10 Facts About Rosacea

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Rosacea, a skin condition characterized by redness and swelling, is incredibly common: A recent study found that an estimated 300 million people worldwide suffer from it. Here’s what you need to know about the condition.

1. IT HAS A LONG HISTORY.

According to the National Rosacea Society (NRS), rosacea was first described in the 14th century by a French surgeon named Dr. Guy de Chauliac; he called it goutterose (“pink drop” in French) or couperose and noted that it was characterized by “red lesions in the face, particularly on the nose and cheeks.”

2. SCIENTISTS AREN’T SURE WHAT CAUSES IT ...

But they have some theories. According to the NRS, “most experts believe it is a vascular disorder that seems to be related to flushing.” Scientists also think that because rosacea seems to run in families, it might be genetic. Other things—like mites that live on the skin, an intestinal bug called H pylori (common in those who have rosacea), and a reaction to a bacterium called bacillus oleronius—could also play a role in causing the condition. One 2015 study suggested an increased risk among smokers.

3. … BUT SOME PEOPLE ARE MORE LIKELY TO HAVE IT THAN OTHERS.

Though people of all ages and skin tones can get rosacea, fair skinned people between the ages of 30 and 50 with Celtic and Scandinavian ancestry and a family history of rosacea are more likely to develop the condition. Women are more likely to have rosacea than men, though their symptoms tend to be less severe than men’s. But men are more likely to suffer from a rare rosacea side effect known as rhinophyma, which causes the skin of the nose to thicken and become bulbous. It’s commonly—and mistakenly—associated with heavy drinking, but what exactly causes rhinophyma is unclear. According to the NRS, “The swelling that often follows a flushing reaction may, over time, lead to the growth of excess tissue (fibroplasia) around the nose as plasma proteins accumulate when the damaged lymphatic system fails to clear them. Leakage of a substance called blood coagulation factor XIII is also believed to be a potential cause of excess tissue.” Thankfully, those who have rhinophyma have options available for treatment, including surgery and laser therapy.

4. THERE ARE FOUR SUBTYPES.

According to the American Academy of Dermatology (AAD), rosacea “often begins with a tendency to blush or flush more easily than other people.” All rosacea involves redness of some kind (typically on the nose, cheeks, chin, and forehead), but other symptoms allow the condition to be divided into four subtypes: Erythematotelangiectatic rosacea is characterized by persistent redness and sometimes visible blood vessels; Papulopustular rosacea involves swelling and “acne-like breakouts”; Phymatous rosacea is characterized by thick and bumpy skin; and Ocular rosacea involves red eyes (that sometimes burn and itch, or feel like they have sand in them [PDF]), swollen eyelids, and stye-like growths.

5. IT’S NOT THE SAME AS ACNE.

Though rosacea was once considered a form of acne—"acne rosacea" first appeared in medical literature in 1814—today doctors know it’s a different condition altogether. Though there are similarities (like acne, some forms of rosacea are characterized by small, pus-filled bumps) there are key differences: Acne involves blackheads, typically occurs in the teen years, and can appear all over the body; rosacea is a chronic condition that occurs mainly on the face and the chest and typically shows up later in life.

6. YOU CAN FIND IT IN CLASSIC ART AND LITERATURE.

Both Chaucer and Shakespeare likely made references to rosacea. Domenico Ghirlandaio’s 1490 painting An Old Man and His Grandson seems to depict rhinophyma, and some believe that Rembrandt’s 1659 self-portrait shows that the artist had rosacea and rhinophyma.

7. IT MAY BE TRIGGERED BY CERTAIN FOODS AND ACTIVITIES.

According to the National Institutes of Health (NIH) [PDF], people report that everything from the weather to what you eat can cause rosacea to flare up: Heat, cold, sunlight, and wind, strenuous exercise, spicy food, alcohol consumption, menopause, stress, and use of steroids on the skin are all triggers.

