The Dermatology Blog

A patient of mine with severe hand dermatitis has an identity problem. She applied for a job that she is well qualified to get, except she doesn’t have any fingerprints. Her job requires a security clearance, and she has to have fingerprints to verify her identity (and to verify that she isn’t wanted in Montana). But her severe hand dermatitis has left her fingertips scarred, and she is unable to give adequate fingerprints.

Why do we have fingerprints in the first place? The ridges are unique and allow you to be distinguished from billions of other people. Although wonderful for the FBI, your fingerprints were never meant to assist in identifying you.

It has been traditionally thought that the tiny ridges increase the coefficient of friction of the skin making it easier to grasp and hold things. A smooth surface makes handling delicate objects like a dime, difficult, especially if your hands are wet.

New research suggests that the grooves have another, possibly more important function: they improve your sense of touch. Fingertips are exquisitely sensitive to touch. This is partly due to a special nerve called the Pacinian corpuscle. The tips of your fingers are packed with these sensitive receptors. One sensation that they are particularly attuned to is vibration. It turns out that the ridges on your fingertips when rubbed against an object create a  fine vibration that is not noticeable to you, but is detected by your Pacinian corpuscles.

Loss of fingerprints is uncommon. It can happen from trauma, as from a burn, or from chronic skin diseases such as eczema, psoriasis, or scleroderma. There are also rare genetic conditions such as dyskeratosis congenital, an inherited condition that leads to scaly skin and increased risk of skin cancers, where patients are born without fingerprints.

Excess inflammation, as from dermatitis or psoriasis, can sometimes lead to temporary changes in the fingerprints. These changes can be resolved with topical steroids or other systemic medications to treat the underlying condition. Once the fingerprint is scarred, however, there is no way to regenerate it.

Post written by Dr. Benabio Copyright The Derm Blog 2009

Photo: D. Sharon Pruitt (flickr)

Argh! You cleaned out your high school locker years ago and now you have acne pimples on your jaw this morning. You’re not alone — 1 in every 5 women over 25 has acne.

Adult acne, in contrast to the teenage type, occurs more often in women. For some women, this is the first time they had acne; we call this late-onset acne. For other women, their acne never stopped from childhood into adulthood; we call this persistent acne. Many of my women patients have other names for adult acne, but they cannot be printed here.

It Must Be Hormones

We like to blame everything on hormones. In the case of acne, hormones contribute, but they are not the only factor. Stopping birth control pills causes a change in hormones and is  a cause for acne in adult women. Similarly, using progestin-only birth control pills affects hormones in such a way as to cause breakouts. Pregnancy is a time of dramatic hormone fluctuations and for some women, dramatic acne. Similarly, menopause can trigger outbreaks. Despite these known hormonal triggers, most women who have acne do not have hormonal imbalances (they are normal fluctuations in hormones). Foods or supplements that claim to balance women’s hormones don’t. So save your time and money, they won’t help your acne.

You Can’t Scrub Acne Away

Exfoliating to open pores can help, but only when done in moderation. Harsh scrubs or repeated microdermabrasion will irritate the skin and make acne worse. Instead, use mild chemical exfoliators such as salicylic acid or glycolic acid which are found in many women’s cosmetics and in acne treatments. Products that contain benzoyl peroxide also help to exfoliate and will treat adult acne.

Don’t Give Up Your Scharffen Berger Chocolate

Although myths of chocolate and pizza causing acne have been disproved, it is true that consuming cow’s milk (which contains hormones) as well as eating a diet high in carbohydrates (which causes inflammation) can contribute to acne. Eating chocolate once and a while, especially good chocolate, will not cause or worsen your acne.

Cosmetics Cause Acne

Many skincare products contain ingredients that clog your pores, triggering acne. Pantene shampoo as well as many hair conditioners have been known to cause this problem. Also, sunscreens are notorious for causing acne. If you notice that your acne is worse around your hairline or that it has flared since you started sunscreens, then try changing your products; it might be all you need to clear up your face.

Photo: Foundphotoslj (flickr)

Post written by Dr. Benabio Copyright The Derm Blog 2009

Right now your hands are teeming with bacteria. Countless trillions of organisms call your skin home, and that’s a good thing. Skin infections do not arise because you have bacteria on your skin. Rather, they arise because the type of bacteria on infected skin is not healthy bacteria but aggressive pathogenic bacteria.

