Sebum measurements for rapid identification of hyperandrogenism due to an ovarian Leydig cell tumor

Moisturizing and antisebum effect of cosmetic application on facial skin

BACKGROUND

Water content of the stratum corneum and skin surface lipids are important factors in the appearance and function of skin. High water content and low sebum secretion are considered main features of fair skin. Aim This paper aims to study the change of skin physiological parameters after cosmetic application.

METHODS

The skin water content, transepidermal water loss, and skin sebum secretion on different regions of the facial skin before and after the cosmetic application were measured using Corneometer, Tewameter, and Sebumeter, respectively.

RESULTS

The cosmetics kept higher water content and lower transepidermal water loss, at the same time lower sebum secretion 4 and 8 h after the cosmetic application, compared with those before it. The situation was maintained in the following 3-week continuous use of the cosmetics.

CONCLUSION

The cosmetic application on human facial skin could provide some moisturizing effect and at the same time some antisebum effect according to different regions on facial skin, which favored the maintenance of good skin physiological function after applying skin care products.

Evaluation of facial skin type by sebum secretion: discrepancies between subjective descriptions and sebum secretion

BACKGROUND/AIMS

Facial skin is usually classified as dry, normal, and oily in the cosmetics field. However, there is no standard objective method for classifying facial skin.

METHODS

We measured sebum excretion with Sebumeter at four sites on the face. Based on the amount of sebum secretion, we reclassified skin type according to the guidelines provided by the manufacturer. The mean of sebum excretion (mean facial sebum excretion; MFSE) was also calculated.

RESULTS

People secrete varying amounts of sebum at different skin sites. Reclassification of skin type based on sebum secretion revealed that most participants underestimated the amount of facial sebum excretion. When sebum secretion amounts were compared, a statistically significant difference was apparent between the oily and dry skin types. However, there were no statistical differences between oily and normal, and normal and dry skin.

CONCLUSION

We showed that subjective skin type does not match the amount of sebum secreted. Thus, this simple and subjective classification is of very limited use and it should be re-evaluated by using an objective and standardized measuring tool.

Is seborrhea a sign of autonomic impairment in Parkinson's disease?

An increase of sebum excretion rate (SER) is frequently observed in patients suffering from Parkinson's disease (PD). Some authors attribute it to the hyperactivity of the parasympathetic system, while others consider the possible action of androgens or of MSH-hormone. The aim of our study was to verify and quantify SER in 70 parkinsonian patients and compare it with SER in 60 normal subjects. We found higher values of SER in male subjects, both in normal and in parkinsonian patients. The highest rate of excretion was observed in parkinsonian males, in agreement with the possible main role of androgens or testosterone in sebum excretion, while the phenomenon did not appear to be related to abnormalities of the autonomic nervous system. The association of PD and sex hormones might therefore be crucial for the developing of seborrhea.

Quantitative evaluation of skin surface lipids

More than 50 years of noninvasive studies of epidermal and sebaceous lipids has revealed a vast amount of information concerning secretion and regulation of SSLs. The first techniques developed (solvent extraction and cigarette paper) required very long experimental procedures to obtain valuable parameters; however, a great part of the knowledge on SSL production and regulation was obtained by these pioneers. Because of the difficulties encountered in these multistep procedures, applicability was restricted to a limited number of research centers. The sampling procedures in the newly developed techniques are significantly reduced and are followed by a fast and accurate evaluation. Moreover, the new sampling procedures permit us to study other aspects of sebum secretion, as demonstrated with the Sebutape method. When using photometric techniques an estimate of the SSL can be obtained within minutes (casual level measurements). After such a screening procedure, more standardized parameters can be accurately determined. Whatever the parameter under investigation, strictly controlled experimental procedures are required. Control of temperature and relative humidity of the experimental room, of the acclimatization periods, and of the volunteers during the collection periods is of capital importance. The studies discussed in this article clearly demonstrate the applicability of the new techniques not only for research and cosmetic purposes but also for clinical use.

The casual level of meibomian lipids in humans

Using a modified skin surface lipid measuring instrument, the Meibometer, the amounts of meibomian lipid on the lid margins (the casual levels) of 421 subjects aged 1 to 94 years were measured. The lowest levels were found in children younger than 14 years (means +/- S.E.: males = 1.48 +/- 0.17, females = 1.53 +/- 0.17 micrograms lipid/mm2 lid margin surface) and rose with age, the highest levels being found in males aged 60-69 years (mean +/- S.E. = 3.26 +/- 0.18 micrograms lipid/mm2 lid margin surface). Male levels were higher than females in the 20-29 years age group but male and female levels became indistinguishable above the age of 50. These age- and sex-related changes differed markedly from those seen in skin surface lipid levels. The age-related changes in the casual levels of lid lipids remain unexplained although an endocrinological mechanism modified by morphological factors is considered.