Table 1: Functions of epidermal barrier components and possible protective role in prevention of atopic march.

Barrier componentTypeFunctionPossible role in preventing atopic march

ClaudinTight junction proteinPrevention of water lossPrevention of activation
DesmogleinDesmosome formationPrevention of water lossBlocking allergen penetration
Involucrin/envoplakin/periplakinScaffolding proteinStructural components to create epidermal barrierAllowing appropriate immunoregulatory T-cell environment
Urocanic acidChromophoreHygroscopic acid-base regulator/photoprotectionMaintaining skin barrier function
FilaggrinProteinDecreased permeability of water soluble molecules/epidermal differentiationBlocking allergen penetration
CeramideLipidContribution to skin permeability barrier and epidermal differentiationBlocking mast cell infiltration/expression of TNF
Blocking Mast production of allergic cytokines.
Blocking allergen penetration
Skin protease inhibitors (SPINK)ProteinPrevention of protease alteration in filaggrin and ceramide productionMaintaining skin barrier function