Blonds have more fun. Redheads are harder to numb. No, this is not a nursery rhyme; it’s science.

I perform about 10 biopsies every day. That’s 50 times every week or 2,500 times every year that I numb people up. There are two things I know for sure: 1.) 1% lidocaine with epinephrine works instantly and completely to numb the skin. 2.) There is a tremendous amount of variability in people’s pain threshold.

If you have ever wondered why you feel pain when a doctor or dentist numbs you for a procedure, then take a look in the mirror. Your red hair might be the reason for your pain.

It is not that redheads are wimps or even that redheads are especially sensitive to pain. It is that redheads seem to be resistant to the numbing effects of lidocaine. Anesthesiologists at the University of Louisville in Kentucky did a study to determine pain sensitivity in red-haired women as compared to dark-haired women after their skin was numbed with lidocaine. They tested both topical lidocaine cream and injections of lidocaine. Both groups had the same amount of numbing medication. They then subjected the volunteers to painful stimuli such as mild electroshocks, intense cold, and intense heat.

The results: the redheads were more sensitive to pain as compared to the dark-haired women. What is the cause of this disparity (other than the theory that redheads’ parents are too soft on their kids growing up)? Red hair occurs mostly in people of Northern European descent. It is the result of a mutation in a receptor called the melanocortin-1-receptor (MC1R). As a result, people with red hair make pheomelanin instead of eumelanin. Pheomelanin is reddish or copper as compared to eumelanin which is brown or black.

Although it is not clear, it seems that the MC1R mutation in redheads leads not only to red hair, but also to differences in pain sensitivity in the brain. These differences become apparent when we try to suppress noxious stimuli with local anesthetics as well as with general anesthesia in the operating room. The good news is that although there do seem to be real differences in pain sensitivity, the differences are small, and it is certainly still possible to adequately and completely numb the skin of people with red hair.

“But what about blonds?” you ask. Unfortunately the researchers could not look at blonds in this study. Apparently they all got lost on the way to the experiment.

Photo: Vincent Boiteau (flickr)

I see a lot of tattoos in clinic. They tend to be of three varities: old men with vintage war-time tattoos, young men with authentic NBA-style tattoos, and women who want to know how they can get rid of their tattoos.

It might be that despite there are increasing numbers of women getting tattoos (some reports claim that 65% of people who get tattoos are women), there is also more social pressure for women to remove them.

A study published in the Archives of Dermatology seems to support this. The study interviewed nearly 200 people. They asked people why they got the tattoo and why they wanted them removed. They compared answers from a study done in 1996 to 2006. In 1996, more men requested tattoo removal than women. However, in 2006 most of the tattoo removal request were in women (nearly 70%).

The researchers found that women with tattoos typically were white, single, college educated, and with moderate to strong religious beliefs. According to the study authors, women got tattoos “to be unique” and liked the sense of both both femininity and power it gave them.

However, they found that women were much more likely to report stigma problems as compared to men. They were also more likely to say that they hid the tattoo and that they felt that they no longer wanted it because they “grew up.” Careers were also a significant reason for women to want their tattoos removed. Other reasons why women wanted tattoos removed were embarrassment, problems with clothes, and negative comments.

It is interesting that historically, tattoos were associated with men, but now more than half of people who get tattoos are women. At the same time, women are more likely to experience negative social consequences and be more likely to want their tattoo removed as compared to men.

Tattoos are an ancient body art. They are often beautiful, and the majority of people who have tattoos are satisfied with them. It is unfortunate that there is more negative social consequences to having a tattoo if you are a woman as compared to men. The fact that a tattoo on a women’s lower back is sometimes referred to as a “tramp stamp” is an example of this stigma. As tattoos become more popular for women, perhaps negative societal stereotypes will fade away.

If you do want to remove a tattoo, see a physicain. Creams and balms advertised to remove tattoos do not work.

Can putting bacteria on your skin actually cure disease? Perhaps.

Eczema (which is also called atopic dermatitis) is a common skin condition. People with eczema have itchy, scaly, dry skin. It often develops in infancy and improves as you get older. Some people with severe eczema have the disease for their whole lives. Atopic dermatitis seems to develop in people because they have both an imperfection in their skin’s barrier and because their immune system is a over-active.

A new way of thinking about eczema, as well as many other diseases, is that there is also an imbalance of bacteria living on your skin. Each of us has literally trillions of bacteria living on our skin as well as in our intestines and respiratory tracts. Whereas we traditionally think of infection from bacteria as causing disease, it seems that some diseases might be the result of loosing normal bacteria. This is why many people take probiotics and eat yogurt for gastrointestinal disorders — eating these bacteria-laden foods and supplements replenish normal bacteria — bacteria that is meant to live with us. These species of bacteria that share our bodies are known as normal flora (sounds like were walking flower gardens, doen’t it?).

Now a study from the United Kingdom has found that applying a cream that contains a non-pathogenic bacteria, Vitrescilla filiformis, to patients who have eczema can actually treat their skin condition. The study, published in the British Journal of Dermatology, found that patients treated with cream with a 5% concentration of the bacteria for 30 days had significantly reduced eczema, itching, and sleeplessness (from scratching at night) as compared to patients who applied a placebo cream that did not contain the bacteria.

