312 JOURNAL OF COSMETIC SCIENCE another study, the quantity of skin microflora was correlated with hormonal changes, and in a third study UV sensitivity was observed. MATERIALS AND METHODS SUBJECTS Females of ages 21-48, with no evidence of acute or chronic disease, including derma­ tological or ophthalmologic problems, were enrolled in the study. In order to qualify, the women had to be in a spontaneous ovulatory menstrual cycle. The subjects were not on any hormonal therapy or infertility treatment and had not taken any oral contraceptives for six months prior to the study. The facial skin had to be free of warts, nevi, moles, sunburn, suntan, scars, and active dermal lesions. On the day of the study, the subjects were instructed to refrain from using any lotions, creams, or other products on the face. Subjects were allowed to equilibrate for at least 30 minutes prior to testing in a controlled environment of 68 ° -70°F and 25% relative humidity. HORMONAL CYCLICITY Twenty-six female participants, ages 21-48, participated in the study. Blood was drawn from the subjects once a week at the same hour of the day by a trained technician following the standard operating procedures for phlebotomy at the clinical testing laboratory. The blood was centrifuged ( 100 rpm for 15 min) to pellet the blood cells and collect the serum. The serum was kept frozen until analyzed. Progesterone and estradiol were assayed from serum, employing a competitive immu­ noassay using direct chemiluminescence technology. Progesterone in the patient sample binds to an acridium ester-labeled mouse monoclonal anti-progesterone antibody. Un­ bound antibody binds to a progesterone derivative, covalently coupled to paramagnetic particles in the solid phase. Relative light units (RLU) detected by the system determine the quantity of progesterone. Estradiol in the patient sample competes with acridium ester-labeled estradiole in the reagent for a limited amount of rabbit anti-estradiol antibody in the antibody reagent. Rabbit anti-estradiole is captured by mouse anti-rabbit IgG, which is coupled to para­ magnetic particles in the solid phase. RLU detected by the system determine the quan­ tity of estradiol (9). EFFECTS OF SYSTEMIC HORMONAL FLUCTUATION ON SKIN The same participants as in the previous study used a simple TEA stearate-based lotion two weeks prior to commencement of the study and for the first month of the study. The subjects applied the assigned test materials on the full face twice a day and were instructed not to change their daily cleansing regimen and makeup for the course of the study. The subjects reported to the clinical testing facility once a week at the same hour of the

HORMONAL CHANGES AND SKIN 313 day, for a month. Data was organized according to the subject's time of the menstrual cycle and labeled as the day of the month relative to the onset of menstruation, which was day 1. The following measurements were obtained every week for four weeks. Barrier functions and repair. Transepidermal water loss was used as the parameter for barrier integrity (10-12). The test sites were the right and left facial cheek areas. A sticky tape (Tesa Tuck, Tape Systems, Charlotte, NC) was used to cover the test area and, after a firm stroke in both directions, the tape was peeled off (12) three strippings were obtained. Transepidermal water loss (TEWL) measurements were recorded using an EP-1 evaporimeter (Servomed, Sweden) at three sites within the stripped area, pre- and post-stripping. The skin was stripped in increments of three, followed by TEWL mea­ surements, until a TEWL of 18 g/m2/hr was reached. Damage to the skin barrier is described in terms of the increase in the rate of water loss. The exact number of strippings required to damage the skin barrier (TEWL = 18 g/m2/hr or more) was calculated by plotting TEWL vs the number of strippings and interpolations. Lactic acid sting. As per the protocol of Frosch and Kligman (13), a 10% solution of lactic acid (98% purity, Sigma, San Diego, CA), prepared in phosphate buffer saline, was used for this study. Lactic acid was applied on the nasolabial fold of one side of the face, and saline was applied to the other side. Any adverse reaction (itching, burning, stinging) reported by the subjects was recorded after 2.5 minutes and 5 minutes. The stinging intensity was graded by the subjects as mild, moderate, or severe (scored as 1, 2 or 3, respectively). The sums of the scores at both time points were calculated as the cumu­ lative intensity of the stinging effect. Moisturization. Skin moisturization was measured via the Nova Meter DPM 9003 (NOVA Technology Corporation, Portsmouth, NH) following the protocols of Tagami (14) and Barel and Clarys (15). Surface electrical capacitance provides a representation of skin surface hydration that is inversely proportional to electrical impedance. The Nova measures an output proportional to the skin's electrical capacitance in the Mhz frequency range. Data acquisition is software-controlled. The higher the skin water content, the higher the output (in arbitary units), and hence, the more moisturized is the skin. Skin surface lipids. Skin surface lipids were evaluated using a sebumeter SM8 l 0 (Courage and Khazaka, Cologne, Germany) as described by Cunliffe et al. (16). Three-hour accu­ mulation of skin surface lipids was measured. Briefly, three hours after washing the forehead with a mild liquid soap, a translucent plastic strip 0.1-mm thick and with an area of 64 mm2 is applied on the skin and held at constant pressure for a defined time interval, during which sebum absorbs to the strip. The sebumeter measures the increase in the transparency of the strip when it becomes soaked with sebum. The strip is backed by a mirror, which presses it against the skin with a force of l0N by means of a spring. The instrument contains a timing device, which allows for a 30-second measurement. The transparency of the strip is evaluated by means of a microprocessor and is read off a digital instrument directly as gram of sebum per square centimeter. Skin microflora (17-18). Twenty-eight female participants, ages 21-48, were selected for the study based on the criteria described above. The mornings of each visit the subjects washed their face thoroughly with a given mild (anionic, sodium laureth sulfate base) liquid soap and warm water. The subjects were instructed not to wash or even touch their faces for the next three hours. Three-hour bacterial growth was obtained in a saline wash collected from the forehead using a cup-scrub method. A glass cup was held