eTable. Association of obesity, metabolic abnormalities, and pediatric psoriasis
Becker L, Tom WL, Eshagh K, Benjamin LT, Paller AS. Excess Adiposity Preceding Pediatric Psoriasis. JAMA Dermatol. 2014;150(5):573-574. doi:10.1001/jamadermatol.2014.324
As for adult psoriasis, pediatric psoriasis has recently been associated with obesity, increased waist circumference percentiles, and waist-to-height ratios, and metabolic laboratory abnormalities1- 3 (eTable in Supplement). Although obesity could theoretically result from the functional limitations and psychosocial impact of psoriasis, adult females self-reported that obesity developed before psoriasis4 and high body mass index (BMI) (calculated as weight in kilograms divided by height in meters squared) in adolescent girls preceded psoriasis hospitalization in adults.5 To our knowledge, whether obesity precedes pediatric psoriasis or psoriasis leads to childhood obesity has not been addressed. In a pilot study with a new cohort, we addressed the temporal association of pediatric psoriasis and increased adiposity in 27 overweight and obese children with psoriasis.
See the eMethods in the Supplement. The study was approved by the institutional review board at all centers, and written informed consent was obtained from each participant prior to the study initiation, adhering to the Helsinki Guidelines. The BMI percentiles of overweight (85th ≤ BMI percentile < 95th) and obese (BMI percentile ≥ 95th) children with psoriasis at 3 pediatric dermatology referral centers were determined at onset of psoriasis, 1 and 2 years before (required for inclusion), and, if available, 1 and 2 years after psoriasis onset.
Of 37 serially examined and enrolled children with psoriasis with excess adiposity, 27 had sufficient data sets from pediatricians to meet inclusion criteria (Table); incomplete data reflected lack of an annual check, transfer of pediatrician, and/or lack of pediatrician cooperation. The mean BMI percentile at enrollment was 96th, with 30% classified as overweight and 70% as obese. Involved body surface area (BSA) was greater in obese children ( n = 9 [50%] with a BSA > 20%) than in overweight children (n = 1 [17%] with BSA > 20%) (P = .001). Overall, 25 of 27 patients [93%]) were overweight or obese at onset and at 1 and 2 years before onset of psoriasis (Table). One and 2 years after onset, 24 (91.7%) and 22 (100%), respectively, were overweight or obese. One of the 2 patients not overweight or obese at onset showed a steep BMI percentile gain within 1 year after onset (from 56th to 83rd percentile) and was overweight 1 years after onset (90th percentile); the other’s BMI increased from the 75th (onset) to the 94th percentile at 1 year after onset and then to the 95th percentile 2 years after onset. Timing of onset of psoriasis vs excess adiposity did not correlate with being overweight vs obese, birthweight, scalp or nail involvement, history of arthritis, or family history of psoriasis or hyperlipidemia. However, children with familial obesity developed psoriasis earlier than those without (mean age, 7.0 vs 10.3 years at onset, respectively; P = .02). After psoriasis onset, 2 patients showed a decline in BMI percentile, one from the 90th to 85th percentile and the other from the 97th to 94th percentile.
In our pilot study, being overweight or obese preceded psoriasis by at least 2 years in 93% of children with psoriasis. While chronically elevated circulating proinflammatory cytokines (eg, interleukin 6 and tumor necrosis factor) and adipokines characterize both obesity and psoriasis, the reason for the delayed psoriasis onset (mean, 4.6 years) remains unclear. We also demonstrate that children with psoriasis with increased adiposity have a high percentage of immediate family members with obesity (48%) and psoriasis (41%), which occurs in 34% and 30%, respectively, of children overall with psoriasis.1 Weight-loss programs are more successful in children 6 to 12 years old than in adolescents and when healthy diet and physical activity become a family activity. We recommend early lifestyle counseling of families with psoriasis (especially those with obesity). Whether weight control reduces pediatric psoriasis severity also deserves investigation.
This pilot study was limited by being retrospective. A prospective, collaborative study between local pediatricians and pediatric dermatologists (eg, the Pediatric Dermatology Research Alliance) is warranted to further address the temporal relationship of psoriasis and obesity. Given the latency period of 2 or more years between obesity and psoriasis onset and uncommon occurrence of pediatric psoriasis (<1% of children2,3 and <40% having excess adiposity1), a cohort of more than 10 000 children in a 5-year longitudinal analysis would be required to capture data for 27 overweight or obese children with psoriasis.
Accepted for Publication: February 13, 2014.
Corresponding Author: Amy S. Paller, MD, Department of Dermatology, 676 N St. Clair, Ste 1600, Chicago, IL 60611 (email@example.com).
Published Online: April 2, 2014. doi:10.1001/jamadermatol.2014.324.
Author Contributions: Drs Becker and Paller had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Eshagh, Paller.
Acquisition of data: All authors.
Analysis and interpretation of data: Becker, Eshagh, Paller.
Drafting of the manuscript: Becker, Eshagh, Paller.
Critical revision of the manuscript for important intellectual content: All authors.
Administrative, technical, and material support: Becker, Tom, Eshagh, Benjamin.
Study supervision: Eshagh, Paller.
Conflict of Interest Disclosures: None reported.
Funding/Support: Dr Tom’s salary related to inflammatory skin disease research is supported, in part, by Career Development Award K23AR060274 from the National Institutes of Health/National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS).
Role of the Sponsor: The NIAMS had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.
Additional Contributions: Katherine Mercy, MD, assisted with data collection; Bing Bing (Sarah) Weitner, MS, with statistical analysis; and Dennis West, PhD, with study supervision; all are from Northwestern University Feinberg School of Medicine and are salaried.