(CNN)Sweating blood from her face and the palms of her hands, a 21-year-old woman was admitted to an Italian hospital. Drs. Roberto Maglie and Marzia Caproni, both dermatologists at the University of Florence, reported the case Monday in the Canadian Medical Association Journal.
The patient, whose identity remains anonymous as is customary in case studies, had no signs of scratches or wounds. Her spontaneous bleeding episodes had no obvious trigger and each instance lasted anywhere from one to five minutes and then ended on its own.
Sometimes the bleeding occurred while the young woman was sleeping, at other times, while she was exercising or physically active. The patient had endured the condition for three years.
Embarrassed by the ghoulishness of her symptoms, the young woman had socially isolated herself and experienced symptoms of major depression, as well as panic disorder.
Analysis of her skin where the bleeding had occurred showed nothing unusual. Tests of her blood revealed no coagulation issues or other problems.
Maglie did not respond to a request for comment. According to the journal, Maglie and Caproni diagnosed hematohidrosis, a rare disease marked by spontaneous discharge of "blood sweat" through intact skin. The doctors first treated her depression and panic symptoms with an antidepressant, paroxetine, and an anti-anxiety medication, clonazepam. Next, they prescribed propranolol, a beta blocker prescribed to patients with heart conditions, a drug which had been used in similar cases in the past. This treatment reduced her bleeding, but did not end it.
"I believe the case is real," said Dr. Jacalyn Duffin, a retired hematologist, and a medical historian and professor at Queen's University in Ontario.Though Duffin did not treat or write about the patient, she explored the history of sweating blood cases and this particular case in an editorial published this week in the same journal.
Skepticism overcome by facts
Duffin traced the earliest mention of sweating blood back to Aristotle's writing in the third century B.C. In two instances, the Greek scientist and philosopher described sweat that either looked like, or really was, blood.
Reading about "lots of cases all around the world," Duffin said they shared surprising similarities in the way they occurred and how they happened. "The more research I did historically, the more I realized these people didn't know each other ... and so they couldn't be inspired by each other," said Duffin. These individual cases, then, could not be attributed to copycat behavior.
In the accounts she read, the most common sites for sweating blood were the forehead, scalp, face, eyes and ears. "Some of them have had it on their trunk, some on their limbs -- it appears it can be anywhere," said Duffin.
Pain or tingling preceded some instances of sweating blood, while several patients experienced headaches or hypertension. Sweating blood is not exclusive to females, but most patients were women.
"Although it's horrible to look at and horrible to suffer, it seems not to be associated with negative [health] outcomes," said Duffin, adding that none of the patients reported in modern times had died of it.
Most patients, like the Italian woman, experience distress. A couple of the patients Duffin read about were infants. "I'm not sure that the infants experienced distress, but certainly their parents do," she said.
"It's terribly embarrassing and when nobody seems to know what causes it, it's very frightening to have it," said Duffin. "Doctors are perplexed and yet it's so obvious and scary looking."
The medical confusion is not for a lack of trying to understand this condition and its cause.
"In all the cases that were published, the blood was tested and there was no coagulation problem -- including in the case today," said Duffin. "Because the first thing you think is, 'Oh, they're a bleeder, they have a bleeding disorder.' There was nothing wrong with their blood, so that implies there's something wrong with their skin."
There, too, the evidence was inconclusive. In some cases, blood appears in the sweat ducts, yet the ducts of other patients remain clean of blood. Skin biopsies appear normal.
While theories abound, none have been proven, said Duffin.
"It could be that this phenomenon of having blood appear on your face could have multiple different causes," she said, having speculated herself on the condition's physiological origins.
In some cases, she noted, patients have experienced a terrible fright before the bleeding starts. "Suddenly your adrenaline goes up and if your adrenaline goes up, maybe it does something to the microvasculature -- your tiny capillaries -- in your skin that causes them to shrink or explode," suggested Duffin. This unproven scenario could be one cause of bleeding skin.
"Or perhaps it's an inherited fragility of the blood vessels in the skin," said Duffin. "Or maybe it's triggered by some chemical we don't know about."
"What we learned from the cases I reviewed in the literature, it can spontaneously remit -- in other words it can just vanish with no explanation," said Duffin. "It comes with no explanation and it goes with no explanation."
This lack of explanation leads others to turn to religion.
"A lot of the medical literature that we're familiar with in the West is written through the lens of Christianity," said Duffin. So many of the doctors who write about sweating blood refer to the description of Christ sweating blood before the crucifixion.
"The religious authors and the medical authors both seem to be citing each other," said Duffin, referring to this as "mutual reinforcement and endorsement."
Yet, religion is non-scientific by definition. Perhaps it is this religious aspect that has caused medicine "to steer away from it," Duffin suggested. Whether they are believers or not, religion is something doctors "want to be respectful of and not treat in a cavalier way," she said. She also noted that cases have been reported around the globe, yet this is the first case study appearing in a North American journal.
Meanwhile, "blood sweat" is extremely rare. Duffin completed her research by consulting older hematologists yet none had ever seen a case for themselves. She said, "it's not there in the books so it's like it doesn't exist, and that raises the question: How do new diseases ever get recognized?"
Overall, the many cases over time convinced Duffin that patients' symptoms were true, unexplained phenomenon. And babies certainly would not be faking it, she said, though when children have unusual, unexplained symptoms, doctors "think the mother is faking it -- doing that to her child."
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"If somebody knows that it's false and how this falseness can be produced, I would be fascinated to learn," she said. There's enough cases in the scientific literature now that it's really hard to believe all these doctors were duped.
"There comes a point where you have to say, 'Hmm this looks like something real.' And now it befalls the rest of us to figure out what it might be," she said. "I am no longer as skeptical as I was."