9 signs of a 'flesh-eating' bacteria infection after an injury or surgery that mean you need to see a doctor immediately

• Georgie Henley recently spoke out about the scars she has from a brush with necrotizing fasciitis.
• The "flesh-eating" infection is known to spread quickly and can result in amputation or death.

Necrotizing fasciitis — also known as "flesh-eating" bacteria infection — tends to escalate quickly. A slightly swollen scrape can turn into an oozing ulcer within hours, and it can be life-threatening if the infection is left untreated.

Georgie Henley, who played Lucy in "The Chronicles of Narnia" movies, shared in an Instagram post on Tuesday that she almost lost her left arm to a "flesh-eating" infection when she was 18.

The 27-year-old said she needed extensive surgeries to avoid losing her arm, plus operations to reconstruct the infected area with skin grafts. She hid her surgical scars for years before she felt comfortable posting a photo, Henley said.

The bacteria that cause necrotizing fasciitis can enter the body through any break in the skin — even something as small as an insect bite, according to the US Centers for Disease Control and Prevention. Cuts, scrapes, burns, puncture wounds, and surgical incisions can also become infected with dangerous bacteria.

More rarely, people can get necrotizing fasciitis after a bruise or trauma that does not break the skin.

"Flesh-eating" bacteria are known to spread quickly, so it's important to seek medical attention if you notice the early symptoms of the infection, the CDC states. Here are some signs to look out for.

Early signs can look like a minor infection

The symptoms of a "flesh-eating" bacteria infection can be confusing at first, but they will escalate quickly, according to the CDC.

Early symptoms of necrotizing fasciitis can include:

• A red, warm, or swollen area of skin that spreads quickly
• Severe pain, including pain beyond the area of the skin that is red, warm, or swollen
• Fever

It is important to see a doctor right away if you notice any of these symptoms after an injury or surgery, before the infection has a chance to spread, the CDC says. The symptoms could also indicate a more minor infection, but the CDC says people shouldn't delay getting medical care.

Speedy treatment is key to stopping the infection from spreading, so doctors may go ahead with treatment before test results confirm a necrotizing fasciitis diagnosis. Treatment typically involves antibiotics and surgery to remove the infected tissue.

Symptoms may progress to oozing and discoloration

Necrotizing fasciitis earned the name "flesh-eating infection" because the bacteria involved quickly kill infect tissue, "eating" through the skin.

If left untreated, the infection will worsen at a life-threatening pace. As many as one in five cases of necrotizing fasciitis are fatal, according to the CDC.

Signs that a flesh-eating infection has progressed include:

• Ulcers, blisters, or black spots on the skin
• Changes in the color of the skin
• Pus or oozing from the infected area
• Dizziness
• Fatigue (tiredness)
• Diarrhea or nausea

The CDC recommends cleaning and bandaging even the most minor injuries to avoid an infection, "flesh-eating" or otherwise. Steer clear of hot tubs, swimming pools, and natural bodies of water until the wound has healed, the CDC says.