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Sunday, February 12, 2012
Intrinsic Versus Extrinsic Atopic Dermatitis
Over the past few decades, researchers and clinicians have discovered that there are two forms of AD: intrinsic (nonallergic) and extrinsic
(allergic). Although the two forms are clinically indistinguishable
based on the findings of the physical examination, there are numerous
differences in other aspects (see Table 1 ). Extrinsic AD composes 70%
to 85% of atopic dermatitis, while intrinsic atopic dermatitis makes up
the remaining 15% to 30%. Extrinsic AD is associated with high serum IgE
levels, exhibits allergen-specific IgE to aeroallergens and foods,
positive skin prick reactions, and has a cytokine profile of high IL-4
and IL-13 levels (Bardana, 2004). IL-4, IL-5, and IL-13 cytokines play a
role in the Th2 response which is seen in the early stages of AD.
Chronic atopic dermatitis lesions principally have a Th1 response with
the cytokines IL-12 and interferon-playing a dominant role
(Schmid-Grendelmeier, Simon, Simon, Akdis, & Wuthrich, 2001).
Patients with intrinsic AD, by contrast, have normal IgE levels,
negative skin prick reactions, low IL-4 and IL-13 levels, and they do
not have allergen-specific IgE to aeroallergens and foods (Bardana,
2004). The onset of extrinsic AD typically is in early childhood while
patients with intrinsic AD have a later onset. Finally, patients with
intrinsic AD are characterized by an absence of other atopic disease,
asthma, and allergic rhinitis (Schmid-Grendel meier et al., 2001).
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so, food allergic is ekstrinsik factor...
ReplyDeleteyes you true..
ReplyDeletethe prevalence atopic dermatitis now is increases
ReplyDeleteJust an observation, the article had been more powerful if there is a picture posted depicting the two types of skin disease. The readers here are not all dermatologist that can easily grasp your idea.
ReplyDelete