Metabolomics in Scalp Seborrheic Dermatitis Evidenced Key Changes in Inflammatory Markers Following a 10-Week Scalp Care Scheme with an Anti-dandruff Shampoo.

INTRODUCTION

Mild-to-moderate scalp seborrheic dermatitis (SD) is commonly managed by using anti-SD shampoos containing antifungal, anti-inflammatory, and keratolytic agents. A newly formulated anti-SD shampoo containing the patented combination of two antifungal actives has shown good clinical efficacy and tolerability in a previous two-phase randomized controlled trial.

METHODS

A specific analysis of scalp SD-associated metabolome was conducted to identify molecular markers involved in SD symptoms, and examine the impact of the anti-SD shampoo on these compounds. The intervention scheme involved a 2-week phase of intensive product use (three times a week), followed by an 8-week parallel-group maintenance phase consisting of the test group using the study shampoo once a week, and the control group using a neutral shampoo.

RESULTS

Following the intensive phase of the intervention, a significant decrease in the levels of SD markers (cathepsin S, interleukin-8, and histamine), inflammatory lipids (arachidonic acid, linoleic acid, and oxylipins), and metabolites involved in tryptophan metabolism (indolacetate and indolelactate) was observed. These changes were sustained during the maintenance phase in the test group only, supporting the clinical efficacy of the anti-SD shampoo. The integrated analysis of metabolome and fungal microbiome data suggested a positive correlation between the level of Malassezia fungi and that of two oxylipins (9,10,13-triHOME and 9-HODE), highlighting the pivotal role of these lipolytic fungi in SD conditions, and the involvement of newly identified proinflammatory lipid mediators. These oxylipins could be used as novel targets for developing alternative anti-SD strategies.

CONCLUSION

This approach allowed us to better characterize specific interactions within the scalp ecosystem providing deeper insights and unravelling new therapeutic pathways in SD like pro-inflammatory oxylipins.

GOV IDENTIFIER: NCT06578962 (retrospectively registered on August 28, 2024).