The Inflammation–Itch–Neurobehavioral Axis: Exploring the Link Between Pediatric Atopic Dermatitis and ADHD

Atopic dermatitis (AD) and attention-deficit/hyperactivity disorder (ADHD) frequently co-occur in children and adolescents, but the nature of the relationship remains uncertain, according to a narrative review examining the epidemiology, potential mechanisms, and clinical management of the 2 conditions.¹ Although observational studies consistently report an association, genetic studies have not supported a direct causal relationship. The authors propose that chronic inflammation, pruritus, sleep disruption, and neurobehavioral effects may interact through an “inflammation–itch–neurobehavioral axis.”

Disease Severity and Trajectory

AD affects approximately 20% of children globally, while ADHD is characterized by persistent inattention, hyperactivity, and impulsivity. Meta-analyses have estimated that children with AD have approximately 28% to 34% higher odds of ADHD, with stronger associations reported among school-age children.² A global systematic review found that ADHD prevalence among children with AD was 9%. Longitudinal studies have also reported increased subsequent ADHD risk among children with early-onset AD, particularly those with earlier or more severe disease.

Disease severity and course may influence the association. One systematic review found ADHD prevalence of 7% among children with mild AD compared with 15% and 16% among those with moderate and severe disease, respectively. A 2025 trajectory study found that children with early-onset persistent AD had the highest ADHD risk compared with other disease-course patterns.

Sleep disturbance emerged as an important factor. Children with AD commonly experience difficulty initiating or maintaining sleep because of chronic nocturnal pruritus. In 1 analysis, children with severe AD and substantial sleep insufficiency had an odds ratio of 16.83 for ADHD, compared with 1.83 among those with sleep disturbance alone and 1.56 among those with mild to moderate AD. A meta-analysis found that AD patients with sleep disturbances had increased odds of ADHD symptoms or diagnosis. However, the review noted that the quality of evidence supporting this association remains low.

Diagnosed ADHD vs. Transient Neurobehavioral Symptoms

The authors distinguish formally diagnosed ADHD from ADHD symptoms and transient ADHD-like behaviors. Chronic itch, fragmented sleep, and psychosocial stress associated with AD may produce inattention, hyperactivity, and impulsivity that resemble ADHD and may improve when AD is effectively treated. This distinction is clinically important because recent evidence challenges a direct causal relationship. A UK population-based cohort found no significant association between childhood AD and ADHD after adjustment for confounders, while a bidirectional Mendelian randomization analysis found no evidence that genetically determined AD increased ADHD risk or that genetically determined ADHD increased AD risk.

Mechanisms of the Inflammation–Itch–Neurobehavioral Axis

The proposed “inflammation–itch–neurobehavioral axis” incorporates several possible pathways. AD-associated type 2 inflammation may influence neurodevelopment through systemic inflammatory signaling. Chronic pruritus can disrupt sleep and impair attention and behavioral regulation, while persistent itch and stress may affect the hypothalamic-pituitary-adrenal axis and neurotransmitters involved in attention and executive function. Preclinical studies have also identified potential neuroimmune pathways involving sympathetic activation, norepinephrine, basophils, and eosinophils, although direct evidence in children remains limited.

Clinically, the review recommends proactive assessment of ADHD-related symptoms in children with moderate to severe or early-onset AD, particularly those with significant sleep disturbance. Standardized tools such as the Vanderbilt rating scales may help assess symptoms and behavioral problems. Management should prioritize control of skin inflammation and pruritus, along with interventions for sleep disturbance and chronic stress. If ADHD is independently diagnosed and affects daily functioning, treatment should follow established ADHD guidelines.

The review also emphasizes monitoring skin symptoms and sleep when ADHD medications are initiated or adjusted. Methylphenidate has been associated with increased risk of insomnia, while atomoxetine has been associated with cutaneous adverse reactions including rash and pruritus.

Study Limitations and Future Research

The authors acknowledge limitations, including the narrative design, heterogeneity of the available evidence, varying ADHD diagnostic approaches, reliance on observational studies, and limited pediatric evidence for proposed mechanisms. Overall, they conclude that AD and ADHD frequently coexist, but the association may reflect secondary effects of AD rather than a direct causal pathway. Prospective studies are needed to determine whether controlling inflammation, pruritus, sleep, and neuroimmune pathways can improve both dermatologic and neurobehavioral outcomes.

References

1. Zhao Q, Liang Y, Liu Y, et al. Atopic dermatitis and attention-deficit/hyperactivity disorder comorbidity in children and adolescents: Epidemiology, mechanisms, and clinical management. Pediatr Investig. Published online August 28, 2026. doi:10.1002/ped4.70083

2. Cheng Y, Lu JW, Wang JH, Loh CH, Chen TL. Associations of Atopic Dermatitis with Attention Deficit/Hyperactivity Disorder and Autism Spectrum Disorder: A Systematic Review and Meta-Analysis. Dermatology. 2024;240(1):13-25. doi:10.1159/000533366