What is Atopic Dermatitis?

1.a The epidermis in atopic patients

• Deficit in filaggrin :

  protein involved in cohesion between epidermal cells, among its other roles

 

                  • Sometimes genetic (approximately 27% of AD)

                  • Sometimes secondary to inflammation

 

• Excess proteases, enzymes that destroy proteins

 

• Abnormal constitution of cellular cement (ceramides, lipids, etc.)

  that contribute to barrier function

 

• All this leads to increased epidermal permeability:

 

                 • Dry skin (increase in TEWL)

                 • Skin permeable to allergens, infections and microbes