How is pathogenesis of atopic dermatitis?

Multifactorial (genetics, skin barrier dysfunction, impaired immune response and environment) may be filaggrin deficiency, T helper produces cytokines (IL4/ IL13 by Th2) that initiate positive feedback loop, reduce KC differentiation and increase epidermal hyperplasia by reducing expression of epidermal structural proteins and may cause itchy lesions Hyperplasia causes lichenification, decreased structural proteins cause pruritis and allergen entry.