As a dermatologist, treating my patients’ skin, hair and nail issues is my top priority, but educating them comes in a close second. I keep a running list of questions I receive and advice I give that fall outside of the “basics,” so I’ll be sharing these in the coming weeks.
Here, then, are three rules you need to live by to protect your skin:
Rule No. 1: Don’t use old doxycycline or tetracycline. We know you are not supposed to use expired medications; however, we often keep them in our cabinets anyway. Drug manufacturers are required by law to place expiration dates on prescription products, and this date represents the final day the manufacturer guarantees the full potency and safety of a medication.
There are two main issues with expired drugs. First, the expired drugs might not work and second, expired drugs can be dangerous. Doxycycline and tetracycline (brand names include Oracea, Soladyne and Minocin) are often prescribed by dermatologists to treat acne or rosacea. Expired doxycycline and tetracycline fall into the dangerous category because they can cause kidney disease such as Fanconi’s syndrome. For this reason, be sure to toss old doxycycline or tetracycline antibiotics after their expiration date.
Rule No. 2: Use an SPF of at least 15 every day. Many people know to wear SPF when doing prolonged outdoors sports such as golf and tennis. However, small increments of unprotected daily sun exposure add up and cause skin aging, unwanted pigmentation and skin cancer. One study in the February 2004 Dermatology Therapy journal, “An analysis of cumulative lifetime solar ultraviolet radiation exposure and the benefits of daily sun protection,” showed that wearing a SPF of 4 to 10 every day can reduce the accumulated lifetime UV exposure by 50 percent or more. In other words, when you are in your 70s, you will have roughly half the sun damage compared to those who do not wear and SPF of at least 4 every day.
Most people only apply 25 percent of sunscreen necessary to achieve the SPF on the label. (Half a teaspoon is the correct amount.) For this reason, we recommend a SPF of 15 every day to make up for the fact that most people do not apply enough and do not reapply throughout the day. And it goes without saying, prolonged sun exposure (more than 15 minutes of direct sun) requires a waterproof sunscreen of SPF 60 or higher—and don’t forget to reapply every hour.
Rule No. 3: Avoid combination sunscreen/bug repellent products. Several studies have looked at the efficacy of SPF and insect repellent when used together. It has been found that sunscreen loses efficacy when used with the insect repellent N,N-Diethyl-meta-toluamide (DEET). An August 2000 JAAD study, “The effect of sunscreen on the efficacy of insect repellent: A clinical trial,” it was shown that sunscreen does not affect the efficacy of insect repellent. However, when these products are combined, you need to reapply sunscreen more often (but you should not have to increase the amount of insect repellent that you use).
Do you have a skincare question that you’d like me to answer? Post it on our Facebook page and we just might include it in an upcoming story about other skincare rules you should be following!
Dr. Leslie Baumann is a board-certified dermatologist, New York Times best-selling author and CEO of Baumann Cosmetic & Research Institute in Miami.