Photosensitivity, or abnormal sensitivity to light, is one of the most common symptoms of lupus along with fatigue and pain. It was first described as a symptom of lupus in 1851.
Between 50 and 80 percent of people with lupus experience some form of photosensitivity. Its rash most often appears on areas of the skin that have been exposed to ultraviolet (UV) light but may erupt anywhere on the body. The UV light is found in sunlight and fluorescent lights. In addition to rashes, photosensitivity can also cause joint pain, fatigue, weakness, headache, and fever.1-3
Many people with photosensitivity report that exposure to UV light triggers flares.
What does photosensitivity look like?
People who have not yet been diagnosed with lupus often mistake the red, raised rash for a bad sunburn. About half of people with lupus get what is called a butterfly, or malar, rash across the cheeks and nose, sometimes after sun exposure and other times spontaneously. Other types of skin issues triggered by photosensitivity include discoid lesions, stinging, itching, atopic dermatitis, rosacea, scaling, and polymorphous light eruption, short-term skin eruption.
One study found rashes that cropped up within minutes to the next day after sun exposure tended to go away the same day to within a week. Rashes that appeared later after sun exposure, say within a week, tended to last weeks to months.4
What causes photosensitivity?
Normally, skin cells that are damaged by something like too much light die in a process called apoptosis, or programmed cell death. Researchers believe that in people with lupus, apoptosis occurs more often than it should, leading to inflammation of the skin, joints, and other tissues.
One small study found that people who experienced systemic (whole-body) reactions to the sun tended to have more active lupus.4
Another study at the University of Michigan compared the skin cells of people with lupus to cells from healthy skin and found that the keratin-producing cells that make up the top layer of skin produced more interferon kappa (IFN-κ), meaning the skin cells overreacted to UV light and died.5
There does not seem to be a connection between race or ethnicity and photosensitivity.
How is photosensitivity treated?
Avoidance helps to prevent the reactions common to people who are sensitive to ultraviolet (both UVA and UVB) radiation. Tips for reducing UV exposure include:
- Apply sunscreen SPF 70 or higher daily, even on parts of the body covered with clothing. Reapply frequently when outdoors.
- Wear protective clothing such as long-sleeved shirts, wide-brimmed hats, and long pants when outside. You can also find clothing with additional sunscreen in the fabric.
- Avoid going outside when sunlight is the strongest, between 10 a.m. and 4 p.m.
- Avoid working under fluorescent lights indoors.
The kind of medicine used to treat the skin issues caused by photosensitivity vary according to the type and severity of the rash or lesions and include:
- Steroid creams, ointments, gels, lotions, sprays and foams
- Calcineurin inhibitors such as Tacrolimus (Protopic®) or pimecrolimus (Elidel®)
- A short-term course of steroids
- Retinoids
- Prescription Vitamin A
- Diaminodiphenylsulfone (Dapsone®)
- Sulfones
- Gold
- Thalidomide
- Methotrexate
- Azathioprine (Imuran®)
- Mycophenolate mofetil (CellCept®)
- Biologics
- Efalizumab (Raptiva®)
Taking your antimalarials as prescribed can help keep your lupus flares under control and thus may reduce your photosensitivity.