Dermatology pearls for the rheumatologist: cutaneous lupus, dermatomyositis
DESTIN, Fla. — In a session here at Congress of Clinical Rheumatology, Joseph F. Merola, MD, MMSc, of Harvard Medical School and Brigham and Women’s Hospital, shared the dermatology approach to cutaneous lupus erythematosus, as well as valuable skin elements of dermatomyositis.
“As you know, it is sometimes challenging not only to get your patient — lupus or otherwise — in to see a dermatologist, but also it can be a particular challenge finding a dermatologist who is comfortable and willing to treat some of our patients with more [complex or tricky disease], ... hopefully this will demystify it a bit,” he said.
Cutaneous lupus erythematosus (CLE) can be a confusing area, he added. To help guide clinicians, he and colleagues are working on classification criteria for discoid lupus using 12 items that cover the morphology, histopathology and location of disease. The final classification criteria set will be presented with validation at the World Congress of Dermatology in Milan this June.
In the meantime, Merola provided a summary of the three basic elements of CLE to look for on the pathology report from skin biopsy: lymphocytic infiltrate, interface dermatitis and dermal mucin deposition. He added that, depending which study you look at, isolated CLE is as prevalent — if not more prevalent — than systemic disease.
“It may sound surprising, but these people are probably presenting more to the dermatologist. It’s important because it raises a few different questions about that phenotype,” he said.
A dermatologist’s approach to CLE
Merola offered a look at the dermatologist’s approach to patients with CLE, which includes first-line therapy with sunscreen and photoprotection; steroids, including topical, intra-lesional and systemic; topical calcineurin inhibitors like tacrolimus and pimecromilus; and “the anti-malarial march” — hydroxychloroquine, or among folks who fail hydroxychloroquine, adding quinacrine or changing to chloroquine.
Second-line treatments include methotrexate, mycophenolate, thalidomide and lenalidomide, dapsone and retinoids.
Refractory disease is not uncommon among patients with CLE; in fact, about 10% of patients are refractory to all treatments. What’s more, 50% of refractory patients require treatment escalation beyond topical and antimalarial treatments to biologics or immunosuppressive options, according to Merola.
Skin elements of dermatomyositis
In terms of dermatomyositis, while Merola said there wasn’t any new knowledge he could impart, he did focus on skin elements of value to the audience. In clinically amyopathic dermatomyositis, the subtypes to be familiar with are based on two autoantibody profiles, with a cluster of clinical phenotypes linked with these autoantibodies. The subtypes are anti-MDA5, which is present in East Asian populations, and anti-TIF1-gamma, which is more prevalent in white patients. Hallmarks of anti-MDA5 phenotype include ulcers/palmar papules, increased risk for interstitial lung disease, vasculopathy, a lower risk for cancer and alopecia. For anti-TIF1-gamma phenotype, clinical characteristics include an increased cancer risk, low risk for interstitial lung disease, poikiloderma and “classic skin disease.”
Merola pointed out that in 2013, a study reported that skin ulcers were a predictive and prognostic factor for acute or subacute interstitial lung disease among patients with anti-MDA5 phenotype, a connection that could affect treatment decisions.
He offered a look at skin treatment pearls for patients with dermatomyositis.
“These patients are incredibly sun sensitive and the reason that’s so important is that they’re probably not doing as good a job as they could be with photoprotection,” he said, stressing the importance of good sun protection, even in winter, and suggesting patients apply and reapply high-SPF, physically blocking sunscreens and wear high UPF, lightweight protective clothing.
In addition, methotrexate and mycophenolate are go-to therapies for dermatomyositis, while topicals and antimalarials are not as effective. – by Stacey L. Adams
Merola JF. Dermatology for the rheumatologist; May 2-5, 2019; Destin, Florida.
Disclosures: Merola reports he is a consultant and/or investigator for AbbVie, Aclaris, Almirall, Biogen, Celgene, Dermavant, Eli Lilly, GlaxoSmithKline, Incyte, Janssen, Leo Pharma, Merck Research Laboratories, Novartis, Pfizer, Samumed, Sanofi Regeneron, Sun Pharma and UCB.