Altered Ceramide Profile of Facial Sensitive Skin: Disordered Intercellular Lipid Structure Is Linked to Skin...

Although sensitive skin (SS) is a syndrome characterized by cutaneous hypersensitivity to environmental factors, its pathophysiology remains elusive.

We aimed to explore the characteristics of ceramides (CERs) and intercellular lipid (ICL) structures of individuals with and without facial SS and their relationship with skin hypersensitivity.

Healthy Japanese females were divided into SS or non-SS groups based on self-perception and lactic acid stinging test (LAST). Stratum corneum (SC) lipids were analyzed using a liquid chromatograph-mass spectrometer, and the orthorhombic-hexagonal lateral packing structure of ICLs was assessed using electron diffraction.

According to the mean LAST score, individuals with SS (n = 48) had mild-to-moderate skin hypersensitivity. SS exhibited not significantly but slightly impaired skin barrier function (p = 0.072) and lower levels of CER[NH], [NP], [EOS], [EOH] (all p < 0.05), and [EOP] (p = 0.073) in the SC compared with non-SS (n = 18). Notably, the CER[NP]/[NS] ratio, a marker of skin barrier function, was positively correlated with the orthorhombic-hexagonal lateral packing ratio of ICLs (p = 0.002), whereas it was negatively correlated with the LAST score (p = 0.015) and the interleukin (IL)-1 receptor antagonist/IL-1α ratio (p = 0.003) in the SC, an indicator of chronic inflammation. Moreover, corneocyte size was reduced in SS (p < 0.001), suggesting inferior SC maturation, and was positively correlated with the CER[NP]/[NS] (p < 0.001) and the orthorhombic-hexagonal ratios (p = 0.011).

Individuals with SS showed an abnormal CER profile, particularly the altered CER[NP]/[NS] ratio, which was in turn associated with disordered ICL structure and skin hypersensitivity. Abnormal epidermal turnover may be an underlying mechanism of the abnormalities.