Early insights from 'Mind & Skin': altered functional connectivity is associated with decreased cognitive performance in atopic dermatitis

Atopic dermatitis (AD) is a T helper 2-mediated inflammatory condition, resulting in erythematous and pruritic skin. Patients with AD often have chronic itching, leading to subsequent scratching, which further damages the skin and exacerbates cutaneous inflammation. Patients with AD often experience severe itching–scratching behaviour at night, leading to poor sleep quality. Chronic sleep disturbances during early childhood may alter brain development and neural connectivity, contributing to the increased risk of neuropsychological problems in patients with AD. In Mind & Skin, we aim to understand how inflammation and itch experienced by patients with AD can affect sleep, functional connectivity and cognitive function. Adolescent patients with AD were recruited from paediatric allergy and dermatology clinics, whereas healthy controls were recruited from patients’ healthy siblings or through internal newsletters. Resting-state functional magnetic resonance imaging (fMRI) scans were acquired from the participants. The participants also completed a series of cognitive tasks using the Maudsley Attention and Response Suppression task battery to assess their attention, motor and cognitive inhibition, and time perception. Eighteen adolescent patients with AD with a range of disease severities (median age 15 years, range 12–18) and nine healthy controls (median age 15 years, range 12–16) were recruited for the study. The patients with AD had a median Eczema Area and Severity Index score of 4.45 (range 0.8–30.9). Sixteen resting-state networks were identified from fMRI analysis. The patients with AD, relative to healthy controls, had significant increases in functional connectivity within the somatosensory motor network, likely associated with chronic itching–scratching behaviours. The patients with AD exhibited reduced functional connectivity between the visual cortex and the temporoparietal network compared with healthy controls. The cohort with AD also showed decreased performance in the Simon (cognitive interference inhibition) and time discrimination tasks compared with healthy controls. The temporoparietal junction (TPJ) has been suggested to be a multisensory integration hub and is crucial for visual–spatial attention to external stimuli. Enhanced somatosensory connectivity in AD may disrupt TPJ–visual connectivity, potentially affecting selective visual–spatial attention and contributing to reduced ability in the Simon task. Our preliminary findings provide insights into the neurocognitive effects of the chronic itch–scratch behaviours associated with AD and how they may be associated with changes in brain network connectivity. These insights highlight the need for a multidisciplinary approach to address the dermatological and neurodevelopmental impacts of AD, with future studies aimed at identifying targeted interventions that mitigate these specific cognitive difficulties and improve quality of life.