Contact Sensitization to Hair Care Allergens in Scalp Seborrheic Dermatitis: Associations with Disease Severity and Microbiota Profiles

The study examined the relationship between contact sensitization to hair care allergens and scalp microbiota in 63 participants, including 43 with scalp seborrheic dermatitis (SSD). It identified cobalt chloride, cetrimonium bromide, and minoxidil as common sensitizers in SSD patients. Sensitization patterns were linked to clinical characteristics and changes in scalp microbiota, with minoxidil sensitization negatively associated with Malassezia. The study suggests that allergen reactivity in SSD should be considered alongside skin barrier status and microbial balance, emphasizing the importance of barrier repair and microbiome-oriented strategies in managing SSD. Limitations include a small sample size and cross-sectional design.