Atopic Dermatitis - a Twitter summary from the 2012 WSAAI meeting

This summary was compiled from the tweets posted by @MatthewBowdish, an allergist/immunologist, who attended the 2012 Western Society of Allergy, Asthma and Immunology (WSAAI) meeting. The tweets were labeled #WSAAI. The text was edited and modified by me.

Atopic Dermatitis

Dr. Lisa Beck discussed Barrier Dysfunction and Immune Dysregulation in Atopic Dermatitis:

14-20% of children have atopic dermatitis at some point in their development. 20-30% atopic dermatitis cases begin during adulthood.

Atopic dermatitis (AD) is likely a result of:

1. Adaptive Immune Defects
2. Barrier Defects
3. Innate Immune Defects

Genes in AD

Filaggrin has been validated as an AD candidate gene in 36 studies - other gene defects are much less common (e.g., IL4, IL4RA, SPINK5 only x5).

Complete absence of filaggrin leads to increased epicutaneous sensitization but with mixed Th2/Th17/Th1 response. You only get filaggrin expression in areas where you have a stratum corneum, so fillagrin is not involved in intestinal permeability.

Filaggrin mutations increase the risk for persistent dry skin and eczema independent of sensitization (JACI, 2012).

You have to disrupt tight junctions to initiate an innate immune response - TLR2 expression is below tight junctions. When you scratch in atopic dermatitis, you disrupt both stratum corneum AND tight junctions.

Markers of Th2 immunity (eosinophilia, total serum IgE and TARC) are betters predictors of disease severity in AD than asthma.

Allergens in AD

Allergens in atopic dermatitis include foods, aeroallergens, self-antigens (epithelial proteins) and microbial antigens.

S. aureus (enterotoxins), M sympodialis, and allergens are trigger factors of atopic dermatitis - they stimulate dendritic cells (JACI, 2012). The most common microbial antigens in AD are Dermatophytes, Pityrosporum and S. aureus.

Here is a suggested approach to the management of atopic dermatitis:



Figures:



This summary was compiled from some of the tweets posted by @MatthewBowdish . The tweets were labeled #WSAAI and they reached more than 3,000 people. I would strongly encourage you to post updates on Twitter from the CME conferences that you are planning to attend in the future. Here is how to do it: Twitter for Physicians: How to use Twitter to keep track of the latest news and scientific meetings, and share information with colleagues and patients.

Disclaimer: The text was edited, modified, and added to by me.