What is gangrene?
Gangrene is a serious medical condition in which lack of blood supply to body tissues causes the tissue to die. Although any body tissues can be affected, gangrene most commonly starts in the fingers, toes, hands and feet.
Gangrene can be fatal if left untreated.
There are several different types of gangrene including:
- Dry gangrene: Tissue death results when blood flow to an area is disrupted or becomes blocked, often due to poor circulation.
- Wet gangrene: Tissue death results from a bacterial infection and injury that cuts off the blood supply. Tissue swells, blisters, and pus (the “wet” factor) develops. Wet gangrene can quickly spread and therefore requires immediate medical attention.
- Gas gangrene: Tissue death results from an infection caused by the bacteria Clostridium. The bacteria quickly multiply inside body tissues, forming toxins and releasing gas in the tissue. If left untreated, gas gangrene can quickly lead to death.
- Fournier’s gangrene: This gangrene is caused by an infection to the penis, scrotum or perineal (genital and anal) area.
- Internal gangrene: This gangrene is due to blocked blood flow specifically to internal organs, such as the intestines, gallbladder or appendix.
Who is at risk for gangrene?
Gangrene is more likely to develop in individuals who have:
- Atherosclerosis or peripheral arterial disease: In these conditions, fat deposits in the arteries restrict blood flow.
- Diabetes: Diabetes damages nerves and blood vessels. Diabetes causes wounds to heal more slowly. Slow healing wounds are at increased risk for infection. Feet are especially at risk for infection as a complication of diabetes.
- Raynaud’s syndrome: In this condition, blood vessels in the fingers and toes react abnormally to cold temperatures. The blood vessels constrict (narrow) causing a decrease in blood flow to these digits.
- Serious injuries to skin and tissues – such as from burns, frostbite, trauma (e.g. resulting in a crushed or squeezed body part): These injuries cause loss of blood to the area, tissue damage and increased risk of infection.
- Weakened immune system: Even minor infections can lead to gangrene in individuals with weakened health status (for example, from such causes as diabetes, cancer, infectious diseases, alcoholism/drug abuse, older age).
Symptoms and Causes
What causes gangrene?
Gangrene is tissue death that results from lack of blood supply to the affected tissue area. Blood flow to all of the body’s tissues is vital to life. Blood delivers oxygen, nutrients and antibodies to fight infection. If the blood supply is cut off, cells can die, infections can develop, and tissue can die from gangrene.
Gangrene occurs as a result of an injury, infection in tissue or other conditions that affect blood circulation.
What are the signs and symptoms of gangrene?
The symptoms of gangrene vary depending on the cause. General symptoms include:
- Cold, pale skin.
- Loss of feeling in the affected area.
- Pain may or may not be present in the affected area.
- Red and swollen skin in the affected area.
If a bacterial infection causes gangrene, other signs and symptoms may also include:
- Loss of appetite.
- Rapid breathing and heartbeat.
- Severe pain in the affected area.
- Sores and blisters that bleed and release foul-smelling pus.
- Crackling sound when pressing on the skin (indicates a buildup of gas in tissue).
- Change in skin color as it dies -- from red to brown to purple to black.
Diagnosis and Tests
How is gangrene diagnosed?
Your doctor diagnoses gangrene by examining your skin, taking your medical history and ordering tests, including:
- Circulation studies to check blood flow to the affected area of the body.
- Blood work to check for infection.
- Blood, fluid, or tissue cultures to determine the specific bacteria involved (if bacteria are involved) and best antibiotic to treat the bacterial infection.
- Imaging tests, such as computed tomography (CT) or magnetic resonance imaging (MRI), to confirm gangrene location and spread, identify gas gangrene, identify blockage of blood flow.
- Surgery to confirm gangrene and to treat it.
Management and Treatment
How is gangrene treated?
The goals of gangrene treatment are to:
- Remove dead or infected tissue.
- Prevent or treat infection to keep gangrene from spreading.
- Treat the underlying conditions that caused gangrene to develop.
Removing dead tissue
Dead tissue can be removed through traditional surgery or by a type of biosurgery called larval debridement therapy. This type of therapy uses maggots that do not reproduce. These laboratory-bred maggots are placed on the wound, which is then covered with a dressing. The maggots feed on dead tissue only; leaving healthy tissue alone. After a few days, the dressing and maggots are removed.
Amputation of the affected finger, toe or limb is sometimes the only option if gangrene is severe and removal of the dead tissue is unlikely to prevent its spread.
Restoring blood flow
In some cases, doctors surgically repair blood vessels. The repaired vessels allow blood flow to reach the area affected by gangrene so that the tissue can recover and to prevent gangrene from occurring again.
Treating the infection
If a bacterial infection causes gangrene, doctors prescribe antibiotics to treat and prevent infection.
Other treatments such as hyperbaric oxygen therapy (HBOT) may also be used. During HBOT, you are enclosed inside a high-pressure oxygen chamber. High levels of oxygen circulate through body tissues, helping to heal dying tissue. The high oxygen content may also help decrease bacterial growth that relies on oxygen to grow and spread.
What complications are associated with gangrene?
Left untreated, gangrene may progress to a serious blood infection called sepsis. Sepsis may cause complications including organ failure, extremely low blood pressure, changes in mental status, shock and death.
Can gangrene be prevented?
For people living with circulatory system issues or diabetes, the best way to prevent gangrene is to keep blood glucose levels within the normal range and to regularly check your feet and legs for any signs of injury or skin breakdown. Early diagnosis of these problems allows treatment to begin before gangrene develops.
Other ways to help prevent gangrene include quitting smoking, avoiding alcohol, eating a healthy diet and exercising regularly.
Outlook / Prognosis
What is the prognosis (outlook) for people with gangrene?
The prognosis for people with gangrene depends on the cause. Early diagnosis and treatment are the keys to a successful recovery.
When should I call my doctor?
Contact your doctor if you have a wound or infection that gets progressively worse, or if you experience any of the symptoms of gangrene. Early treatment helps prevent serious complications.