[Pathogenesis of atopic dermatitis]

Atopic dermatitis (AD) is a familial inflammatory skin disorder which is characterized by extreme pruritus, the typical morphology and distribution, the chronic or chronically relapsing time course and the personal or family history of atopy (asthma, allergic rhinitis, atopic dermatitis). However, there exists a variety of additional features which are either less specific or relatively rare. Although this disease has been well-known since the beginning of the century, the pathogenesis is not clearly understood at present. This review summarizes the reported deviations of the immune system as well as the alterations of the mediators of inflammation and the abnormalities of cyclic nucleotide regulation. These findings will be correlated with clinical symptoms. In particular the following topics were taken into consideration: association with HLA-antigens, elevation of serum IgE and generation of IgE immune complexes, numerical and functional deficiencies of T-suppressor cells, involvement of granulocytes, alterations of mediators of inflammation and especially the observations on the cyclic adenosine monophosphate (cAMP)-phosphodiesterase. These extremely complex findings based on the interaction between disregulation of the autonomous nervous system and alterations of the immune system may provide a better understanding of the pathogenesis of atopic dermatitis.