Gangrene

Original Editor - Kirenga Bamurange Liliane Top Contributors - Kirenga Bamurange Liliane, Kim Jackson, Lucinda hampton, Cindy John-Chu and Nupur Smit Shah

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Introduction

Gangrene is the death of body tissues due to the loss of blood. It can be caused by illness, injury, or infection and usually happens in extremities like fingers, toes, and limbs. Gangrene can also occur in your organs and muscles .

Symptoms

Signs and symptoms of gangrene may include the following:

• Skin discoloration which can be from pale to blue, purple, black, bronze or red, depending on the type of gangrene you have
• Swelling
• Blisters
• Sudden, severe pain followed by a feeling of numbness
• A foul-smelling discharge leaking from a sore
• Thin, shiny skin, or skin without hair
• Fever and feeling unwell depending on the type of gangrene

A few symptoms can be red flags and start before gangrene starts:

• Rest pain
• Pallor of extremities on elevation
• Poor capillary filling
• Thickening or scaling of the skin

Types of Gangrene

There are two main types of Gangrene:

1. Dry Gangrene

Dry gangrene is frequently observed among patients who have vascular disease, diabetes, and autoimmune diseases. It usually affects the hands and feet and happens when there is poor blood circulation to a certain area. Therefore, the tissue that dries up changes color and can either turn brown, purplish-blue, or black before the tissue can fall off. There is no infection associated with dry gangrene, but it can lead to wet gangrene if infected. Dry gangrene has a slow progression.

2. Wet Gangrene

Wet gangrene is a condition that involves infection and affects moist tissues such as respiratory tissues, oral tissues, cervix, and vulva. Swelling and blistering of the tissue are observed. An infection from wet gangrene can rapidly spread swift around the body. For a patient with a history of foot ulcer or tissue injury post diabetes or ischemia, the presence of drainage and edema should be a red flag for a wet gangrene diagnosis. Moreover, a thorough evaluation of the foot is needed to rule out any presence of deep foot abscess that comes with a plantar tenderness . Wet gangrene can progress from dry gangrene as the necrotic tissue becomes infected. In this case, it is therefore accompanied by an edematous and erythematous tissue surrounding the necrotic area .

The different types of Wet gangrene include:

• Internal gangrene affects internal organs such as the appendix or colon most of the time.
• Gas gangrene is a rare, dangerous, and life-threatening condition. It is due to an infection inside the body. If left untreated, gas gangrene can cause death within 48hrs .
• Fournier's gangrene is also a rare condition caused by an infection of the genital area. When the infection gets into the bloodstream, it is referred to as sepsis and is life-threatening. This type of gangrene affects more often men than women.
• Meleney's gangrene usually causes painful lesions on the skin one or two weeks post-surgery or minor trauma.

Risk Factors

There are conditions that affect the blood flow supply and therefore increase the risk of getting gangrene. They include:

• Diabetes
• Arteriosclerosis
• Severe injury or surgery
• High cholesterol
• Smoking
• Obesity
• Weakened immune system
• Injected medications or drugs
• Raynaud's Phenomenon
• Complications of COVID-19

Diagnosis

The diagnosis of gangrene is primarily clinical with medical history of the patient taken and physical examination done. Moreover, further tests can be done for a confirmatory diagnosis. These are:

• Blood Tests to look for bacteria or signs of infection.
• Imaging Tests such as MRI and CT scan to see if it gangrene has spread and rule out any gas build up in the tissues.