As for the classification of atopic dermatitis (AD), the usual method is to divide it into exogenous AD (extrinsic AD) and endogenous AD (in
As for the classification of atopic dermatitis (AD), the usual method is to divide it into exogenous AD (extrinsic AD) and endogenous AD (intrinsic type). Research shows that these two types of AD have some differences in clinical manifestation, pathogenesis and treatment strategies, so some scholars proposed that endogenous AD is non allergic AD (non-allergic AD) or "non atopic dermatitis" (non-atopic dermatitis), and not the real AD (true AD), should be called. Be like dermatitis (atopiform dermatitis), and the real is mediated by IgE AD to distinguish. This idea has not been widely accepted, because this completely excluded classification may suggest that clinicians are "atopic dermatitis" and atopic dermatitis are two different diseases. In fact, although there are some differences between the two types, but more common than personality, even in the same patient, the clinical manifestations in different periods of dynamic change. For example, some of the early onset of AD patients in the early stage and there is no IgE sensitization, but with the extension of the course can be gradually appeared for a variety of allergens sensitization. Therefore, it is not possible to diagnose AD with a certain stage of IgE mediated sensitization.
In order to reduce the confusion of clinical diagnosis and disease of the same patient were explained, these changes may be attributed to the differences between the types of the three stages in the natural history of AD: the initial stage is the period of infant nonatopic type dermatitis, this time sensitization has not yet occurred; then, affected genetic and environmental factors of 60%-80% patients, the gradual emergence of the antibody IgE for food and / or environmental allergens and sensitization, cause the disease into true AD; finally, scratching causes skin damage cells and release of self antigen induced type IgE autoantibodies in a considerable part of patients in AD. Of course, the evolution of each patient's disease is not the same, the three stages can be successively, at the same time or not completely in a patient.
From: Song Zhiqiang. New progress and new ideas of atopic dermatitis. Journal of Clinical Department of Dermatology, 2010,39 (9): 074-076