Interlamellar lipid differences between normal and psoriatic stratum corneum.

Intercellular lipids of the stratum corneum are involved in permeability barrier integrity and function. In psoriasis, desquamation and permeability barrier homeostasis are modified; these observations are consistent with an alteration in stratum corneum lipid production. Therefore, in the present study, we determined and compared the total content of the three main intercellular lipids in psoriatic scales and normal human stratum corneum. Our results showed that the relative free fatty acid content decreased remarkably (46%) in psoriatic scales, compared with normal human stratum corneum. This decrease may reflect a general state of emergency of keratinocytes, in which free fatty acids can be employed.