Skin Barrier Function and Its Importance at the Start of the Atopic March

Table 1

Functions of epidermal barrier components and possible protective role in prevention of atopic march.

Barrier component	Type	Function	Possible role in preventing atopic march
Claudin	Tight junction protein	Prevention of water loss	Prevention of TH2 activation
Desmoglein	Desmosome formation	Prevention of water loss	Blocking allergen penetration
Involucrin/envoplakin/periplakin	Scaffolding protein	Structural components to create epidermal barrier	Allowing appropriate immunoregulatory T-cell environment
Urocanic acid	Chromophore	Hygroscopic acid-base regulator/photoprotection	Maintaining skin barrier function
Filaggrin	Protein	Decreased permeability of water soluble molecules/epidermal differentiation	Blocking allergen penetration
Ceramide	Lipid	Contribution to skin permeability barrier and epidermal differentiation	Blocking mast cell infiltration/expression of TNF; Blocking Mast production of allergic cytokines.; Blocking allergen penetration
Skin protease inhibitors (SPINK)	Protein	Prevention of protease alteration in filaggrin and ceramide production	Maintaining skin barrier function