

The CDC recommend that adults get a tetanus booster shot every 10 years to protect them against tetanus infection. However, for certain types of wound, a doctor may still prescribe a tetanus shot for people who have not had one in the past 5 years.

Summary

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 can 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 those that occur along with fever, feeling unwell, or discharge and red streaks coming from the wound.