https://resources.lupus.org/entry/what-you-dont-know-about-sunscreen-but-should

What you don’t know about sunscreen, but should

Lupus Foundation of America

Resource Content

  • Although the Food and Drug Administration (FDA) advises the general public to choose a sunscreen with at least 15 SPF, people with lupus should use sunscreens with at least 30 SPF, as lupus causes increased sensitivity to UV (photosensitivity).
  • SPF stands for “sun protection factor.” SPF measures how much of the sun’s damaging ultraviolet (UV) radiation is required to produce sunburn on sunscreen-protected skin, relative to the amount of UV required to produce sunburn on unprotected skin.
  • The higher the SPF number, the more protection your skin will have (50 is the highest SPF value the FDA is able to test currently).
  • The SPF number does not equal the number of hours of UV protection.
  • A sunscreen labeled “broad spectrum” is the best kind to select as these products protect against both types of damaging UV—UVA and UVB.
  • FDA-approved sunscreen products are available in lotions, creams, gels, oils, butters, pastes, rub-on sticks, and sprays. Note: Products such as wipes, towelettes, powders, body washes, and shampoos may not have received FDA-approval as sunscreens.
  • Protect your lips with a wax-based lip balm of 15 SPF, or higher.
30 SPF Minimum sun protection factor recommended for people with lupus
  • Sunscreens require at least 20 minutes on your skin before they’re activated (less if they contain UV-blocking agents such as zinc and titanium), so don’t wait until you’re outside to apply!
  • A minimum of one ounce of sunscreen—equivalent to two tablespoons—is needed to adequately cover an average-sized adult. That’s the amount that would fit in the palm of an adult’s hand. Experts recommend that people with lupus use twice that amount.
20 Min Sunscreens require at least 20 minutes on your skin before they are activated
  • Take special care to apply sunscreen to your nose, front and back of ears and neck, backs of hands, along your hairline, where hair is balding or thinning, and all parts of your feet that will be exposed to the sun. These high-risk areas for melanoma and skin cancer need extra attention since some of the medications used to treat lupus increase the risk of skin cancer, and people with lupus can be more sensitive to UV rays.
  • Sunscreen should be reapplied at least every two hours while you’re outside, and more often if you’ve been sweating, swimming, or rubbing your skin with a towel.
  • The FDA no longer permits products to claim to be “waterproof” or to offer “all-day protection.” However, products may be labeled “water resistant” for 40 or 80 minutes—meaning how much time you can expect to get the labeled SPF-level of protection while swimming or sweating.
  • Because chlorinated water can inactivate sunscreen, reapply sunscreen as soon as you leave the pool if you’re staying outdoors.
  • Sunscreen containers can be affected by UV as well—wrap container in a towel and keep in the shade or place in a cooler.
  • Sunscreens may or may not have an expiration date. If there’s no expiration date, discard any product that you’ve had for more than three years.