[Pathophysiology of atopic blepharokeratoconjunctivitis].

Atopic dermatitis (AD) is a systemic inflammatory disease, which is characterized by pronounced eczema and pruritus. In addition to the involvement of the entire integument, the periocular lid skin and the surface of the eye are frequently involved. Ocular involvement may occur solely without dermatitis of facial or body skin. Pathophysiologically, besides a dysregulated immune response, genetic changes can occur in various dermal structural proteins which will lead to a disturbed skin barrier. Furthermore, there is a regular colonization with bacterial pathogens and an increased susceptibility for viral skin infections. The lid margin reveals a loss of Meibomian glands whereas the conjunctiva shows reduced goblet cells. Consecutively, eye surface defects and recurrent conjunctival and corneal defects can be found. Increased mechanical manipulation in atopia-associated pruritus is seen as a cause of increased comorbidity with keratoconus. In addition, individual cases are reported of various malignomas of the eye surface, which are present in patients with AD. Understanding of the pathophysiological connections is essential for the correct diagnosis and therapy of this clinically very complex disease picture.