Determining which bacteria are good and which are dangerous is difficult, but our immune systems have managed to get it right most of the time. When our immune systems are wrong, either an infection develops, or excess inflammation develops, as is the case in eczema or psoriasis.

Telling good from bad is hard. There are hundreds of types of bacteria on your hands right now. A recent study of college students (perhaps not the cleanest group of individuals) discovered that the average student has 140 different types of bacteria on his or her skin. There were over 4,000 different types of bacteria identified across all the students. Not surprisingly, the most common types were familiar household names: Propionobacterium (the bacteria responsible for acne), strep, and staph (of which the infamous methicillin resistant staph aureus, MRSA is a subtype).

There were also differences in the bacteria on the dominate hand versus the non-dominant hand — namely bacteria normally found in the gastrointestinal track was found more often on the dominant hand. This will no doubt lead to a follow up study of: “Do college students wash their hands before leaving the bathroom?” (Research so far does not look promising).

Photo: Pink Sherbert Photography (flickr)

A bruise is blood that has leaked into your skin. The blood is red, but it appears blue when seen though the skin layers. Bruises can be frustrating, especially for women who always get them on their legs the day they wear their new INC empire-waist jersey dresses.

Bruises are a normal response to injury. Who among us has not walked into the corner of the bed or miscalculated the exact location of the coffee table when crossing the room? Most of the time bruising does not indicate any underlying diseases, except for clumsiness.

Women bruise more easily than men, especially on their thighs, calves and buttocks. This easy bruising is because women have exposed blood vessels and thinner skin as compared to men, so even unnoticed injuries to their legs leave noticeable bruises.

Usually bruising is a minor, lifelong problem. However, if bruising develops rapidly or is getting progressively worse, then investigation is needed. Also, bruising that is associated with taking medications like aspirin, plavix or coumadin should be discussed with a physician. Bruises that appear on the face, back, or abdomen are not typical and should also be evaluated by a physician. Also, if bruising is accompanied by bleeding such as heavy periods, recurrent nose bleeds, bleeding from the gums, or blood in your urine or stool, then you should see a doctor.

There is little you can do to prevent bruises. When bruising is the result of taking certain medications such as ibuprofen, fish oil or ginkgo, then stopping these can lessen bruising. Also, wearing long sleeves and long pants can be the difference in whether a bruise develops or not after a minor injury.

After an injury, try to minimize the amount of blood that leaks out to minimize the bruise. Sit down and apply pressure to the injured spot for 10-15 minutes. You can also use ice, but only for 15-20 minutes (longer than 20 minutes can cause worsening of the bruise). Apply ice with a wash cloth or other layer between it and your skin. Avoid hot showers or hot baths for 24 hours after the injury as the heat can restart bleeding into the skin.

Vitamin K and bromelain (found in pineapples) might be helpful in resolving bruises more quickly. Look for them in topical products or in oral supplements that can be taken for a few days after a bruise develops. And look out for the coffee table.

Post written by Dr. Jeffrey Benabio, Copyright The Derm Blog 2009.

Photo: Christy Gordon (flickr)

So how does a dermatologist like me protect against skin cancer? I go to Peet’s Coffee.

There are plenty of reasons to enjoy a cappuccino in the morning (if you can still afford it), and preventing skin cancer might be one of them.

Studies of mice have shown that feeding them caffeine protects them against ultraviolet radiation, which is similar to sun exposure for humans. The protection is most effective when the mice exercise. (So the researchers basically make them drink espresso then hit the exercise wheel.)

While epidemiologic studies and animal studies are helpful, it is nice to have a scientific explanation to support the claim. New studies show how it works.

Researchers exposed skin cells that were growing in culture to caffeine (possibly when one of the graduate students spilled his Red Bull on the petri dish). They then exposed the cells to damaging UVB light. They found that the caffeine-treated, UV-damaged cells underwent programmed cell death. When cells are damaged, but don’t die, they grow into cancerous tumors. When damaged cells die, they are no longer a threat to the body and are safely eliminated.

As sunscreens become more sophisticated, ingredients like caffeine will be added to soak up the damaging oxidants or to protect the skin from developing cancer. Botanicals like ferulic acid, derived from ferns, have proven themselves as powerful additives to sunscreens and are the future of sun protection.

Although there is not enough evidence to advise patients to drink more coffee as a means of sun protection, do you really need another reason to have a nice macchiato in the afternoon?

Photo: Burnt Phrases (flickr)