The authors speculate that using the bacteria laden cream might work because the heavy concentration of “good” bacteria displaces “bad” or pathogenic bacteria such as Staph aureus. It might also be that restoring the normal flora on your skin helps to calm the immune system, decreasing the eczema in these patients. 

In either case, the results of this study are interesting. I think that in the future we will be reading much more about the importance of mantaining a healthy growth of bacteria on your skin. Of course, this does not mean that next time you hurt yourself, you should “rub some dirt on it,” like Peyton Manning recommends. Dirt has lots of not-so-good bacteria in it that is likely to do more harm then good.

Then again, Peyton has a superbowl ring and I don’t, so maybe you should listen to him.

We know that ultraviolet light from the sun causes damage to your skin. That’s because ultraviolet light is a form of radiation. It damages the delicate DNA in your skin cells, leading to aged, damaged skin and to skin cancers. It also causes free radicals to develop in the skin, damaging fragile elastin and destroying collagen, leaving skin wrinkled, lax, and without elasticity. Although most of the damage is done by this high energy form of radiation, new research suggests that even low energy forms of radiation are harmful.

Although most of the energy from the sun is visible and ultraviolet light, about 30% of solar radiation is from infrared light. Infrared light is essentially heat from the sun. It’s what warms you up when you sit in that little spot of sunlight on your sofa in the winter and what makes you sweat when you lie out at the beach in the summer.

A study published in the Journal of Investigative Dermatology (a basic science journal of skin care) found that when researchers exposed volunteers to infrared light in doses similar to what they might get in a couple of hours sun exposure, their skin produced up to a 14 fold increase in collagen chopping enzymes. These enzymes, called matrix metallo-proteinae, are normally produced to break down collagen. Increased levels of MMPs can be seen in autoimmune diseases such as rheumatoid arthritis.

The study also found that health-promoting antioxidants in the skin were depleted following exposure to the infrared light.

Although more research is needed to confirm that infrared light exposure does lead to the type of damage that causes aging, the circumstantial evidence is strong that it does. Unfortunately, sunscreens do not protect against infrared light damage. Even broad spectrum sunscreens that protect against both UVB light (which is about 280 – 320 nm) and UVA (320 – 400), offer no protection for infrared light (760 -1440 nm).

Preventing photoaging (such as wrinkles, sagging, and sun spots) might be more difficult than we had realized. The best way to minimize aging from the sun is to avoid sun exposure during peak hours of 10 AM to 2 PM and to cover up with a hat and long sleeves if you are going to be in the sun all day.

Don’t forget, if you are committed to protecting yourself from sun exposure, then it is a good idea to supplement your diet with vitamin D. By taking 1,000 IU daily, you will keep your vitamin D stores high, and won’t need to worry about using the sun to get your daily vitamin D.

Photo: Greg Donikian

Dermatologists pride themselves on making a diagnosis just by looking. But what if I could diagnose skin cancer with my eyes closed? It might be possible thanks to my friend here.

Inspired by studies of dogs using scent to detect cancers, researchers at the Monell Chemical Senses Center in Philadelphia sought to uncover what scent dogs pick up on that might lead them to find skin cancer. First they used special assays to identify volatile chemicals on the skin that can be detected as smells. They found a hundred distinct compounds that could be potential smells (for those with a much more sensitive sense of smell than ours). They then sampled 11 patients with a common skin cancer, called basal cell carcinoma, and 11 patients without skin cancer. They found that one scent, dimethylsulfone, increased while another, 6-methyl-5-hepten-2-one, decreased in the patients with skin cancer as compared to the controls.

The researchers also found that certain smells were associated with age differences. They attributed some of these age related changes to accumulation of foods and of products used on the skin for years. It has often been said that we are what we eat. Apparently, we can now identify specific smells to prove it. (As I can tell you from the guy on the treadmill next to me in the gym this morning, garlic is one food that is definitely detectable as a skin odor.)

The next step in the research will be to see whether or not different odors can predict if someone has a basal cell carcinoma, even if it has not been discovered clinically. These studies have not been done yet but will likely be done in the near future. Using a hand held smelling device to find a skin cancer sounds a little like Dr. McCoy from Star Trek, but it might just be how we practice medicine in the future. Although I doubt technologies will completely replace physical exams to diagnose disease, they will certainly make physicians much more accurate and efficient.  It might be analogous to the way CT scans or MRIs are used to find cancers by imaging the body.

With skin cancers like basal cell carcinoma, early detection could mean a much less invasive treatment to remove the skin cancer, even avoiding surgery in some cases. If similar scent detection could find deadly melanoma in its early stages, then it might mean curing a patient with simple surgery rather than finding it too late when nothing can be done to treat it.

Photo: Bazusa

My friend just saw a dermatologist back home for an itchy rash on her legs. Her dermatologist prescribed a topical steroid, Verdeso Foam, for her rash.

Verdeso Foam = $256.78

Generic Triamcinolone steroid cream = $9.99

What’s the difference? The generic drug company doesn’t take her dermatologist out for lunch.

