Seborrheic Dermatitis: From Microbiome and Skin Barrier Involvement to Emerging Approaches in Dermocosmetic Treatment

Seborrheic dermatitis (SD) is a chronic inflammatory skin disease that primarily affects sebaceous-rich areas such as the scalp, face, and upper trunk. While the precise etiology remains multifactorial, the role of the skin microbiome, particularly the proliferation of Malassezia species, and alterations in the skin barrier function are critical in its pathogenesis. Disruption of the skin barrier, characterized by increased transepidermal water loss (TEWL) and reduced production of epidermal lipids, creates a favorable environment for microbial overgrowth and inflammation. Recent insights highlight the interplay between the impaired barrier function, immune responses, and the skin microbiome in perpetuating the disease. Additionally, novel dermocosmetic approaches are emerging that target these underlying mechanisms, offering promising therapeutic avenues. This review provides a comprehensive overview of the involvement of skin microbiome and barrier dysfunction in seborrheic dermatitis and discusses the potential of advanced dermocosmetic treatments aimed at restoring skin homeostasis and preventing disease recurrence.