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)

What are cold sores?

Cold sores are a herpes virus infection. Yup, that’s the same as genital herpes, but usually a different strain of virus. Type 1 herpes prefers the mouth, and presents as a group of blisters on the lips — a cold sore or fever blister. Type 2 herpes usually infects the genitals and surrounding area. The viruses are particular about where they infect but not exclusive — it’s possible to get a type 2 herpes virus infection on your lips or to get a type 1 virus infection on your genitalia.

The initial infection is generally the worst; in oral herpes, fast developing, painful blisters form on your lips and in your mouth within a week of being infected. The blisters crust over and form scabs which take a week or so to heal.

Once the virus infects you, it is yours for life. It will live dormant in the nerves of your lips and face. In some people a second outbreak never occurs. However, in most people, the virus reactivates on seemingly random occasions, leading to an uncomfortable and unsightly outbreak.

Outbreaks start as a red, swollen spot on your lips. The patch of skin usually feels numb or burns for a few hours before any changes appear on your skin. Then fluid filled blisters develop, which break within hours, leaving a crusted scab for days.

How is herpes simplex diagnosed?

Seeing the outbreak is usually enough to diagnose a herpes virus infection, but it can be confirmed by a blood test, a culture, or a direct florescent antibody (DFA) test.

How do you get a cold sore?

It’s a virus, so you catch it like any other virus – from someone else with a herpes infection. It’s highly contagious though, and most people get it in childhood from close contact with an infected family member.

You can get cold sores by kissing someone who is infected. Though the virus is more contagious when you have an outbreak, it is possible to infect people (or to get an infection) even when there is no visible outbreak.

Outbreaks are triggered by many things including sun exposure, stress, fevers, illness, certain medications, injuries, laser treatment, chemical peels, fillers, and even Botox.

How do you treat cold sores?

The initial infection is the most important to treat. It is the most severe and usually involves the inside of your mouth (recurrent outbreaks are usually on a limited area on the outer lips).

Herpes can be treated with topical antivirals such as Abreva (available over the counter) and by oral antivirals such as acyclovir (Zovirax) or valcyclovir (Valtrex). Unfortunately both the topical and oral antivirals do not cure cold sores; rather, they shorten the the course by a few hours to a day or so. It’s important to start treatment at the first sensation of an outbreak, before there are any visible changes on your skin.

How do you avoid cold sores?

• No kissing. OK, so maybe that is not an option. In truth, try not to worry about it. The virus is very common and highly contagious. Certainly if you have an active outbreak you shouldn’t touch it or kiss anyone until it has healed completely. You may be the world’s greatest kisser, but you’re not so irresistible that someone can’t wait a week for that fever blister to heal.
• Once you have been infected, there are ways to minimize outbreaks. Because cold sores can be trigged by ultraviolet light and chapped lips, apply a lip balm with a 30 SPF sunscreen, especially before heading out to the beach or snow skiing in the winter.
• Lip licking can lead to irritated lips and to an outbreak of oral herpes. Apply a protective ointment like Vaseline and try to break yourself of the habit.
• Some people have such frequent outbreaks that they need to take an oral antiviral medication, such as acyclovir. This has been shown to decrease the occurrence of oral herpes, but at the expense of having to take a pill everyday.
• Although usually a self-limited condition, herpes can cause a severe, widespread infection in rare instances. This occurs when the skin surrounding the outbreak is disrupted as happens in people with eczema (atopic dermatitis), or following a facial laser resurfacing or chemical peel. This is why patients take an oral antiviral medication before having facial resurfacing to prevent such an outbreak.

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

Skincare myths: Cuts heal better when you let air at them

How to Stop a Shaving Nick From Bleeding

Are You Over-Scrubbing Your Face?

How to grow a beard

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