“I think there is a lot of testing without appropriate clinical context or pre-test concern for disease,” he says. “It is all about clinical context [and titer]. There are lots of other diseases that cause a positive ANA that are not lupus. We need to get the message out to primary care and dermatologists: A positive ANA does not automatically [equate to] systemic connective tissue disease. [Dermatologists] need to be really judicious in ordering ANAs, unless the clinical suspicion is reasonable.”
Another common mistake: Ordering a beta-2 microglobulin (B2M) test when “dermatologists really mean to order a beta-2 glycoprotein 1 antibody test,” Dr. Merola adds. “It’s nuanced, but it is something a rheumatologist would know. The B2M is a totally unrelated test, and ordering the B2M is a common mistake when evaluating antiphospholipid antibodies in the dermatology patient presenting with vasculopathy.”
Identify & Treat Skin Rashes Caused by Anti-TNF Inhibitors
Anti-TNF drugs can actually cause the skin rashes they are meant to treat, which can be confusing and lead to unnecessary changes in otherwise successful therapy plans.2 Drug-induced psoriasiform dermatitis is one not-so-uncommon example. Dr. Merola says rheumatologists should also be familiar with less-common skin rashes, including a type of anti-TNF induced skin lupus (subacute cutaneous lupus) and dermatomyositis.
“It is important for rheumatologists to recognize those [conditions] and feel comfortable” treating them, Dr. Merola says. “And it is super important for dermatologists to understand that a large majority of these patients, who are on these anti-TNF drugs for an extended period, can actually develop a positive ANA and other abnormal rheumatologic lab testing in the absence of any concerning systemic disease.”
Recognize Psoriasis Is More Than a Cosmetic Issue
Putting on his dermatologist hat, Dr. Merola says some rheumatologists don’t appreciate how psoriasis affects quality of life. Focused on controlling the joint disease, “they sometimes overlook or underplay the patients’ skin disease,” he says.
“A whole host of studies show the quality-of-life impact of the skin component is tremendous, in some cases even more so than the joint disease in patients who have both joint and skin disease,” Dr. Merola explains. “To drive home the point, one study demonstrated that up to 10% of younger patients may even have contemplated suicide due to their psoriasis, which is an extreme example to underscore how impactful [psoriasis] is on quality of life.”3
He suggests taking exam time to identify inverse (intertriginous) psoriasis, often found in the armpits, gluteal cleft of the buttocks, the groin or other body-fold areas.
