Effect of the menstrual cycle phase on foot skin temperature during menthol application in young women

According to the literature, the arteriovenous anastomoses in the peripheral parts (ex. hands and feet) respond thermal stimulation susceptibly. Thus, the feet are sensitive to cold stimulation. The aim of the present study was to investigate the effect of menstrual cycle on skin temperature (T_sk) of the foot during menthol application in young women. T_sk and partial cutaneous blood flow in the foot, tympanic temperature, blood pressure, heart rate, thermal sensation and pleasantness during the preovulatory (P), luteal (L), and menstrual (M) phases during menthol application in young women using thermography, laser Doppler flowmetry, a digital blood pressure monitor, and VAS scale were examined at 25 °C. After application of the 0.5% menthol solution to the right foot, the measurements were continued for 20 min. The T_sk of the second and third right toes in the P phase were lower than that in the L phase. The T_sk of the little right toe in the P phase was lower than that in the L and M phases. No significant differences were observed in the T_sk of the dorsum of right foot, cutaneous Laser-Doppler flow in the right great toe, tympanic temperature, blood pressure, heart rate, thermal sensation and pleasantness among the phases. The menstrual cycle phase did not affect T_sk in the dorsum of the foot, but it affected T_sk in some toes during menthol application.