Atopic dermatitis: pathogenesis, immunology, microbiome, and salivary biomarkers.

Atopic dermatitis is a chronic inflammatory skin disease influenced by genetic predisposition, immune dysregulation, and environmental factors, as well as skin and gut microbiota. This review summarises the key mechanisms involved in this disease development, including disturbances in innate and adaptive immune responses, ethnic differences in immune pathways, and the contribution of microbial imbalance to skin barrier dysfunction. Special attention is given to salivary biomarkers-such as cortisol, melatonin, alpha-amylase, chromogranin A, C-reactive protein, and immunoglobulin A-which offer a non-invasive method for monitoring stress, sleep quality, and disease severity in patients with atopic dermatitis. Understanding the complexity of these factors may support earlier diagnosis and different treatment strategies and improve long-term disease management in a better way.