The following is a summary of “Circadian metabolome of atopic dermatitis,” published in the April 2024 issue of Allergy & Immunology by Ratley, et al.

Atopic dermatitis (AD) is a chronic inflammatory skin condition characterized by dry, itchy skin. Studies have suggested nocturnal increases in itching behavior, indicating a potential role for the circadian rhythm in symptom severity modulation. However, the circadian rhythm of metabolites in the skin and serum of patients with AD remains unexplored. For a study, researchers sought to evaluate the circadian patterns of skin and serum metabolism in patients with AD.

About 12 patients with moderate to severe AD and five healthy volunteers were monitored for 28 hours in a controlled environment. Serum samples were collected every 2 hours, and tape strips were obtained every 4 hours from both lesional and nonlesional skin in patients with AD and matched healthy skin in controls. Untargeted metabolomics analysis was performed to examine circadian peaks of metabolism in patients with AD.

Distinct metabolic profiles were observed between AD and control samples. The greatest differences in serum metabolic pathways, such as arachidonic acid, steroid biosynthesis, and terpenoid backbone biosynthesis, were observed when accounting for the time of collection. A total of 42 circadian peaks were identified in AD or control serum and 17 in the skin. Pathway enrichment and serum-skin metabolite correlation varied throughout the day, with differences most pronounced in the late morning and immediately after sleep onset.

Although limited by a small sample size and observational design, the study suggested that considering the time of sample collection could enhance biomarker detection studies in AD. Furthermore, the findings highlighted potential associations between metabolic changes and nocturnal differences in symptom severity.

Reference: sciencedirect.com/science/article/abs/pii/S0091674924000411