FAMILY MEDICINE® COLUMN
By John C. Wolf, D.O.
Associate Professor of Family Medicine®
Ohio University College of Osteopathic Medicine

WINTERTIME MALADY: CRACKED NAILS AND SPLIT FINGER TIPS

Question: I've had problems with my fingernails becoming brittle and breaking easily in the winter. I also have trouble with the skin on my fingertips becoming cracked and tender, but I'm not troubled with this in the summer. I've noted that others seem to have the same difficulty, too. Are these problems related, and what can be done to help them?

Answer: In my personal medical library, my books on dermatology take up about a foot of shelf space. Among those books, I have three that deal just with nail problems. My point is that there are many, many problems that can affect the fingernails, toenails and skin, so it's hard to be sure of the cause of any individual's complaint without a thorough history and physical examination. Despite this, I think I can hazard a fairly accurate guess as to the likely source of the problems you describe.

You mentioned the problems with your fingertips and nails as being limited to the wintertime. That makes me believe the underlying cause is the same for both problems, and it probably is a consequence of your age and the dry environment in which you live.

Age is a factor because as we get older, the production of sebum the normal skin oil decreases. Sebum plays a key role in helping the skin retain water. As the amount of sebum production decreases, external factors such as wind and dry air can cause excessive drying that, in turn, leads to cracked, tender fingertips. It is unusual to see this type of skin problem in those in their twenties or younger, while it is a common malady for those of us who are 40 or older.

The two primary sources of skin dryness are low humidity, or the "dry air," which I alluded to earlier, and somewhat paradoxically excessive exposure to water through bathing or swimming.

When the relative humidity is 20 percent or less, the skin can dry out very quickly. This typically occurs in our homes and work places as a result of making them comfortably warm when the outside temperatures are low. Heating the air drops the relative humidity of the indoor air to low "desert dry" levels. This desert-like environment pulls moisture from the skin making it brittle, dry and cracked just like your fingertips.

Those who have a generous amount of sebum have more protection from drying than do those with a lesser amount. Therefore, young individuals usually don't have as much difficulty with dry, cracked skin in the winter.

Why is it, then, that exposure to water particularly hot soapy water can also lead to skin dryness? Obviously, while your hands are in water, the skin is moist. However, once you remove and dry them, you remove some of the protective coating of sebum and, hence, you have an actual net loss of moisture. Soap accelerates this drying process because it facilitates the removal of sebum.

Fingernails are mostly made of keratin, a protein substance that is softened slightly by water and made more brittle in its absence. Hence, your nails tend to break more often in the winter.

Liberal and frequent use of hand lotions will certainly reduce the amount of trouble you experience with dry skin and cracked nails in the winter time. Use of "moisturizing" soaps will reduce the amount of drying soap causes as will washing with tepid instead of hot water. And finally, adding extra moisture to the warm air inside the house by using a humidifier or vaporizer should help your hands stay "summertime soft."

Family Medicine® is a weekly column. To submit questions, write to John C. Wolf, D.O., Ohio University College of Osteopathic Medicine, Grosvenor Hall, Athens, Ohio 45701.