More than genetics, hormones, or pollutants, the sun is a lupus patient’s number one enemy. Any amount of unprotected exposure to the lupus sun sensitivity beams will leave a lupus patient with a red, scaly, or even painful rash.
And the sun isn’t the only thing that can incite this kind of reaction. The sun’s mere reflection across a body of water, fluorescent lights, photocopy machines, tanning beds, or any bright source of light can lead to redness and inflammation (1).
Although lupus patients have learned to avoid the sun and wear sunscreen on a daily basis, many people still don’t understand exactly why they are so sensitive to the sun. Sadly, this only limits the treatment of their disease.
In this article, we will explain the different mechanisms involved in photosensitivity and phototoxic reactions. This knowledge is essential in order to comprehend lupus as an illness and ensure the effectiveness of its treatment.
Lupus Sun Sensitivity and Photosensitive Mechanisms
Lupus erythematosus is actually a group of autoimmune disorders, which range from systemic to focalized and from mild to severe or life-threatening (2). Due to a mix of genetic factors and environmental agents, the body’s immune system begins to attack normal cells.
In the systemic form of the disease, white blood cells can attack many different organ systems, included but not limited to the heart, kidneys, brain, articulations, and skin (3). In the cutaneous form of the disease, the symptoms are focused mainly on the skin. Lesions can be superficial and limited to the face and heal completely after only a couple of weeks or be red, scaly, and round, lasting several months and leading to scarring and hair loss (4).
As you can see, lupus has many forms and manifestations. All of these variations have been proven to worsen after exposure to UV radiation (5).
This is due to the fact that lupus naturally produces a state of accelerated skin cell death since white blood cells begin to attack the body’s own healthy tissue, leading to inflammation and skin lesions. UVA and UVB rays only aggravate this situation.
UVB causes cytokine levels to increase as well as many other proinflammatory substances, such as interleukin‐1, interferon, and tumor necrosis factor‐α (6). These substances attract more white blood cells, further stimulating skin cell death and promoting the accumulation of dead or damaged cells within the dermis.
UVA also inhibits the body’s natural antioxidant pathways, thus increasing oxidative stress and systemic inflammation (7). Additionally, UVA has longer wavelengths that can penetrate deeper into the skin and produce direct DNA damage, marking even more healthy cells for apoptosis.
It is important to point out that experiencing a little redness after being out in the sun is a normal reaction and doesn’t constitute as photosensitivity. A confusion surrounding this term has lead many people to being wrongly diagnosed.
Many photo-provocation studies have clearly demonstrated that the onset of true photosensitive reactions is often delayed. One study reported that over half of the reactions occurred longer than 1 week after photo-testing (8). It has also been shown that these reactions last several days or even up to several weeks.
You should also remember that sun sensitivity covers not only skin flare-ups but also systemic symptoms such as fatigue and joint pain (9).
Photoprotection: a way of life
After viewing all of the science behind flare-ups and the phototoxic reactions lupus sun sensitivity patients experience, it is clear to see that photoprotection is the key to achieving a good quality of life.
Sun avoidance must be exercised on a daily basis. Photoprotective clothing, such as shirts will long sleeves, hats, and long hats is a must (10). Also, it is recommended for light-sensitive people to stay indoors during midday when the sun’s radiation is the most intense. This is usually from 11 in the morning to 4 in the afternoon during the summer months (11).
Frequent sunscreen application should also be part of your daily routine. Broad-spectrum sunscreen is highly recommended and should be reapplied after exercise, swimming, or sweating (12).
Topical antioxidants are a powerful tool. Creams that contain retinoids, or vitamin A, have been proven to prevent the effects of oxidative stress and UV-damage (13). Applying topical vitamin E has also been shown to minimize the appearance of redness and inflammation after prolonged UV exposure (14).
Oral supplements have also become very popular in recent years in the treatment of lupus erythematosus. Since UVA radiation stimulates oxidative stress, replenishing your body’s antioxidant reserve is an effective way to combat photosensitivity.
Supplements should include polyphenols, a powerful antioxidant compound, like in capsules of green tea extract, Polypodium leucotomos, or pomegranate extract (15). Vitamin supplements are also very helpful. The most beneficial vitamins for skin health are vitamin A (16), C, D (17), and E.
Lastly, you should make you’re your diet is loaded with food that is rich in antioxidants. Luckily, all brightly colored fruits and vegetables contain carotenoids, which are well-known for their antioxidative properties (18). Some foods to try include bell peppers, tomatoes, carrots, pumpkin, and all dark leafy greens.