Changes in transepidermal water loss and cutaneous blood flow during the menstrual cycle

This study quantified irritant susceptibility and blood vessel reactivity in normal women over the course of the menstrual cycle. Such alterations were studied by observing vasodilation from topical application of methyl nicotinate (MN) on the following days of the menstrual cycle: (i) the day of putative maximal estrogen secretion; (ii) the day of maximal progesterone secretion; (iii) the day of minimal estrogen/progesterone secretion. These responses were evidenced by changes in the following dose response characteristics: the initial response (IR), the peak response (PR) and the area under the curve (AUC). Baseline laser Doppler velocimetry (LDV) blood flow values and transepidermal water loss (TEWL) values on normal skin were also obtained. No significant differences existed for any of the dose-response characteristics (IR, PR, AUC) when the values for the 3 testing days were compared to one another. Significant differences did exist for baseline TEWL values when comparing the day of maximal estrogen secretion to the day of minimal estrogen/progesterone secretion. TEWL was higher on the day of minimal estrogen/progesterone secretion as compared to the day of maximal estrogen secretion on both back (p = 0.037) and forearm (p = 0.021) sites, suggesting that the skin barrier function is less complete on the days just prior to the onset of the menses as compared to the days just prior to ovulation. Significant differences in baseline blood flow also existed for the day of maximal estrogen secretion as compared to the day of maximal progesterone secretion, with higher baseline blood flow recorded on the day of maximal progesterone secretion on both the back (p = 0.021) and forearm (p = 0.009) sites.