Summer is here or at least almost here depending on the part of the country you live in and it is the best time of the year! It is the season of endless cookouts, pool parties, picnics in the park, outdoor sports, and beach vacations. I love summer and I love going to the beach. However my trips to the sun are not the same as they used to be. I try to avoid too much sun exposure because I, like most other Lupus patients, have been told to avoid the sun. We have been told that Lupus is a photosensitive disease. Only about one out of three lupus patients is sun-sensitive. If you don’t know if you are, or are not, sun-sensitive, it’s OK to try a little (early morning, late afternoon) exposure for a few minutes. If you don’t have any symptoms in a few days, increase a little bit, and continue until you know that you can tolerate full sun exposure.
What does photosensitivity mean you ask? The current theory, based on experimental evidence, is that UV light causes skin cells to express particular protein molecules (“antigens”) on their surface. These antigens, including “Ro” and “La” (named after the first two letters of the patients in which they were discovered) on the surface of the skin cells react with antibodies (“anti-Ro” and “anti-La”), which latch onto them. These antibodies then attract white blood cells to the skin, which attack the skin cells, leading to the rash. Recently it has been observed that certain skin cells in lupus patients switch themselves off (“apoptosis”) more readily than they should. Another recent study found too much nitric oxide may be made in the skin of lupus patients after sun exposure, which may lead to redness and inflammation. It is unknown why any of these mechanisms are more active in patients with lupus.
Patients who are sun-sensitive show that sensitivity in several ways. Most commonly rash appears, or gets worse. Sometimes, however, they develop joint pains, fever and other signs of general flare-up. Sun-sensitivity symptoms can show up several days or even a few weeks after heavy sun exposure.
So how can you protect yourself from UV light? Sun-avoidance and appropriate sunscreens may reduce the need for treatment with topical steroids or systemic therapy with tablets. Dermatologists have suggested sun avoidance from 11am to 3pm, March to September for photosensitive lupus patients. It’s always safest to avoid very strong sun (beaches, sailing, golf courses), and to use the strongest available sunscreens. Topical sunscreens form the next major component of photo-protection. Sunscreens are either organic chemicals which absorb UV light or inorganic pigments such as titanium dioxide which absorb and scatter UV light. The sun protection factor (SPF) is proportional to the light sensitivity without sunscreen divided by light sensitivity with sunscreen, but it only applies to UVB protection. There is no universal method of labeling sunscreens for protection against UVA. Use of broad-spectrum sunscreens (covering UVA and UVB) should therefore be used and prescribed if necessary.
A study that was published in February found that we tend to apply less sunscreen than is needed to achieve the manufacturer’s recommended SPF.
The most frequently missed areas are the back and sides of the neck, the temples and the ears, which also tend to be the areas where photosensitive lupus patients frequently experience problems.
Because car windows and clouds only protect against UVB, not UVA, photo-protection should not be limited just to sunny days in order to minimize UVA exposure. UV-blocking films may be applied to car and house windows.
Sources of UV light other than sunlight can also cause skin problems in lupus. Photosensitivity in lupus has been reported with fluorescent tube lights, which mainly emit UVB, and photocopiers, which emit mainly UVA. Also using broad-rimmed hats and wearing long sleeves and trousers are all simple and effective methods of photo-protection.