Illness is widespread; while many of us have only experienced mild illnesses like the flu, there are countless strange and deadly diseases waiting to strike. But some diseases don’t just take your life—they aim to disfigure you in the process. Below are ten of the most gruesome diseases ever endured by humankind.
10. Phossy Jaw

Fortunately, this disease has been consigned to the past. In the 1800s, workers in the match industry were exposed to large amounts of white phosphorus, a toxic substance that caused excruciating pain in their jaws. Over time, the jaw would become infected, filled with pus, and eventually decay. The bone emitted a foul smell and even glowed in the dark. If untreated, the phosphorus would spread to the organs, leading to death.
9. Proteus Syndrome

One of the most uncommon conditions on Earth (only around two hundred cases have been documented), Proteus Syndrome is a birth defect that causes different parts of the body to grow uncontrollably. Asymmetrical bone and skin tumors often appear on the skull and limbs, particularly on the soles of the feet. There's a theory suggesting that Joseph Merrick, the so-called “Elephant Man,” may have had Proteus Syndrome, although DNA testing has yielded no definitive results.
8. Acromegaly

Acromegaly occurs when the pituitary gland overproduces growth hormone. This is typically caused by a benign tumor affecting the gland, resulting in abnormal growth well beyond the point where the body is supposed to stop growing. Along with the increase in size, individuals with acromegaly often develop a distinct look: a prominent Neanderthal-like brow, widely spaced teeth, and an underbite. One of the most notable people with acromegaly was Andre the Giant, who, at his peak, stood seven feet four inches tall (2.2m) and weighed over five hundred pounds (225kg). If untreated, the body continues to grow until the heart can no longer support the size, as it did in Andre, who died from heart disease at the age of forty-six.
7. Leprosy

Leprosy, a disease caused by bacteria, has been around for thousands of years. It progresses slowly, with ulcers appearing on the skin and expanding until it looks as though the body is decaying. The disease tends to affect the cooler regions of the body, including the face, hands, feet, and genitals. While entire limbs don’t typically fall off, it’s common for sufferers to lose fingers, toes, and even parts of their nose, resulting in a grotesque appearance with gaping holes. For centuries, those afflicted by leprosy were ostracized from society, and even today, leper colonies exist across the globe.
6. Smallpox

Smallpox, an ancient disease, has been found on Egyptian mummies, though it was officially declared eradicated in 1979. Roughly two weeks after contracting the disease, victims are covered in a painful rash of bloody, oozing lesions resembling large pimples.
If you’re fortunate enough to survive, the lesions eventually dry up, but they leave behind severe scarring. Historical figures such as George Washington and Abraham Lincoln both survived smallpox, and Soviet leader Joseph Stalin had a particularly bad case. He was so self-conscious about the pockmarks on his face that he would have photographs altered.
5. Epidermodysplasia Verruciformis

A highly rare skin condition, Epidermodysplasia verruciformis is marked by an extreme vulnerability to the human papilloma virus, leading to the growth of grotesque, tree-bark-like warts all over the body. The world became aware of this horrific disorder in 2007, when the case of Dede Koswara, who had a similar condition, gained attention online. Dede was featured on both Discovery Channel and The Learning Channel. He has undergone numerous surgeries to remove his warts, sometimes having several pounds of them removed at once. Sadly, the warts from both diseases are highly aggressive and grow back immediately. It is estimated that Dede will require at least two surgeries a year to maintain a somewhat normal appearance.
4. Porphyria

Porphyria is a hereditary genetic disorder that leads to a buildup of porphyrins, which are organic compounds that have various roles in the body, such as aiding in the production of red blood cells. Porphyria affects the entire body, especially the liver, and can cause a variety of mental health issues. Individuals with cutaneous porphyria must avoid sunlight, as exposure causes their skin to swell and blister. It is believed that the appearance of those with porphyria may have contributed to the creation of vampire and werewolf legends.
3. Necrotizing Fasciitis

Minor cuts and scrapes are a common part of life, and usually, they are nothing more than a minor nuisance. However, in the presence of flesh-eating bacteria, even the smallest of wounds can become life-threatening within hours. While the bacteria do not literally “eat” the flesh, they release toxins that rapidly destroy tissue. Treatment involves the administration of large quantities of antibiotics, and all infected tissue must be removed to prevent the spread of the infection. In severe cases, surgeries may result in amputations or other disfiguring procedures. Despite medical intervention, necrotizing fasciitis is fatal in 30-40% of all cases.
2. Elephantiasis

Elephantiasis is a grotesque condition caused by the bacteria found in parasitic worms or by exposure to irritant alkali soils. It leads to severe swelling and thickening of the skin in the legs and groin. Common in tropical regions, especially Africa, over one hundred million people suffer from this debilitating disease.
The swelling is caused by the body’s immune system trying to combat the disease, leading to severe pain in the affected area, along with headaches and nausea. There is no cure, though certain antibiotics have shown promise in alleviating symptoms. In the most extreme cases, surgery or even amputation may become necessary.
1. Cutaneous Leishmaniasis

Found worldwide, especially in warmer regions, the sandfly is a bloodsucking insect similar to a mosquito. Unfortunately, this insect does not just take blood—it sometimes leaves behind a parasitic infection. What begins as a small bite soon becomes a painful, festering ulcer. Sandflies often target the face, and untreated bites can take months to heal. In Afghanistan, where they are especially prevalent, these bites are known as 'one-year sores'.