8. THERE ARE A NUMBER OF MYTHS ABOUT ROSACEA.

No, it’s not caused by caffeine and coffee (flare ups, if they occur, are due to the heat of your coffee) or by heavy drinking (though alcohol does exacerbate the condition). Rosacea isn’t caused by poor hygiene, and it’s not contagious.

9. THERE ARE SOME PRETTY FAMOUS PEOPLE WITH ROSACEA.

Sophia Bush, Cynthia Nixon, Kristin Chenoweth, Bill Clinton, and Sam Smith all have rosacea. Diana, Princess of Wales had it, too. W.C. Fields had rosacea and rhinophyma, and Andy Warhol may also have suffered from those conditions.

10. IT CAN’T BE CURED—BUT IT CAN BE TREATED.

The NRS reports that “nearly 90 percent of rosacea patients [surveyed by NRS] said this condition had lowered their self-confidence and self-esteem, and 41 percent reported it had caused them to avoid public contact or cancel social engagements.” Dr. Uwe Gieler, a professor of dermatology at the Justus-Liebig-University in Giessen, Germany, and one of the authors of the report Rosacea: Beyond the Visible, said in a press release that "People with rosacea are often judged on their appearance, which impacts them greatly in daily life. If their rosacea is severe, the symptoms are likely to be more significant also, from itching and burning to a permanently red central facial area. However, even people with less severe rosacea report a significant impact on quality of life."

Which makes it all the more unfortunate that there’s not a cure for the condition. Thankfully, though, there are treatments available.

There are no tests that will diagnose rosacea; that’s up to your doctor, who will examine your medical history and go over your symptoms. Doctors advise that those with rosacea pay attention to what triggers flare-ups, which will help them figure out how to treat the condition. Antibiotics might be prescribed; laser therapy might be used. Anyone with rosacea should always wear sunscreen [PDF] and treat their skin very, very gently—don't scrub or exfoliate it. The AAD recommends moisturizing daily and avoiding products that contain things like urea, alcohol, and glycolic and lactic acids.

7 Facts About Blood

Moussa81/iStock via Getty Images
Moussa81/iStock via Getty Images

Everyone knows that when you get cut, you bleed—a result of the constant movement of blood through our bodies. But do you know all of the functions the circulatory system actually performs? Here are some surprising facts about human blood—and a few cringe-worthy theories that preceded the modern scientific understanding of this vital fluid.

1. Doctors still use bloodletting and leeches to treat diseases.

Ancient peoples knew the circulatory system was important to overall health. That may be one reason for bloodletting, the practice of cutting people to “cure” everything from cancer to infections to mental illness. For the better part of two millennia, it persisted as one of the most common medical procedures.

Hippocrates believed that illness was caused by an imbalance of four “humors”—blood, phlegm, black bile, and yellow bile. For centuries, doctors believed balance could be restored by removing excess blood, often by bloodletting or leeches. It didn’t always go so well. George Washington, for example, died soon after his physician treated a sore throat with bloodletting and a series of other agonizing procedures.

By the mid-19th century, bloodletting was on its way out, but it hasn’t completely disappeared. Bloodletting is an effective treatment for some rare conditions like hemochromatosis, a hereditary condition causing your body to absorb too much iron.

Leeches have also made a comeback in medicine. We now know that leech saliva contains substances with anti-inflammatory, antibiotic, and anesthetic properties. It also contains hirudin, an enzyme that prevents clotting. It lets more oxygenated blood into the wound, reducing swelling and helping to rebuild tiny blood vessels so that it can heal faster. That’s why leeches are still sometimes used in treating certain circulatory diseases, arthritis, and skin grafting, and helps reattach fingers and toes. (Contrary to popular belief, even the blood-sucking variety of leech is not all that interested in human blood.)

2. Scientists didn't understand how blood circulation worked until the 17th century.

William Harvey, an English physician, is generally credited with discovering and demonstrating the mechanics of circulation, though his work developed out of the cumulative body of research on the subject over centuries.

