ATLANTA – in a at the Children’s Hospital of Philadelphia.
The finding confirms a clinical suspicion that biologics can cause psoriasis in children, just as has been shown in adults, said lead investigator, a rheumatology fellow at the hospital when she conducted the study, but now a pediatric rheumatologist at Vanderbilt University, Nashville, Tenn. The study was recently published in .
“I don’t think this will change my prescribing habits” because tumor necrosis factor inhibitors (TNFi) are so useful, but “what this will change is how much information I give to families about the risk of psoriasis, especially in kids with a family history,” which also predisposed children in theto psoriasis, Dr. Buckley said . “Anecdotally, psoriasis has not been part of the traditional risk-benefit conversation with families. This has added that to my” discussion, he added.
TNFi “psoriasis can be a really big deal for these children, especially in adolescence. They don’t want to go to school and things like that. Children and parents often prioritize [it] over the underlying disease,” she said.
For now, how to best manage TNFi psoriasis is uncertain. Children often are in remission when it starts, and a decision has to be made whether to discontinue treatment, reduce the dose, or add something for the psoriasis. There are no clear answers at the moment. “This is the beginning of the beginning of studies looking at this. It just proves that there actually is a problem,” Dr. Buckley said at the annual meeting of the American College of Rheumatology.
About three-quarters of the children had inflammatory bowel disease, and most of the rest had juvenile idiopathic arthritis. Just 2% had chronic nonbacterial osteomyelitis. Billing codes were used to confirm diagnosis, new-onset psoriasis, and incident TNFi exposure, defined as at least one prescription for adalimumab, etanercept, or infliximab.
Overall, 1,614 children (39%) were treated with a TNFi and 2,497 (61%) were not. There were 58 cases of psoriasis in the TNFi group for an incidence ratio of 12.3 cases per 1,000 person-years, and a standard IR – observed psoriasis cases over expected cases in the general pediatrics population – of 30.
There were 25 cases among children not treated with a TNFi, for an IR of 3.8 per 1,000 person-years and SIR of 9.3.
In the end, TNFi exposure was associated with a marked increase in psoriasis risk (hazard ratio, 3.84; 95% confidence interval, 2.28-6.47; P less than .001). Family history was positive in 8% of subjects and was a known risk factor; it was the only other independent predictor (HR, 3.11; 95% CI, 1.79-5.41; P less than .001).
Obesity, which was linked in previous studies to psoriasis and was higher in the non-TNFI group, did not influence risk, nor did methotrexate, which was also used more commonly in the TNFi group. “We thought that including patients on methotrexate, which is a treatment for psoriasis, might have altered the outcomes, but it didn’t seem to make any difference in developing psoriasis,” Dr. Buckley said.
It’s possible that children on a TNFi had higher disease activity, and that in itself increased the risk of psoriasis, but there isn’t an association in the literature between high disease activity and psoriasis, she said. In past reports, TNFi-induced psoriasis was most likely to occur in adults who were in disease remission.
Subjects were aged about 11 years on average and about equally split between boys and girls; three-quarters were white. Children previously diagnosed with psoriasis were excluded. Average follow up was about 2 years.
The National Institutes of Health funded the work. The investigators didn’t report any relevant disclosures.
SOURCE: Buckley L et al. Arthritis Rheumatol. 2019;71(suppl 10),