Necrotizing Fasciitis (flesh-eating disease)

Symptoms are initially mild and generalized. Those who are infected may start off thinking that they have the flu, and there may be dull pain at the site of the wound. However, symptoms progress fast and include:

• Site of infection becomes red and warm
• There is increasing pain at the site of the wound. The pain is in excess of what that kind of injury would normally cause.
• Liquid oozes from the wound or site of injury
• There is bluish or purplish discolouration at the site
• Blisters, bumps, lesions begin to appear
• Fever
• Nausea
• Dizziness
• Fatigue

It is only when symptoms worsen and the wound starts to appear more ominous that people go to the hospital. Because the infection can start from a benign-looking wound, the infection is unlikely to raise any concerns right away.

As the patient's condition worsens, there may be symptoms like:

• Low blood pressure
• Weakness
• Confusion
• Tachycardia or fast heartbeat
• The pain becomes better, as the nerves in the affected area start dying
• The skin starts to turn black
• Delirium
• Loss of consciousness
• The patient stops urinating altogether (anuria)
• Toxic shock

Severe complications and widespread inflammation are common. These include sepsis, shock and organ failure. The infection can be fatal unless treated quickly, and even then there is a high mortality rate.

The infection may be caused by one kind of bacteria or multiple bacteria that usually enter the body through a break in the skin. Some bacteria that cause the infection are present in the gut flora but are not harmful in the gut. Common entryways for the pathogen include:

• Cuts and scrapes
• Surgical wounds. Though this is very rare now due to high safety standards, the infection can be a complication of a surgical procedure such as diagnostic laparoscopy or cardiac catheterization
• Insect bites
• Puncture wounds (such as those made by needles) 
• Burns
• Blunt trauma. In some rare cases, even trauma that doesn’t cause the skin to break can cause the infection.

Apart from Streptococcus P (Group A Streptococcus), some other bacteria that can cause necrotizing fasciitis are Aeromonas hydrophila, Clostridium, E. coli, Klebsiella, Staphylococcus A. and Vibrio Vulnificus, which is present in warm seawater and can enter wounds when someone with a cut or injury goes into the water. 

The infection can be transmitted from one person to another, though this is extremely rare, so close contacts are not given treatment as a precautionary measure. 

While anyone can get the infection, those with diabetes appear to have the highest burden. Their compromised immune system and impaired circulation seem to be the reason for higher risk. 

In extremely rare cases, necrotizing fasciitis can be a side effect of chickenpox in children.

There is no vaccine against necrotizing fasciitis, but general wound care and personal hygiene go a long way in preventing serious infections. Here are some steps you must take to prevent nasty infections: 

• Wash all cuts, scrapes and small wounds with water and soap. 
• Clean open wounds with antiseptic and cover with a clean, dry bandage. Replace the bandage when it becomes worn or moist. 
• Make sure to wash your hands regularly to prevent hand to mouth infections. 
• Do not go to public baths, swimming pools, or lakes if you have open wounds. 

These steps are practical but highly effective and will help you avoid all sorts of pathogens that can cause major disruptions in your life.

There are many diagnostic tools that are used to understand the underlying problem. These include: 

• Physical examination of the injury or infection. If the wound is oozing, and the skin is turning purple and there is severe pain, it may suggest the infection
• A biopsy of the tissue may be done to see what kind of pathogen is involved and to examine the status of the tissue 
• Blood tests will be performed to check for infections and to see if there is muscle damage 
• Imaging tests (CT scan, MRI, ultrasound) of the affected area can be done to check if the infection has spread

It is absolutely crucial to start treatment right away and attack the infection so your doctor will likely not wait for an accurate diagnosis as there won’t be sufficient time. Usually, the signs of a severe infection are apparent given the level of distress and presentation of the wound, but the diagnosis is often difficult in these situations, and a definite answer is only reached on operating on the wound and directly examining tissue.

Treatment will be prompt and will involve clearing the infection as fast as possible. Interventions include: 

• Surgery to remove dead tissue: This is also known as debridement and is done to contain the spread of the infection by getting rid of the source. In severe cases, multiple surgeries will be required if the infection is not cleared, and the affected area may need to be amputated as a last resort.
• An aggressive course of antibiotics: Antibiotics are given along with all other treatments in an effort to kill the bacteria. These will be given intravenously so that they act fast and reach the whole body. However, they may not be effective sometimes if the disease has killed the surrounding tissue—the drugs will not be able to reach the site if this is the case.
• Supportive treatment: Supplemental treatment to make sure vitals are within reasonable bounds. (Read more: What is fluid therapy?)

Treatment may last for some weeks as the patient slowly recovers and regains strength. Reconstructive surgery may be required to improve the appearance and utility of the affected area.