Liposuction has gone green (er, yellow actually).

Apparently a Beverly Hills physician who specializes in liposuction decided to prove that action speaks louder than words when it comes to being green. He took the fat that he sucked out of patients and turned it into biofuel to fuel both his and his girlfriend’s cars.

He is not the first person to turn fat into fuel. According to an article in Forbes magazine about the physician, triglycerides from fat can be converted into usable fuel at a ratio of 1 pound of fat to about a gallon of fuel.

He most certainly is the first (last?) person to use human fat to fuel his SUV. On average most liposuction procedures remove 10 pounds of fat or less. Not bad if you drive a Smart car, but he drove a Lincoln Navigator.

The next time you feel lonely, remember this: you always have a few friends with you. No, not your Tweeple, your bacteria.

You have lots of them with you at all times; so many in fact, you’re like a walking planet. There are far more microbes living in and on you then there are people on earth! According to an article in The Economist, there are 100 trillion microbes living with you — 10 times the number of cells you actually have (so technically, you’re 90% bacteria, 10% human).

We are only now starting to comprehend the importance of this relationship with our lowly microbe friends. The disease model used to be simple: If you are infected with bacteria, you are sick. If you are bacteria free, then you are healthy. Not so anymore.

In fact, it is probably more true that losing a few billion of your bacterial friends leads to sickness, rather than to health. A better health model is that it’s not important to be free of bacteria to be healthy; rather it is important to have the right balance of microorganisms living with you to be disease free.

The first place we are likely to see the importance of healthy bacteria in skin disease is in eczema. Eczema, or atopic dermatitis, is a chronic itchy rash that often occurs in childhood and can last for years. It appears that one of the problems in patients with eczema is that they have an overgrowth of unwanted bacteria and a loss of other, good or healthy bacteria. Restoring this bacterial balance might ironically calm the immune system, improving eczema.

Look for new therapies in the upcoming new year such as creams and probiotic pills that don’t kill bacteria, but rather give you good bacteria. Future technologies will likely be able to detect imbalances of bacteria to diagnose disease and to foster health. It’s also another example of how Eastern medicine, with its principles of balance and natural remedies, might have gotten it right all along.

Photo: Tom@HK flickr.com

Are you taking your medications? Probably not.

In a recent dermatology study, a mere 50% of adults and 30% of children were still using their medications 8 weeks after they were prescribed.

But what if I sent you a text to remind you? Would you be more likely to take your meds or use your creams?

Taking medications or applying creams takes effort and discipline. Unless you form a new habit and apply your medication or take your pills at the same time everyday, it is unlikely you will persist. It is similar to exercising — if you exercise at different times and different days, then it is much more difficult to stay exercising than if you developed a habit and did it as part of your daily routine.

There might be a new way to help encourage people to get into a habit of taking their medication everyday: text them.

A recent study presented at a Society for Investigative Dermatology meeting showed that texting patients actually improves compliance (that is, the likelihood that they will take their medication). In the study, 70 cell phone users were randomized to receive a text message reminder to apply sunscreen everyday or to not receive the text reminder.

At the end of 6 weeks those who received the text reminder were more likely to apply their sunscreen as compared to those who did not receive the text. In the text group, people used the sunscreen 56% of the time while in the control group they used it only 30% of the time.

The researchers cleverly attached the weather forecast to the text message to make the message more useful and to encourage people to open the message and read it. The act of opening and reading the message everyday helped them get into the habit of applying the sunscreen everyday, improving their compliance.

In my practice more and more patients use email to communicate with me. Texting might be another way to communicate with patients to help them be more compliant with their therapy.

You can’t text me, but you can twit me if you like.

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Photo: Sintex

Sun spots are a sign of aging; it takes years of sun damage to develop them and they are associated with being old. As such, patients often ask me what they can do to get rid of them.

There are many ways to treat sun spots including freezing them with a cryospray, zapping them with a laser, applying a chemical peel, and treating with bleaching creams. Treating them with lasers, peels, or freezing can be painful and can lead to more pigmentation from damage done by the treatment. Bleaching creams can work, but many of the products currently available are not potent enough to lighten these spots satisfactorily.

A recent study published in the Journal of Drugs and Dermatology examined the effectiveness of a new treatment that combines a bleaching agent with a retinoid to treat these brown spots. Retinoids are used to treat a variety of skin conditions from acne to wrinkles. They are effective antiaging agents and smooth out pigment irregularities. They found that applying Solage® (which contains mequinol, a bleach, and tretinoin, a retinoid) lightened brown spots after two months of use. They also found that the treated spots did not return after stopping the treatment.

Because sun spots are the result of damage from ultraviolet light, it is necessary to wear sunscreen and avoid sun exposure in the treated areas or the brown spots will eventually come back (not to mention, you would develop new ones).

Post written by Jeffrey Benabio, MD. You might also like:

New Powerful Skin Antioxidant From Ferns

Hormone Replacement Therapy Does not Make You Younger

10 Things You Should Know About Laser Hair Removal

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Photo: Sukanto Debnath