Adapted from a presentation at the SLE Workshop at Hospital for Special Surgery
Skin conditions associated with lupus can be significant and play a major role in both the diagnosis of lupus and its clinical course.
Of the 11 criteria set by the American College of Rheumatology in 1997, four are skin-related. These include:
Two more recent sets of criteria, both of which build upon the 1997 ACR criteria, have since been established:
Although more complicated than the 1997 ACR criteria, both SLICC and EULAR incorporate the above four cutaneous (skin-related) criteria but also emphasize nonscarring alopecia and subacute cutaneous lupus erythematosus (SCLE). The major role that cutaneous findings play in all three of these criteria highlights the importance of cutaneous symptoms in lupus.
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 the patient has SLE, which can affect multiple organ systems of the body. In fact, the overwhelming majority of patients who present with discoid lupus will not develop systemic lupus. Similarly, although many SLE patients develop cutaneous disease (some studies estimate this to be about 80% of patients over the course of their lupus), it does not mean all patients will develop cutaneous lupus. It follows that only the minority of cutaneous lupus patients go on to develop SLE, but that many SLE patients will show signs of cutaneous lupus at some point.
Cutaneous lupus can be divided into three groups:
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. 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 exhibit SCLE lesions at one point. In contrast to those diagnosed with SLE, patients with SCLE tend to experience fewer occurrences of cytopenia (decreased numbers of blood cells), and serositis (inflammation of tissues lining the lungs, heart, and abdomen) than patients with SLE.
Discoid lupus erythematosus (DLE)
Lesions resulting from DLE have a scar-like centers that are often surrounded by darker hyperpigmentation, and these primarily affect 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 four months to 34 years after DLE diagnosis. Seventy percent of people with DLE who go on to develop SLE do so within five 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 the following:
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.
Sun exposure can lead to an exacerbation of cutaneous lupus. As such, sun protection is paramount. 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 and penetrates through clouds, windows and loosely woven clothing. Consequently, lupus patients should practice safe sun practices even on cloudy days or if they are sitting indoors next to windows. We have had window tint applied to both office windows and automobiles of our patients.
We recommend sunscreens with at least an SPF of 30 and an SPF is adequate protection. SPF stands for sun protection factor. It measures UVB protection, but it does not measure UVA protection. As there is currently no numerical scale to measure UVA, one should look for the “broad spectrum” label, 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.
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, which is not a significant improvement over SPF 30. It is important to reapply sunscreen every two hours during prolonged sun exposure (such as gardening, going for walks) and to apply a thick amount with each application.
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 easy to use and complement sunscreens during prolonged sun exposure.
Steroid administration can be either topical or intralesional. Topical steroids can be formulated as creams, ointments, gels or solutions, and are chosen largely based on the anatomic sites to which they will 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. Cataracts and glaucoma are rare side effects that can arise after prolonged steroid use in areas close to the eyes.
Direct injections into the lesions avoid penetration issues associated with topical steroids. The patient must be seen in clinic for treatment as opposed to home application of topical steroids and is typically administered on a monthly basis.
Topical immunomodulators including pimecrolimus and tacrolimus, are anti-inflammatory like steroids but do not carry the risk of atrophy, cataracts or glaucoma. These drugs may initially cause a burning sensation, but this usually subsides after a few applications. Some evidence suggests a link to malignancies and lymphomas; however, this data is primarily derived from oral preparations and not topical preparations.
As noted, the most common antimalarial used is hydroxychloroquine, which is dosed by weight and used to prevent and treat cutaneous lupus. Evidence suggests that early use may delay systemic onset of lupus. Side effects include nausea, vomiting, diarrhea, hemolysis (destruction of red blood cells), visual abnormality (uncommon), retinal damage, bluish-grey discoloration of skin, vertigo, and weakness. However, hydroxychloroquine is generally well-tolerated. Given the potential eye side effects, regular screening with an ophthalmologist is recommended prior to initiation and during therapy.
For those rare DLE patients who do not respond to any of these therapies, treatment may extend to methotrexate, thalidomide or other immunosuppressants.
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 smoking cessation. According to studies, smoking while taking hydroxychloroquine can decrease its effectiveness. Lastly, he again emphasized the importance of safe sun practices. 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 written by
Melissa Flores, MPH, LCSW
Department of Social Work Programs
Ms. Flores was a Masters of Social Work intern and the SLE Workshop Coordinator at the time of this presentation.