The phrase “flesh-eating STD” is trending. You might’ve seen it in headlines or TikToks. It sounds dramatic, and honestly, scary. But it’s not a real medical term.

There isn’t a single sexually transmitted infection that eats flesh. What people are referring to is a mix of different conditions. Some are STDs. Some aren’t. A few can cause serious tissue damage if left untreated.

This article explains what’s behind the name. We’ll break down three main conditions: donovanosis, Fournier’s gangrene, and necrotizing fasciitis. One is an STI. The others are not, but they sometimes show up in sexual health discussions.

We’re not here to scare you. The goal is to explain what’s real, what’s exaggerated, and when you should see a doctor.

What Is a “Flesh-Eating” Infection?

“Flesh-eating” is not a medical term. It’s something the media uses to describe infections that destroy skin and soft tissue.

The proper name is necrotizing infection. “Necrotizing” means the tissue is dying. These infections spread fast. They usually need emergency treatment. In some cases, surgery is the only way to stop them.

These infections are caused by bacteria. They can enter through cuts, ulcers, or surgical wounds. Some types include:

• Necrotizing fasciitis – spreads along muscle lining under the skin
• Fournier’s gangrene – affects the genitals and perineum
• Donovanosis – an STI that can break down genital skin if untreated

Only one of these is sexually transmitted. But because the others affect the genital area, people often confuse them. That’s how the “flesh-eating STD” label started.

Donovanosis: The STI That Gets Misnamed

Donovanosis is a real sexually transmitted infection. It’s caused by a bacteria called Klebsiella granulomatis. It spreads through unprotected vaginal, anal, or oral sex.

The main symptom is a painless lump on the genitals. That lump turns into an open sore. The sore doesn’t go away on its own. It gets bigger, and in some cases, it destroys the surrounding skin. This is why it’s sometimes called “flesh-eating.” But the bacteria aren’t eating anything. It’s just an untreated infection that’s breaking tissue down.

Donovanosis is rare. It’s mostly found in parts of India, Papua New Guinea, Southern Africa, and Central Australia. But a few cases have been reported in the UK and US in recent years. Some clinics in Singapore have seen imported cases, especially among people returning from travel.

The good news? It’s curable. Antibiotics like azithromycin or doxycycline can stop it. But early treatment is key. Left alone, the sores can get worse and cause long-term damage.

If you notice unexplained genital ulcers, especially ones that grow or don’t heal, get tested. STD testing is quick and private. Don’t wait.

Fournier’s Gangrene: Not an STD, But Still Serious

Fournier’s gangrene is not sexually transmitted. But it affects the genital and perineal area, so it often shows up in sexual health conversations.

This condition is a type of necrotising fasciitis. It usually starts when bacteria enter through a break in the skin — maybe from shaving, a small injury, or a sore. The infection spreads quickly and kills the surrounding tissue. It can lead to swelling, pain, skin discolouration, and a bad smell. Fever and fatigue are common too.

It’s more common in people with diabetes, poor circulation, or weak immune systems. Men are affected more often than women, but anyone can get it. It can develop after surgery, trauma, or even something as simple as a scratch that gets infected.

Some reports link Fournier’s gangrene to sexual activity, especially if there’s rough contact, toys, or hygiene issues. But the condition itself isn’t caused by sex. It’s caused by common bacteria that get into the wrong place.

Fournier’s needs emergency care. Treatment usually involves strong IV antibiotics and surgery to remove damaged tissue. Without fast treatment, it can be deadly.

Necrotizing Fasciitis and Sex: What’s the Link?

Necrotizing fasciitis, or NF, is one of the most serious skin infections. It spreads fast and can affect any part of the body. Most of the time, it starts after trauma or surgery. It’s not an STD.

But in rare cases, NF has been reported after sex. This can happen if there are small tears in the skin, poor hygiene, or exposure to bacteria during sexual contact. Some cases have involved infections in the vulva or perineum. A few were linked to sex toys, anal contact, or infections that entered through small cuts.

The bacteria that cause NF are often ones you’ve heard of  like group A strep, E. coli, or MRSA. These bacteria usually live on the skin or in the gut. They’re not sexually transmitted, but they can become dangerous if they get deep under the skin.

Symptoms show up fast. Pain gets worse quickly. The skin may turn red, swollen, or black. Fever and weakness usually follow. This is a medical emergency.

If you notice severe pain, fast-spreading redness, or any signs of tissue damage after sex or otherwise, go to the emergency room. Don’t wait to see if it gets better.

So… Is There a Flesh-Eating STD?

No. There is no medical condition called a “flesh-eating STD.” It’s not a diagnosis. It’s a label that’s been used in headlines and on social media to describe a few different infections.

Donovanosis is the only one that qualifies as an STI. It can cause skin ulcers that get worse over time. But it doesn’t eat flesh. It just spreads if not treated.

Fournier’s gangrene and necrotizing fasciitis are different. They involve severe tissue damage, but they’re not sexually transmitted. They’re caused by bacteria that enter through cuts or weak points in the skin. In rare cases, they can affect the genitals after sex. But they don’t spread through sexual contact like HIV or chlamydia do.

So when someone says “flesh-eating STD,” they might be thinking of one of these three conditions. But using that term causes confusion. It sounds like one superbug, when it’s really a few separate infections, and only one is an STI.

What to Look Out For: Symptoms That Matter

Not every sore or rash is serious. But some signs shouldn’t be ignored. If you notice any of the following, see a doctor right away:

• Open sores on the genitals that grow or won’t heal
• Redness that spreads quickly
• Severe pain, even if the skin looks normal
• Swelling or skin that feels warm or hard
• Bad smell or discharge
• Fever, chills, or feeling weak

Most of the time, infections that involve the genitals are easy to treat if caught early. Waiting makes things worse.

If you’re worried about an STI, go for STD testing. If the symptoms are severe or spreading fast, don’t wait. Go to a doctor or emergency clinic immediately.

Treatment: Why Fast Action Matters

These infections don’t fix themselves. The longer you wait, the more damage they can cause. In some cases, they can be life-threatening.

Donovanosis

This is the only one on the list that is sexually transmitted. It’s treated with antibiotics. Doctors usually prescribe azithromycin or doxycycline. Treatment can take a few weeks. The sores usually heal without scarring if caught early.

Fournier’s Gangrene

This is an emergency. It needs hospital care, intravenous antibiotics, and often surgery to remove damaged tissue. Some people need multiple operations. Recovery can take time, but early action saves lives.

Necrotizing Fasciitis

This is also an emergency. Doctors treat it with strong antibiotics and surgery. Sometimes people need ICU care or skin grafts. Early diagnosis makes a huge difference.

If you’re unsure what’s going on, don’t self-diagnose. Get checked. Even if it’s something minor, ruling out serious infections early can give peace of mind and prevent complications.

Facts Over Fear

There’s no such thing as a flesh-eating STD. But there are infections that affect the genitals and can become dangerous if ignored. One of them, donovanosis, is an STI. The others are not, but they’re sometimes linked to sex through hygiene or skin exposure.

Headlines often blur these details. That creates fear, but not clarity. The real takeaway is this  – if something feels wrong, get it checked. It doesn’t have to be dramatic to matter. Early treatment is almost always easier, cheaper, and more effective.

Shim Clinic offers discreet, walk-in consultations for anyone with STI concerns. You don’t need to know what’s wrong to get started. If you notice changes, talk to someone. We’re here to help, not judge.