The prevailing theory in Harvey’s time was that the lungs, not the heart, moved blood through the body. In part by dissecting living animals and studying their still-beating hearts, Harvey was able to describe how the heart pumped blood through the body and how blood returned to the heart. He also showed how valves in veins helped control the flow of blood through the body. Harvey was ridiculed by many of his contemporaries, but his theories were ultimately vindicated.

3. Blood types were discovered in the early 20th century.

Austrian physician Karl Landsteiner discovered different blood groups in 1901, after he noticed that blood mixed from people with different types would clot. His subsequent research classified types A, B and O. (Later research identified an additional type, AB). Blood types are differentiated by the kinds of antigens—molecules that provoke an immune system reaction—that attach to red blood cells.

People with Type A blood have only A antigens attached to their red cells but have B antigens in their plasma. In those with Type B blood, the location of the antigens is reversed. Type O blood has neither A nor B antigens on red cells, but both are present in the plasma. And finally, Type AB has both A and B antigens on red cells but neither in plasma. But wait, there’s more! When a third antigen, called the Rh factor, is present, the blood type is classified as positive. When Rh factor is absent, the blood type is negative.

Scientists still don’t understand why humans have different blood types, but knowing yours is important: Some people have life-threatening reactions if they receive a blood type during a transfusion that doesn’t “mix” with their own. Before researchers developed reliable ways to detect blood types, that tended to turn out badly for people receiving an incompatible human (or animal!) blood transfusion.

4. Blood makes up about 8 percent of our total body weight.

Adult bodies contain about 5 liters (5.3 quarts) of blood. An exception is pregnant women, whose bodies can produce about 50 percent more blood to nourish a fetus.)

Plasma, the liquid portion of blood, accounts for about 3 liters. It carries red and white blood cells and platelets, which deliver oxygen to our cells, fight disease, and repair damaged vessels. These cells are joined by electrolytes, antibodies, vitamins, proteins, and other nutrients required to maintain all the other cells in the body.

5. A healthy red blood cell lasts for roughly 120 days.

Red blood cells contain an important protein called hemoglobin that delivers oxygen to all the other cells in our bodies. It also carries carbon dioxide from those cells back to the lungs.

Red blood cells are produced in bone marrow, but not everyone produces healthy ones. People with sickle cell anemia, a hereditary condition, develop malformed red blood cells that get stuck in blood vessels. These blood cells last about 10 to 20 days, which leads to a chronic shortage of red blood cells, often causing to pain, infection, and organ damage.

6. Blood might play a role in treating Alzheimer's disease.

In 2014, research led by Stanford University scientists found that injecting the plasma of young mice into older mice improved memory and learning. Their findings follow years of experiments in which scientists surgically joined the circulatory systems of old and young mice to test whether young blood could reverse signs of aging. Those results showed rejuvenating effects of a particular blood protein on the organs of older mice.

The Stanford team’s findings that young blood had positive effects on mouse memory and learning sparked intense interest in whether it could eventually lead to new treatments for Alzheimer’s disease and other age-related conditions.

7. The sight of blood can make people faint.

For 3 to 4 percent of people, squeamishness associated with blood, injury, or invasive medical procedures like injections rises to the level of a true phobia called blood injury injection phobia (BII). And most sufferers share a common reaction: fainting.

Most phobias cause an increase in heart rate and blood pressure, and often muscle tension, shakes, and sweating: part of the body’s sympathetic nervous system’s “fight or flight” response. But sufferers of BII experience an added symptom. After initially increasing, their blood pressure and heart rate will abruptly drop.

This reaction is caused by the vagus nerve, which works to keep a steady heart rate, among other things. But the vagus nerve sometimes overdoes it, pushing blood pressure and heart rate too low. (You may have experienced this phenomenon if you’ve ever felt faint while hungry, dehydrated, startled, or standing up too fast.) For people with BII, the vasovagal response can happen at the mere sight or suggestion of blood, needles, or bodily injury, making even a routine medical or dental checkup cause for dread and embarrassment.

