Skin conditions associated with lupus are fairly significant and a major marker of the disease. Of the eleven criteria set by the American College of Rheumatology for a diagnosis of lupus, four are skin-related. These include:
It is important to distinguish cutaneous lupus from systemic lupus erythematosus (SLE). Cutaneous lupus refers to a form of the disease in which symptoms are restricted to those that affect the skin. A patient may be diagnosed with cutaneous lupus, but that does not mean that he or she has SLE, which affects multiple parts of the body. Similarly, if a patient has SLE, it does not mean that he or she will necessarily have cutaneous lupus. However, some cutaneous lupus patients go on to develop SLE, and some SLE patients show signs of cutaneous lupus.
There are three broad types of cutaneous lupus:
The prototypical example of acute cutaneous lupus is the malar rash. Subacute cutaneous lupus (SCLE) usually involves rashes on sun-exposed areas. This generally does not lead to scarring. Lastly, chronic cutaneous lupus can be further subdivided into a number of cutaneous findings including discoid, tumidus, profundus and chilblains. The hallmark condition of chronic cutaneous lupus is discoid lupus erythematosus (DLE).
The malar rash, also known as the butterfly rash, extends from the cheeks across the nasal bridge. About half of patients with SLE develop this rash after ultraviolet light (sun) exposure. This may be difficult to distinguish from other conditions, such as rosacea. One distinguishing feature is that the malar rash usually does not involve the nasolabial fold (the area on the face that runs from the corners of the upper lip to the nose), while rosacea does. The malar rash may develop months or years before the onset of lupus.
SCLE lesions are described as having a scaly red annular (“ring-like”) redness with central clearing. They may also be polycyclic – that is, having the appearance of multiple rings coming together. Another characteristic finding of SCLE is that it is often found in sun-exposed areas. Lastly, patients with SCLE tend to exhibit a certain antibody profile. In addition to a positive antinuclear antibody (ANA), they often exhibit anti-Ro and anti-La antibodies, which are important antibodies that can be seen in lupus. This can be important in pregnant women, because these antibodies can cross the placenta and affect the fetus. In such cases, since the baby is at risk of neonatal lupus, the mother needs to be followed closely and additional treatment considered.
Approximately 50% of patients with SCLE have underlying systemic lupus erythematosus, and about 10% of SLE patients will have SCLE lesions in the skin. In contrast to those diagnosed with SLE, patients with SCLE tend to experience fewer occurrences of cytopenia (decreased numbers of blood cells), serositis (inflammation of tissues lining the lungs, heart, and abdomen), and positive ANA than patients with SLE.
Discoid Lupus Erythematosus (DLE)
Lesions resulting from DLE have a scar-like center that is often surrounded by darker hyperpigmentation, primarily affecting the ears and scalp. These lesions can lead to hair loss, which can be permanent if the DLE is long-standing and loss of hair follicles occurs. Prompt treatment is needed to prevent the scarring process.
DLE affects the face as well, but does not typically affect areas below the neck. DLE may occur in up to 25% of SLE patients and makes up about 75% of all cases of cutaneous lupus. If a patient exhibits localized DLE (only above the neck), there is a very low chance (about 5%) that he or she will develop SLE. About 10% of people with generalized DLE go on to develop SLE, with the interval between onset of SLE ranging from 4 months to 34 years after DLE diagnosis. Seventy percent of people with DLE who go on to develop SLE do so within 5 years of onset. It is important to note, however, that the vast majority of DLE patients do NOT develop SLE.
Some indications that a patient with DLE may go on to develop SLE include:
Other forms of chronic cutaneous lupus include:
A skin biopsy is often required to confirm a diagnosis of cutaneous lupus. Local anesthesia is administered and the physician then performs either a shave biopsy, which involves scraping the skin, or more commonly in lupus, a punch biopsy. To obtain the latter, the medical provider uses a pencil-like device with a hollow hub at the end on the skin of the affected area; a cylinder biopsy of the tissue is removed, and the “punch” is sealed with stiches, leaving a small scar.
Sunlight emits infrared, visible and ultraviolet light. Ultraviolet light, which is further broken down into UVC, UVB, and UVA, is of the greatest concern. The atmosphere filters out UVC. UVA has a longer wavelength, thus, more of it reaches the earth’s surface while more UVB gets filtered out by the atmosphere because of its shorter wavelength. UVA does not get filtered out and can make it through windows or loosely woven clothing. Dr. Lee recommends that patients who spend a lot of time on the road driving get window tinting.
SPF stands for Sun Protection Factor. It measures UVB protection, but it does not measure UVA protection. There is no numerical scale to measure UVA at the moment, so Dr. Lee recommends looking for the label that says “broad spectrum” which is awarded to products that also effectively protect against UVA exposure. It is important to note that SPF is not a linear measurement, thus the higher SPFs may be misleading. Dr. Lee recommends looking for a sunscreen with at least an SPF of 30. An SPF of 30 means the sunscreen filters out roughly 97% of UVB light. An SPF of 60 filters out approximately 98% of UVB light. It is more important to reapply sunscreen every 2 hours on prolonged sun exposure (ie gardening, walking about the city) and use a thick amount than to use a sunscreen with a higher SPF.
He also emphasized that sunscreens should not be used as a means for extending duration of sun exposure. Sun protective hats and clothing can also help protect our skin from the sun. Wide brimmed hats and clothing that exhibit Ultraviolet Protection Factor (UPF) are useful and complement sunscreens during prolonged sun exposure.
Steroid administration can be either topical or intralesional. Topical steroids can be given as creams, ointments, or solutions, based on where it needs to be applied. The typical regimen for topical administration is two times a day. Possible side effects include: atrophy (thinning of the skin), with higher risk of this occurring in the face and occluded sites like the groin, and acne or a rosacea-like flare. With prolonged steroid use in areas close to the eyes, cataracts may develop.
Direct injections into the lesions avoid penetration issues associated with topical steroids, but can be more painful. There is a slightly higher risk of atrophy with a very low risk of infection. The patient must be seen in clinic for treatment, and the typical regimen is once every few weeks.
Topical immunomodulators including Elidel (pimecrolimus) and Protopic (tacrolimus), act like steroids but do not carry the risk of atrophy. These drugs may initially cause a burning sensation. Some evidence suggests a link to malignancies and lymphomas; however, there is a lack of human data for these topical preparations.
As noted, the most common antimalarial used is Plaquenil (hydroxychloroquine), which is dosed by weight and used for persistent rashes. Evidence suggests that early use may delay systemic onset of lupus. Side effects include nausea, vomiting, diarrhea, hemolysis (destruction of red blood cells) in G6PD deficient patients (patients low in this enzyme are more likely to break down red cells as a reaction to Plaquenil), visual abnormality (uncommon), discoloration of skin (bluish-gray), vertigo, weakness, and irritability. However, Plaquenil is generally well-tolerated.
For those rare DLE patients who do not respond to any of these therapies, treatment may extend to methotrexate and then thalidomide.
Dr. Lee concluded his presentation with a few closing thoughts. He encouraged patients to comply with prescribed medications and clinic visits. He also stressed the importance of stopping smoking. According to studies, smoking while taking Plaquenil can decrease its effectiveness. Lastly, he emphasized the importance of avoiding the sun as much as possible and adopting protective measures. His sun protection tips included:
Learn more about the HSS SLE Workshop, a free support and education group held monthly for people with lupus and their families and friends.
Summary completed by Melissa Flores, MPH, LMSW
Ms. Flores was a Masters of Social Work intern and the SLE Workshop Coordinator at the time of this presentation.
Edited by Nancy Novick