When managing conditions that involve both skin and joint symptoms, “sometimes we have to kill 2 birds with 2 stones,” Joseph Merola, MD, said. Additionally, he suggested that combination of therapies may be needed to adequately address psoriatic arthritis (PsA) and other conditions that may mimic psoriatic disease.

Dr Merola is an associate professor at Harvard Medical School and is affiliated with Beth Israel Deaconess Medical Center in Boston, Massachusetts. He is triple-board-certified in dermatology, rheumatology, and internal medicine.

He described the case of a patient referred to his combined dermatology-rheumatology clinic of a 20-year-old woman with what appeared to be psoriatic plaques limited to the buttocks. She also complained of increasing joint paint and fatigue. Treatment with methotrexate provided no improvement and the patient did not tolerate the medication well. A short course of adalimumab also yielded no change in her symptoms.

“Why aren’t these lesions improving?” Dr Merola asked. Additional diagnostic procedures provided the answer: the patient was diagnosed with cutaneous T cell lymphoma (CTCL). Her joint pain and fatigue were likely attributable to fibromyalgia, he noted.

Citing another case of CTCL, he remarked that such cases in which patients do not respond to tumor necrosis factor inhibitors (TNFis) or even have worsening of symptoms, “Invariably come to us in the combined clinic.”

Several dermatologic conditions are often mistaken for psoriasis (PsO), Dr Merola stated. He illustrated cases in which patient had been diagnosed with PsO, but then were found to have atopic dermatitis, contact dermatitis, or other conditions.

Another clue that a condition may not be PsO is when the condition is photoexacerbated, he said. A patient with several symptoms consistent with PsO but whose skin was more affected in areas exposed to light was found to have subacute cutaneous lupus.

Patients with hand dermatitis and arthritis “can be very tricky,” he said. Biopsies of palms and soles typically are not very helpful and there are many causes for hand dermatitis, including atopic dermatitis. He also pointed out differences between psoriatic lesions and seborrhetic dermatitis.

In another case, Dr Merola described a 65-year-old man with a history of minimal PsO but moderate to severe PsA. There was also a family history of PsO and PsA. “Interestingly—and these are not mutually exclusive—he also has a history of moderate to severe eczematous dermatitis and atopic dermatitis in his childhood.”

The patient had been through 2 TNFis with no improvement in his skin condition, which Dr Merola noted was not surprising because “TNFis don’t treat eczema.” Methotrexate yielded only marginal improvement in skin and joints.

“At this point, we’re a little up against the wall, wondering how we can get this patient under good control.” In this case, the patient chose to add an oral JAK inhibitor, which effected skin clearance and marked improvement in his joint disease, as well, Dr Merola reported.

A 54-year-old woman whose PsA joint disease had been well controlled on TNFi therapy experienced worsening skin disease, Dr Merola stated. The patient was quite happy with the TNFi and did not want to change that therapy. However, the skin disease affected the genital area and frontal scalp, which had a deeper impact on her quality of life.

“Just a reminder that we as rheumatologists can only optimize patients’ quality of life by optimizing both their joint and skin disease,” he emphasized. “I really believe we can own and help treat some of this first-line and breakthrough psoriasis in patients we’re otherwise treating with systemics for their PsA.” The addition of topicals can be effective but somewhat complicated, he noted, requiring 2 or 3 different agents for different areas of the body.

Dr Merola reported that there are 2 recently approved nonsteroidal topical agents that may help reduce the complexity: the PDE4 inhibitor roflumilast does not cause skin atrophy or thinning, is well tolerated and has a favorable safety profile and good efficacy data. “It may be easier for us to approach a patient with a single agent to use on any area.”

Tapinarof is another novel mechanism that can be used on any body site safely, he said.

Dr Merola noted, “something like 80% of patients present with skin disease before joint disease and there are estimates that 10-15% have joint disease before psoriasis. I think that’s probably an overestimate. I believe if we had patients undress and really went looking, we might find evidence of psoriasis.” He urged rheumatologists to think about searching for inverse or intertriginous psoriasis in skin folds, noting that approximately 23% of patients have some inverse PsO. “This is not uncommon” and it is one of the subsets at higher risk of developing PsA.

“I think it’s important for us as rheumatologists to not just look at skin psoriasis data through our PsA lens but also get to know a little bit the primary psoriasis data,” and learn how the agents work with the skin as well as joints.

The interleukin (IL)-23 and IL-17 mechanisms tend to fall at the top of the list of therapies for achieving skin clearance.

He related the case of a patient with severe skin and joint PsA who has been through a wide variety of therapies, including JAK inhibitors, TNFis, methotrexate and other biologics. The patient ultimately decided that the skin disease was the most bothersome and chose to go back on an IL-17 inhibitor, which controlled her skin disease but her joint disease remained poorly controlled.

“I know this isn’t something we routinely do, but I want to introduce the wild and crazy concept of considering combination therapy in these extreme and really severe cases,” Dr Merola said. This patient remained on her IL-17 and added a JAK inhibitor, and is doing quite well.” He noted that the patient received detailed counseling on risks of infection and other complications, but the combination is working to control both her skin and joint disease.

He referenced the VEGA study of patients with ulcerative colitis treated with both an IL-23 and a TNFi and showed marked improvement. “Our IBD colleagues are starting to pave the way with these concepts. So stay tuned for that.

—Rebecca Mashaw
Reference:
Merola, JF. Challenges in psoriatic disease: divergent skin and joints. Presented at: American College of Rheumatology Convergence. Philadelphia, Pennsylvania. November 12, 2022.