9 Surprising Facts About the Scientific Study of Sex

vadimguzhva/iStock via Getty Images
vadimguzhva/iStock via Getty Images

The scientific study of sex is much more exciting than an awkward sex ed class. While writing my book Sex Weird-o-Pedia, these were some of the most interesting facts about science and sex that I came across.

1. Some sex researchers didn't want their findings to get into the wrong hands.

The pioneering sex researcher Richard von Krafft-Ebing didn’t want his knowledge in the hands of ordinary folk. So he wrote Psychopathia Sexualis, the founding document of modern sexology—which was published in Germany in 1886 then translated and published in English in 1939—in Latin to discourage regular Joes (and/or Janes) from reading it.

2. You burn more calories mowing the lawn than you do having sex.

Young woman poses for selfie while mowing the lawn
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Sex might seem strenuous when things get hot and heavy, but it's usually not that great of a workout. You'd have to go at it for nearly 200 minutes to burn as much energy having sex as you do during a 30-minute run. Even mowing the lawn burns about three times more calories than sex. According to the British Heart Foundation, sex burns about the same amount of energy per minute as ironing clothes.

3. A surprising number of mothers claim to be virgins.

In a 2013 study of several thousand pregnant women in the U.S. published by BMJ, about 1 percent of the participants claimed they were virgins when they gave birth. This, of course, calls into question the veracity of studies that rely on self-reported sexual behaviors.

4. Penicillin may have ignited the sexual revolution.

One economist says that penicillin, and not the birth control pill, was the real enabler of the sexual revolution. A study published in the Archives of Sexual Behavior in 2013 shows that penicillin contributed to a 75 percent decline in the number of deaths caused by syphilis from 1947 to 1957. Since the new treatment made sex safer, people started having riskier sex, which resulted in increases in the numbers of children born out of wedlock and teenage pregnancies.

5. Twins can have different dads.

A photo of fraternal twins
Aleksandr Zhurilo/iStock via Getty Images

While it is very rare, it is possible for fraternal twins to have two different fathers. What’s more common is for a rom-com to be based on this scenario.

6. Gender may influence how people handle sexual jealousy.

Research from evolutionary psychologists indicates that people’s gender influences how they react to sexual jealousy. For men, they react more strongly to sexual unfaithfulness than emotional infidelity. For women, it is the reverse. The theory behind these behaviors comes back to evolution: Males who were intolerant toward their wives becoming sexually active with other men were less likely to become an object of derision and more likely to see their own genes pass onto future generations. Women who prevented their husbands from emotionally bonding with other women reduced the chances of the men spending their resources on other women.

7. One of Ivan Pavlov's colleagues created his own (slightly x-rated) conditioning experiment with dogs.

You’re probably aware of Russian researcher Ivan Pavlov and his famous conditioning experiment in which he trained a dog to salivate at the sound of a bell. What you might not know is that one of Pavlov’s American students, W. Horsley Gantt, conditioned dogs to become sexually aroused when they heard specific tones. The experiment, according to Mandy Merck's In Your Face: 9 Sexual Studies, was intended "to study conflicts of the drives between ... experimentally induced anxiety states and sexual excitement."

8. Couples whose first child is a girl are more likely to get divorced.

Parents pay attention to their phones instead of their daughter
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Married couples whose first child is a girl are more likely to get divorced than those whose first child is a boy. Scientists are split as to why this is. One theory is that female embryos are better able to endure maternal stress than male embryos, so pregnant women in unhappy marriages are less likely to have a miscarriage if the child they are bearing is a girl. But once they have a daughter, these couples are more likely to split up since there were already fissures in their relationship prior to the child’s birth.

9. There's a link between pubic hair and STIs.

A downside of pubic grooming is that it might raise STI risk. In a study conducted by a University of Texas scholar, people who regularly shaved their pubic areas contracted STIs about 80 percent more often than those who never shaved down there. One suggestion is that those who regularly shave are more likely to tear their skin, making it easier for viruses to enter the body.

Ross Benes is the author of Sex Weird-o-Pedia: The Ultimate Book of Shocking, Scandalous, and Incredibly Bizarre Sex Facts.

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