Examining the Link Between AD Severity, Learning Disorders Among Children

Results of a cross-sectional study suggest worse atopic dermatitis (AD) severity is associated with greater odds of reported learning disability (LD), and that this relationship is independent of socioeconomic status, age of AD onset, and other related disorders. The findings were published JAMA Dermatology.

Previous research has shown AD in children is associated with disruptions in sleep, attention, and memory, while US population-based data show children with AD demonstrate a greater prevalence of LD compared with those without it.

To better understand the link between pediatric AD severity and LD, or “disorders that impair areas of learning, such as reading, writing, and mathematics,” researchers analyzed data from the Pediatric Eczema Elective Registry (PEER). PEER is a postmarketing safety study for pimecrolimus, a treatment for AD.

All study participants were between the ages 2 and 17 at registry enrollment and had diagnoses of AD confirmed by physicians. Patients were followed-up with for 10 years and all data included were deidentified. Any individual who reported a diagnosis of autism was excluded from analyses as clinical diagnoses of LD and autism are considered mutually exclusive.

“In addition to self-reporting their AD severity in the preceding 6-month period, participants completed the Patient-Oriented Eczema Measure (POEM), a validated core outcome instrument for measuring patient-reported symptoms of AD in the past week,” at the 10-year follow-up, the researchers wrote.

Of the 2074 participants in the study, the majority (53.8%) were female. Median age (interquartile range [IQR]) at the time of enrollment was 6 (3.8-9.4), while median age at 10-year follow-up was 16.1 (13.9-19.5). Around 45% of participants reported Black race/ethnicity and around 40% reported White race/ethnicity.

A total of 169 (8.2%) of participants reported a diagnosis of an LD. These children were more likely to have worse AD severity compared with those without an LD, measured by:

• Median (IQR) total POEM score (5 [1-10] vs 2 [0-6]; P < .001)
• POEM severity category (moderate AD: 50 of 168 [29.8%] vs 321 of 1891 [17.0%]; severe to very severe AD: 15 of 168 [8.9%] vs 85 of 1891 [4.5%]; P < .001)
• Self-report (moderate AD: 49 of 168 [29.2%] vs 391 of 1891 [20.7%]; severe AD: 11 of 168 [6.5%] vs 64 of 1891 [3.4%]; P < .001)

Analyses adjusted for sex, age, race/ethnicity, annual household income, age of AD onset , family history of AD, and comorbid conditions showed “participants with mild AD (odds ratio [OR], 1.72; 95% CI, 1.11-2.67), moderate AD (OR, 2.09; 95% CI, 1.32-3.30), and severe to very severe AD (OR, 3.10; 95% CI, 1.55-6.19) on the POEM were all significantly more likely to have reported an LD than those with clear or almost clear skin.”

Asthma, depression, and anxiety were also more common among participants who were diagnosed with an LD.

Overall, more severe AD was associated with up to a 3-fold increase in odds of an LD. Previous research has yielded conflicting results on this association and more studies are needed to clarify both the association of AD with learning and the mechanisms through with it may be mediated.

Authors hypothesized symptoms of AD, including itch and sleep impairment, may make learning more difficult for children. “Neuroinflammatory signaling in the central nervous system is also implicated in normal memory and learning, and one could speculate that shared inflammatory or other pathophysiological pathways may link AD and LD,” they wrote.

More severe AD has also been associated with environmental factors which could contribute to vulnerability of cognitive or learning dysfunction. In addition, attention deficit hyperactivity disorder (ADHD), mood disorders conduct problems and sleep problems “may be factors on the causal pathway and thus may be mediators rather than confounders of the association between AD severity and LD.”

Outcome misclassification was a potential source of bias in the study, and researchers could not examine physicians’ assessments of AD severity or account for other factors associated with LD, marking limitations. As participants were required to have previously used pimecrolimus, findings may not be generalizable to all children with AD; although the treatment is commonly prescribed.

“Given that an LD has potentially lifelong implications for health, educational, and social outcomes, earlier identification (screening) and treatment of at-risk children, particularly those with moderate or severe AD, are thus critical for reducing the detrimental consequences of AD for learning, developing appropriate interventions, and ensuring optimal socioeducational outcomes in this patient population,” researchers concluded.

Reference

Wan J, Mitra N, Hooper SR, Hoffstad OJ, and Margolis DJ. Association of atopic dermatitis severity with learning disability in children. JAMA Dermatol. Published online April 14, 2021. doi:10.1001/jamadermatol.2021.0008