The clinical features of pediatric psoriasis warrant further attention. A national study was conducted to determine the prevalence of scalp and nail involvement and a history of guttate psoriasis at onset according to age, sex, and disease severity. One hundred eighty-one children ages 5 to 17 years with plaque psoriasis were enrolled in a multicenter, cross-sectional study. Subjects and guardians were asked about a history of scalp and nail involvement and whether the initial presentation was guttate. Peak psoriasis severity was assessed and defined historically as mild psoriasis (MP) or severe psoriasis (SP) according to the Physician's Global Assessment and body surface area measures. One hundred forty-three (79.0%) subjects reported a history of scalp involvement, and 71 (39.2%) described a history of nail involvement. Boys were less likely than girls to report a history of scalp involvement (odds ratio [OR] = 0.40, 95% confidence interval [CI] = 0.19-0.84) but more likely to have had nail involvement (OR = 3.01, 95% CI = 1.62-5.60). Scalp and nail involvement was not related to psoriasis severity. In contrast, subjects with SP (35.9%) more often reported a history of guttate lesions than did those with MP (21.8%) (p = .02). Antecedent streptococcal infection was more common in children with guttate than those with plaque psoriasis at onset (p = .02) but did not correlate with severity. Sex-related differences in scalp and nail involvement suggest koebnerization. Preceding streptococcal infection predicts guttate morphology but not severity, and initial guttate morphology is associated with eventual greater severity of disease. More aggressive monitoring and management should be considered for guttate psoriasis, given its later association with more severe disease.

Psoriasis is a chronic inflammatory immune-mediated disorder affecting the skin and other organs including joints. Over 1,300 transcripts are altered in psoriatic involved skin compared with normal skin. However, to our knowledge, global epigenetic profiling of psoriatic skin is previously unreported. Here, we describe a genome-wide study of altered CpG methylation in psoriatic skin. We determined the methylation levels at 27,578 CpG sites in skin samples from individuals with psoriasis (12 involved, 8 uninvolved) and 10 unaffected individuals. CpG methylation of involved skin differed from normal skin at 1,108 sites. Twelve mapped to the epidermal differentiation complex, upstream or within genes that are highly upregulated in psoriasis. Hierarchical clustering of 50 of the top differentially methylated (DM) sites separated psoriatic from normal skin samples with uninvolved skin exhibiting intermediate methylation. CpG sites where methylation was correlated with gene expression are reported. Sites with inverse correlations between methylation and nearby gene expression include those of KYNU, OAS2, S100A12, and SERPINB3, whose strong transcriptional upregulation is an important discriminator of psoriasis. Pyrosequencing of bisulfite-treated DNA from skin biopsies at three DM loci confirmed earlier findings and revealed reversion of methylation levels toward the non-psoriatic state after 1 month of anti-TNF-α therapy.

Dupilumab is a fully human antibody to interleukin-4 receptor α that improves the signs and symptoms of moderate to severe atopic dermatitis (AD). To determine the effects of dupilumab on Staphylococcus aureus colonization and microbial diversity on the skin, bacterial DNA was analyzed from swabs collected from lesional and nonlesional skin in a double-blind, placebo-controlled study of 54 patients with moderate to severe AD randomized (1:1) and treated with either dupilumab (200 mg weekly) or placebo for 16 weeks. Microbial diversity and relative abundance of Staphylococcus were assessed by DNA sequencing of 16S ribosomal RNA, and absolute S. aureus abundance was measured by quantitative PCR. Before treatment, lesional skin had lower microbial diversity and higher overall abundance of S. aureus than nonlesional skin. During dupilumab treatment, microbial diversity increased and the abundance of S. aureus decreased. Pronounced changes were seen in nonlesional and lesional skin. Decreased S. aureus abundance during dupilumab treatment correlated with clinical improvement of AD and biomarkers of type 2 immunity. We conclude that clinical improvement of AD that is mediated by interleukin-4 receptor α inhibition and the subsequent suppression of type 2 inflammation is correlated with increased microbial diversity and reduced abundance of S. aureus.

Objective

To investigate the relationship of excess and central adiposity with pediatric psoriasis severity.

Design, setting, and participants

Multicenter, cross-sectional study of 409 psoriatic children. Psoriasis was classified as mild (worst Physician's Global Assessment score ≤3 with body surface area ≤10%) or severe (worst Physician's Global Assessment score ≥3 with body surface area >10%). Children were enrolled from 9 countries between June 19, 2009, and December 2, 2011.

Main outcome measures

Excess adiposity (body mass index percentile) and central adiposity (waist circumference percentile and waist to height ratio).

Results

Excess adiposity (body mass index ≥85th percentile) occurred in 37.9% of psoriatic children (n=155) vs 20.5% of controls (n=42) but did not differ significantly by severity. The odds ratio (95% CI) of obesity (body mass index ≥95th percentile) overall in psoriatic children vs controls was 4.29 (1.96-9.39) and was higher with severe (4.92; 2.20-10.99) than with mild (3.60; 1.56-8.30) psoriasis, particularly in the United States (7.60; 2.47-23.34, and 4.72; 1.43-15.56, respectively). Waist circumference above the 90th percentile occurred in 9.3% of the control (n=19), 14.0% of the mild psoriasis (n=27), and 21.2% of the of severe psoriasis (n=43) participants internationally; this incidence was highest in the United States (12.0% [n=13], 20.8% [16], and 31.1% [32], respectively). Waist to height ratio was significantly higher in psoriatic (0.48) vs control (0.46) children but was unaffected by psoriasis severity. Children with severe psoriasis at its worst, but mild at enrollment, showed no significant difference in excess or central adiposity from children whose psoriasis remained severe.

Conclusions

Globally, children with psoriasis have excess adiposity and increased central adiposity regardless of psoriasis severity. The increased metabolic risks associated with excess and central adiposity warrant early monitoring and lifestyle modification.

Trial registration

clinicaltrials.gov Identifier: NCT00879944

Psoriasis is a common immune-mediated disorder that affects the skin, nails and joints. To identify psoriasis susceptibility loci, we genotyped 438,670 SNPs in 1,409 psoriasis cases and 1,436 controls of European ancestry. We followed up 21 promising SNPs in 5,048 psoriasis cases and 5,041 controls. Our results provide strong support for the association of at least seven genetic loci and psoriasis (each with combined P < 5 x 10(-8)). Loci with confirmed association include HLA-C, three genes involved in IL-23 signaling (IL23A, IL23R, IL12B), two genes that act downstream of TNF-alpha and regulate NF-kappaB signaling (TNIP1, TNFAIP3) and two genes involved in the modulation of Th2 immune responses (IL4, IL13). Although the proteins encoded in these loci are known to interact biologically, we found no evidence for epistasis between associated SNPs. Our results expand the catalog of genetic loci implicated in psoriasis susceptibility and suggest priority targets for study in other auto-immune disorders.