Think twice about hooking up: STD rates are at an all-time high. Worse, the latest STD making the rounds could literally make your genitals rot off. Donovanosis, also known as granuloma inguinale, is a sexually transmitted infection that turns a person’s genitals into flesh-eating ulcers. It can also infect the mouth, nose, and chest.

The disease has typically been reported in warm, humid regions including India, southern Africa, central Australia, and the Caribbean, but cases have also appeared in cooler climates. The CDC records about 100 cases in the U.S. each year. This summer, the U.K. saw a rash of cases as well.

“This is a very rare and nasty condition and it could be one of the first times it has been recorded in the U.K. Any delay [in treatment] could cause the flesh around the genitals to literally rot away,” said pharmacist Shamir Patel. “This bacteria is also a risk factor in the transmission of HIV.”

The condition is transmitted during sexual contact with an infected person, but symptoms don’t appear until after a 17-day incubation period, which means an infected person could unknowingly spread the STD to other partners. It can take up to 12 weeks after contact with an infected person for the disease to reveal itself.

The first sign is typically a firm, bleeding sore. Donovanosis may exist alongside other STD infections, including syphilis and HIV, and in some cases has been associated with cancer and complications in pregnancy. The good news: The bacterial infection is treatable with antibiotics such as azithromycin, doxycycline, ciprofloxacin, erythromycin, and trimethoprim-sulfamethoxazole, if caught early enough, and if the bacteria don’t develop antibiotics resistance, as has happened with gonorrhea. However, relapses can occur.

Fun fact: There are actually four versions of the disease. The most common is the ulcerograulomatous type, which is characterized by single or multiple fleshy ulcers which may bleed upon touching. More unsightly is the verrucous (or hypertrophic) type, in which the ulcers feature raised, irregular edges, and a dry, walnut-like appearance. The sclerotic (or cicatricial) type results in the formation of fibrous and scar tissue. Most disturbing is the necrotic type, in which the ulcer is deep and foul-smelling and results in the destruction of flesh in the surrounding areas.

In women, donovanosis tends to affect the labia minora and vulva. In men, the usual sites of infection are prepuce, frenulum, coronal sulcus and glans penis. Uncircumcised men are at greater risk of acquiring this condition, and men are twice as likely to become infected.

“It can present itself as one or more nodules under the skin that later break down to form ulcers, typically in the genital or groin regions. The ulcers enlarge, easily bleed, and have raised edges. For men it can be noted along the shaft, under the foreskin and around the anus. Women typically have lesions on the labia and occasionally on the cervix and vagina. If untreated, they can become quite extensive and can lead to scarring,” said Dr. Michelle Bailey.

This flesh-eating STD is not to be confused with necrotizing fasciitis, the best-known flesh eating disease, which can be caused by bacteria like group A Streptococcus, staphylococcus, Vibrio vulnificus, or Clostridia. Necrotizing faciitis can spread rapidly, leading to loss of body parts and even death. 

How can you avoid losing or damaging your genitals in a painful bout of rotting disease? Use a barrier protection method such as a condom. (In Australia, however, a few cases have been spread via non-sexual contact.)

Donovanosis isn’t the only flesh-eating condition that affects the genitals. Another one, Fournier’s gangrene, has a similar progression. Fournier’s gangrene is an infection in the scrotum, penis, or perineum. It is a rare but life-threatening bacterial infection of the tissue under the skin that surrounds muscles, nerves, fat, and blood vessels. It most often infects men between the ages of 50 and 60. Men are 10 times more likely than women to have Fournier’s gangrene.

The bacteria usually get into the body through a cut or break in the skin, where they quickly spread and destroy the tissue they infect. “It can start with a nick to a hair follicle during shaving,” says Dr. Brian Steixner, M.D., Director of the Institute of Men’s Health at Jersey Urology Group in Atlantic City. “A very specific bacteria gets under the skin, and it travels fast. It basically starts to eat away at all the skin."

Horrifyingly, people can contract Fornier’s through their diabetes medication. The FDA has released a warning about sodium-glucose cotransporter-2 (SGLT2) inhibitors, medication used treat type 2 diabetes. But it’s extremely rare.

“Seven cases out of 7 million prescriptions,” said Gary Scheiner, MS, CDE, founder of Integrated Diabetes Services, author of “Think Like a Pancreas,” and a 2014 diabetes educator of the year. “That makes it literally a one-in-a-million event.”

Whew.