Seasonal changes in epidermal ceramides are linked to impaired barrier function in acne patients.

Acne skin demonstrates increased transepidermal water loss (TEWL) compared with healthy skin, which may be due, in part, to altered ceramide (CER) levels. We analysed ceramides in the stratum corneum of healthy and acne skin, and studied seasonal variation over the course of a year. Using ultraperformance liquid chromatography with electrospray ionisation and tandem mass spectrometry (UPLC/ESI-MS/MS), we identified 283 ceramides. Acne-affected skin demonstrated overall lower levels of ceramides, with notable reductions in CER[NH] and CER[AH] ceramides, as well as the acylceramides CER[EOS] and CER[EOH]; these differences were more apparent in the winter months. Lower ceramide levels reflected an increase in TEWL in acne, compared with healthy skin, which partly resolves in the summer. Individual ceramide species with 18-carbon 6-hydroxysphingosine (H) bases (including CER[N(24)H(18)], CER[N(26)H(18)], CER[A(24)H(18)], CER[A(26)H(18)]) were significantly reduced in acne skin, suggesting that CER[NH] and CER[AH] species may be particularly important in a healthy skin barrier.

Evaluation of Seasonal Changes in Facial Skin With and Without Acne.

The objective of this study was to compare facial skin of adolescent males with (acne) and without acne (non-acne) over the course of 1 year. At study entry, presence of acne was determined by clinical image analysis (acne n=7, non-acne n=10). Monthly evaluations of skin condition were made using standard and fluorescent imaging, fluorescence spectroscopic analysis, sebum analysis, skin high frequency conductivity (moisture content), transepidermal water loss (TEWL), and sampling of skin bacteria (aerobic and anaerobic). Data were evaluated seasonally. Over the course of the study, subjects in the acne and non-acne groups had no significant increase in their clinical acne score. Sebum production was significantly greater in subjects with acne than in those without for each season examined (P<0.019) and was lowest in the winter and highest in the fall. TEWL was higher in those with acne than without acne across all seasons (P=0.001). Skin moisture in both groups was increased during summer and fall compared with winter (P≤0.016 for both seasons). Subjects with acne had a higher recovery of both aerobic and anaerobic bacteria compared with subjects without acne (P≤0.015). Analysis of cheek skin in the nasal area revealed significantly higher fluorescence (500-800 nm) in image-based and spectroscopic analysis from subjects with acne, suggesting the greater presence of the bacterial metabolite porphyrin in those with acne. In these cohorts of adolescent males, significant differences in sebum production, skin barrier function, moisture content, and microbial load (anaerobic and aerobic) were noted between those with and without acne. Evidence for seasonality was observed, with lower lipid production and reduced barrier function during the winter. More studies to quantify differences in skin lipid components and bacterial species among these cohorts are planned.