When Juicing Limes in the Sun Goes Horribly Wrong

It turns out there’s more than one bad kind of “lime disease.” In a recent report, doctors detail a man who got nasty rashes and blisters on his hands after he juiced a bunch of limes—limes that had made his skin especially vulnerable to the Sun’s harmful ultraviolet radiation.

The man’s doctors reported the case last week in the New England Journal of Medicine, as part of a regular segment highlighting images of unusual injuries or illnesses. The 40-year-old man went to an allergy clinic two days after he started having a burning rash that ran alongside both hands, particularly the fingers, and a blister on his left thumb. It apparently didn’t take long for the doctors to diagnose him once they learned that a day before his rash began, he had manually juiced 12 limes and then spent the day outside watching a soccer game. The man had developed a classic case of phytophotodermatitis (for those with a strong stomach, the man’s hands can be viewed here).

Phytophotodermatitis is triggered by a combination of two things: exposure to a class of chemicals commonly found in plants and fruits known as furanocoumarins, followed by exposure to ultraviolet A radiation. The furocoumarins are absorbed into the skin and sensitize it to UVA, causing an inflammatory reaction that kills off skin cells—albeit one that doesn’t involve the immune system. Unlike a sunburn, it can take a day or two for the symptoms of phytophotodermatitis to appear following exposure, though the rash usually isn’t itchy at least.

Citrus fruits like lemon and limes are a typical culprit of phytophotodermatitis—so much so that doctors really have nicknamed the condition lime disease, while others have coined it “margarita burn.” Figs, celery, parsley and other culinary plants can cause the condition as well. Funny as it sounds, the condition is dangerous if it causes gaping skin wounds to form, since these leave the door open to secondary skin infections.

Unfortunately, there’s no easy recourse for phytophotodermatitis once it happens; you simply have to wait for it to fade away on its own, which can take weeks to months. That said, doctors can prescribe topical treatments to alleviate symptoms or the risk of infection.

In this case, the man was given a topical steroid cream and moisturizer for his affected skin. He did later develop a second blister and scaly skin, but his hands eventually returned to normal after several months. Things could have gone way worse for him, too, since the condition has been known to cause hyperpigmented scars that take years to clear up. Some people have also speculated that phytophotodermatitis (particularly cases triggered by exposure to the giant hogweed plant) can cause blindness, though it appears no actual reports of this complication have ever been documented.