During the annual meeting of the Society for Pediatric Dermatology, Amy S. Paller, MD, MS, marveled on the remarkable advances in the treatment of inflammatory skin disorders during the past 2 decades.
Dr. Amy S. Paller
“We’ve come a long way, from disease features being red, thick, and scaly and being treated with nonspecific therapy like topical steroids, keratolytics, and tar, to understanding disease pathogenesis and finding new targeted therapies for inflammatory skin disorders in children,” said Dr. Paller, professor and chair of the department of dermatology at Northwestern University, Chicago. “There are now studies moving forward with gene correction, gene replacement, the gene product replaced, or pathway inhibition to prevent the effects of genetic change.”
Technology is leading the way in generating new therapeutic advances, she continued, beyond traditional “omics” to lipidomics, metabolomics, glycomics, and kinomics. “This has enabled us to find new genetic disorders and their causes, to look at changes in gene expression patterns, and to look at changes in protein expression patterns that give us clues as to how to move forward with better therapy,” she said. “When we’re talking about new insights into pathogenesis-based therapy, we’re talking largely about understanding the pathways that lead to either inflammation or promoting cell proliferation and abnormal differentiation.”
Treating pediatric psoriasis
. “First of all, ask about itch and pain with these patients,” she advised. “Interviews have shown that 61% of children experience some itch, 39% have pain or stinging, and in the ixekizumab trials, 72% had what’s considered meaningful itch, with at least 4 out of 10 (mean intensity 5.3) on the itch numeric rating scale. Little is known about the itch associated with psoriasis and its underlying cause – unrelated to the IL-4/IL-13 pathway activation of atopic dermatitis – but it’s worth asking about. I find that itch of the scalp is especially a problem in psoriasis.”
Physicians should also ask pediatric psoriasis patients about joint pain, because about 1% of them have psoriatic arthritis, which is much less common than in adults, “but important to find and manage,” she added. Dr. Paller recommends the new R-JET rapid joint exam technique, which is accompanied by a three-question survey and body diagram that facilitates identification of true arthritis, “so you can know how quickly to refer”.
Several studies have described an increased risk of metabolic syndrome in adolescents with pediatric psoriasis and now in prepubertal children with the disease. In a recent study of 60 consecutive prepubertal children with psoriasis, 70% of whom had mild disease, 40% were overweight or obese, 53% had central obesity, 27% had high levels of the HOMA-IR (homeostasis model assessment of insulin resistance) despite generally normal levels of fasting glucose, and 30% met criteria for metabolic syndrome.
“This really struck me because our AAD [American Academy of Dermatology] guidelines did not recommend screening for type 2 diabetes in prepubertal children, even if overweight, because the risk is so small,” Dr. Paller said. “This report suggests that we may need to reconsider this recommendation in prepubertal children with psoriasis.”
Meanwhile, the number of medications approved by the Food and Drug Administration and the European Medicines Agency for children with psoriasis who are 6 years of age and above continues to expand, including tumor necrosis factor (TNF) inhibitors, interleukin (IL)-23 inhibitors, and IL-17 inhibitors. Most children can now achieve a PASI 90 within 12 weeks with the IL-23 inhibitor ustekinumab and the IL-17 inhibitors ixekizumab and secukinumab, Dr. Paller said.
In the ixekizumab trial, there are head-to-head comparison data in a European arm that involved the use of etanercept, she said. “What’s most noticeable is the significant difference in those who were able to achieve PASI 90 or above with this IL-17 inhibitor, versus etanercept,” which she added, raises the question of whether aiming for a PASI 75 is adequate, "or should we strive for PASI 90?” A pediatric psoriasis study published in 2020 found that the greatest improvement in quality of life was associated with a PASI 90 and use of systemic treatments.
Looking forward, phase 3 clinical trials are underway in pediatric patients with moderate to severe psoriasis for guselkumab, tildrakizumab, risankizumab, certolizumab, bimekizumab, and brodalumab. “The cost of all of these biologics is high, however. I remind everyone that we still have methotrexate,” she said. “The risk of side effects with our low-dose methotrexate treatment for psoriasis remains low, but methotrexate doesn’t hit these [high] PASI numbers and it’s much slower in its onset than biologics.”
Dr. Paller disclosed that she is a consultant to and/or an investigator for AbbVie, Arena, Bausch, Bristol Myers Squibb, Dermavant, Eli Lilly, Incyte, Forte, LEO Pharma, LifeMax, Pfizer, RAPT Therapeutics, Regeneron, and Sanofi.
Commentary by Robert Sidbury, MD, MPH
Dr. Paller reminds us of some essential features of pediatric psoriasis:
• It can hurt. Ask your patients if it does.
• It can itch. Look for excoriations, especially in the scalp.
• It is often associated with metabolic syndrome, so check relevant biometrics and labs, and consider coincident insulin resistance.
• Our traditional clinical trial target of PASI75, or a 75% reduction in body surface area involvement, is just not good enough. Studies have shown that the most meaningful quality-of-life gains come at PASI90 or above.
• With our newer biologics, such as IL-12/23 blockers (for instance, ustekinumab) and IL-17 blockers (for example, ixekizumab and secukinumab), PASI90 and better is a reasonable expectation, not a pipe dream.
Dr. Sidbury is chief of dermatology at Seattle Children's Hospital and professor, department of pediatrics, University of Washington, Seattle. He is a site principal investigator for dupilumab trials, for which the hospital has a contract with Regeneron.
This article was updated 6/16/22.