The study, “Psoriasis Associated with Tumor Necrosis Factor‐Alpha Inhibitors in Children with Inflammatory Diseases,” was published in the journal Arthritis Care & Research.
Psoriasis is characterized by rapid buildup of skin cells, resulting in red or scaly patches of skin that can be itchy and painful.
TNF-alpha is a molecule that promotes inflammation and has been implicated in JIA and other diseases. As such, therapies that block, or inhibit, the activity of this molecule — TNF inhibitors — have been increasingly used. This has been associated with the development of psoriasis.
However, the incidence of this skin condition among people using TNF inhibitors for JIA and two other inflammatory disorders — chronic noninfectious osteomyelitis (CNO) and inflammatory bowel disease (IBD) — is still unknown.
To address this gap, researchers reviewed clinical data for children with any of these three conditions who were treated with a TNF inhibitor at Children’s Hospital of Philadelphia between 2008 and 2018. The TNF inhibitors included Enbrel (etanercept), infliximab (marketed as Remicade, Remsima, and Inflectra), Humira (adalimumab), Cimzia (certolizumab), and Simponi (golimumab)
Among the group of 4,111 children, 1,614 (39%) had been treated with a TNF inhibitor (mean age 12 years), while the remaining 2,497 (61%) had not (11 years). Most children (74%) had IBD, 24% had JIA, and 2% had CNO. The median follow-up time was about two years.
Results revealed 83 cases of psoriasis, 58 of them in children who had been treated with a TNF inhibitor. Psoriasis was more frequent in patients who had been treated with a TNF inhibitor compared to children who had not — 12.3 vs. 3.8 per 1,000 person-years. Person-years is a measure that sums actual follow-up duration in each patient and is higher with more years in study.
After accounting for factors such as age, sex, use of the immunosuppressant methotrexate, and obesity (reported as a risk factor for psoriasis), use of a TNF inhibitor was associated with more than 3.8 times the risk of developing psoriasis.
Broken down by disease type, TNF inhibitors increased the risk of having psoriasis 4.52 times in children with IBD and 2.9 times in children with JIA.
The researchers noted that the rates of psoriasis in the group not treated with a TNF inhibitor were still higher than those in unaffected children. This suggests that conditions such as JIA and IBD may increase the risk of developing psoriasis, a risk exacerbated by the use of TNF inhibitors.
“In conclusion, this study demonstrates that children with IBD, JIA, and CNO had an increased rate of psoriasis compared to the general pediatric population, with the highest rate in those with [TNF-alpha inhibitor] exposure,” the researchers stated.
Long-term studies using large patient registries are still needed, they added.