Resting-State EEG Points to Central Nervous System Involvement in Atopic Dermatitis With Chronic Pruritus
Atopic dermatitis is usually approached as an inflammatory skin disease, but the burden of chronic itch reaches far beyond the epidermis. In this case-control study, resting-state electroencephalography in adults with atopic dermatitis and chronic pruritus revealed measurable differences in brain activity, adding weight to the idea that persistent itch is processed through central neurophysiological pathways as well as peripheral skin inflammation.
Thirty-seven patients with atopic dermatitis and 38 healthy controls underwent eyes-closed resting EEG and clinical assessment. The design was cross-sectional, and the analysis was deliberately broad: frequency features, power spectral density, functional connectivity, and entropy measures were all examined. Investigators also used the Benjamini–Hochberg false discovery rate procedure, which matters here because EEG studies often generate multiple comparisons across bands and regions. A signal that survives correction carries more clinical and statistical credibility than one that appears only once in an exploratory pass.
Reduced Global EEG Power Across Theta, Alpha, and Beta Bands
The clearest finding was a reduction in global EEG power in the theta, alpha, and beta bands, with all of those results surviving false discovery rate correction. Regional analysis showed the same pattern taking shape more narrowly: power fell in the central region for theta, alpha, and beta bands, and in the occipital region for the beta band. In practical neurophysiologic terms, reduced resting power can reflect altered cortical activation patterns, and in a symptom such as chronic itch, that raises the possibility of persistent sensory processing changes rather than a purely cutaneous complaint.
One sentence captures the signal plainly: resting cortical rhythms were measurably altered in patients with chronic pruritus.
The study also found nominally significant differences in right-hemispheric peak and mean frequencies across the delta and low-frequency beta bands, but those differences did not survive correction for multiple testing. That detail is important because it separates exploratory signals from more stable findings. The broader message comes from the power spectrum, where the reduction in theta, alpha, and beta activity suggests a shift in resting brain dynamics that may accompany the constant sensory load of itch.
Anxiety Symptoms Tracked With a Right-Hemispheric Delta Signal
The most clinically interesting correlation involved right-hemispheric delta peak frequency and anxiety symptoms in patients with atopic dermatitis. The association was positive, with a Spearman correlation coefficient of 0.511 and an FDR-adjusted P value of 0.029. No significant correlations emerged between EEG power measures and clinical symptoms, so this was not a sweeping symptom-imaging alignment. Still, the anxiety link is biologically plausible. Chronic itch can intensify arousal, sleep disruption, and attentional capture, and those pressures may alter slow-wave activity in a way that is detectable at rest.
The association does not prove causality, and the study was not designed to determine whether anxiety drives the EEG pattern, whether the EEG pattern reflects anxiety, or whether both arise from the same chronic itch burden. Even so, the finding is difficult to dismiss. A regional delta-frequency change tied to anxiety suggests that the neurophysiology of itch in atopic dermatitis may overlap with affective circuitry, not just somatosensory processing.
No Difference in Connectivity or Entropy Despite Clear Power Changes
Functional connectivity and multivariate entropy did not differ significantly between groups. In a field where more complex network metrics are often expected to deliver the most novel signal, that absence is informative. The study’s strongest results came from conventional spectral power measures rather than network-based statistics or entropy calculations. This may mean that resting EEG power is more sensitive than higher-order complexity metrics in this specific clinical setting, or simply that the sample size was not large enough to detect subtler network-level disruption.
The absence of connectivity and entropy changes also prevents overreading the data. The patients with atopic dermatitis and chronic pruritus did not present with a generalized collapse of EEG organization; instead, the abnormality was more focused, centered on reduced power in specific bands and regions. For clinicians, that pattern supports the notion of a measurable central signature without claiming a wholesale brain-network disorder.
Biomarker Potential Remains Preliminary but Clinically Relevant
The investigators framed resting EEG measures as candidate biomarkers, and the data support that cautious language. Biomarkers in chronic itch would be useful if they helped stratify symptom burden, identify patients with greater central sensitization, or eventually track response to therapy. This study does not establish any of those uses, but it does identify measurable neurophysiologic abnormalities in a well-defined cohort of patients with chronic pruritus associated with atopic dermatitis.
The trial registration number, ChiCTR2400093716, adds transparency to the study’s conduct, and the ethics approval and informed consent process were clearly documented. Funding came from provincial and municipal Chinese science and traditional medicine agencies. No competing interests were declared.
What remains unresolved is whether these EEG features are specific to atopic dermatitis with chronic pruritus, whether they track itch severity over time, and whether treatment that reduces itching also normalizes the EEG signature. The present dataset does not answer those questions. It does, however, show that chronic itch in atopic dermatitis is not confined to the skin surface; it leaves a detectable imprint on resting brain activity.