AT THE EADV CONGRESS
GENEVA (FRONTLINE MEDICAL NEWS) – Pediatric psoriasis is associated with sharply increased risks of selected autoimmune diseases, according to a cross-sectional study encompassing every child and adolescent in Denmark.
Even though the absolute risk of many of these conditions remains rare in childhood, clinicians should keep these associations in mind because they can greatly add to the total disease burden. In particular, we advise focusing on extracutaneous symptoms when treating psoriasis in children,” Christoffer Blegvad, MD, said at the annual congress of the European Academy of Dermatology and Venereology.
He presented a cross-sectional study in which Denmark’s vaunted system of comprehensive national registries was harnessed to obtain health information on all individuals under age 18 years living in Denmark as of the end of 2012. The study population comprised 1,925 children and adolescents with dermatologist-diagnosed psoriasis, including those with psoriasis mild enough to be managed with topical therapies, and 1,194,712 youths without psoriasis.
In a first-pass unadjusted analysis, the psoriasis patients were at significantly increased risk for all nine of the autoimmune diseases examined. When the investigators adjusted for age, sex, and an individual’s health care utilization as reflected in his or her number of dermatology visits, the children and adolescents with psoriasis remained at tenfold increased risk for comorbid psoriatic arthritis, 6.6-fold risk for rheumatoid arthritis, 4.8-fold risk for vitiligo, and smaller yet significantly increased risks for several other autoimmune diseases, compared with individuals without psoriasis.
“What is especially interesting, I think, is there is a sort of clustering effect for autoimmune diseases in psoriasis,” said Dr. Blegvad of the University of Copenhagen.
Indeed, while the presence of pediatric psoriasis was associated with an adjusted 4.4-fold increased risk of having at least one autoimmune disease, psoriasis patients with one of the selected autoimmune diseases were at 7.3-fold greater risk of having two or more autoimmune diseases compared with individuals with one autoimmune disease who didn’t have psoriasis.
This is the first study to show such a clustering effect in either pediatric or adult psoriasis patients. The finding highlights the complex genetic underpinnings of psoriasis, which has previously been shown to share genetic susceptibility loci with inflammatory bowel disease and various other autoimmune diseases, Dr. Blegvad noted.
A small caveat: The psoriatic arthritis category also included individuals with juvenile idiopathic arthritis and juvenile psoriatic arthritis, because the clinical signs and symptoms of the three disorders often are difficult to distinguish in young patients.
Dr. Blegvad reported having no financial conflicts regarding the study, funded by Herlev and Gentofte Hospital and the LEO Foundation.