Sebum excretion in Parkinsonism

The sebum excretion rate on each side of the forehead was measured in nineteen patients with Parkinsonism, and related to the severity of the neurological disorder on each side of the body. The absence of a significant correlation between sebum excretion and the severity of Parkinsonism on the two sides suggests that the seborrhoea of Parkinsonism is unlikely to be due to a peripheral neurological effect.     

Sebum excretion rate, surface lipid composition and constitutional eczema

The sebum excretion rate of subjects with constitutional eczema was no different from that of a matched group of controls. This would suggest that one reason for the reduced incidence of acne amongst atopic subjects is partly determined by the low sebum excretion rate.     

Sebum excretion in hypopituitarism

The sebum excretion rate (SER) was measured in thirty-one patients with hypopituitarism of diverse aetiology, and the mean SER was found to be greatly decreased compared with control patients of the same age. The decrease was apparent even in patients who were receiving replacement therapy with hydrocortisone, thyroxine and testosterone. These findings confirm the importance of the pituitary gland in maintaining sebaceous activity in man, and the nature of the pituitary sebotrophic factor is discussed.     

Sebum excretion rates in mothers and neonates

As neonates have a high sebum production compared with 6-month-old babies, we wished to investigate the relationship of sebum production in mother and neonate. The sebum excretion rate (SER) was therefore measured in 10 mothers prenatally, and in each mother and baby as soon after birth as possible, and again 5-12 weeks postnatally. There was a significant correlation between the maternal and neonatal SER perinatally. The perinatal SER in the babies was markedly higher than the postnatal sample. These observations suggest an important role for the maternal hormonal environment on the infant sebaceous glands. There is animal evidence which suggests that the endocrine environment of the neonate influences the sebaceous gland development in puberty, but it is not known whether babies with a high SER are more prone to seborrhoea and acne in later life.     

Sebum suppression by benzoylperoxide

Sebum excretion rate (SER) was determined by thin-layer chromatography and based on densitometric data in 9 male and 5 female patients suffering from acne during treatment with 10% benzoylperoxide (BPO). BPO was applied to the forehead (treatment area), whereas gel only was applied to the chest (control area) for 6 weeks. SER decreased in 10/14 subjects, no change was found in 1 subject and 3 patients exhibited an increase in SER. Suppression varied between 12 and 86%. Concomitant SER reduction in control and treatment areas was noted in 6 patients. When treatment and control areas of individual patients were considered for data evaluation, SER decrease was noted in only 4 out of 14 subjects. Similar results were obtained when free fatty acids, triglycerides and squalene data were analyzed. Combined, these data suggest that BPO may affect SER in some patients. The present experiments indicate the importance of adequate controls in such studies.     

The sebum excretion rate in rosacea

The sebum excretion rate (SER) was measured in fifty-five patients with rosacea and 126 control subjects. The mean SER in the patients with rosacea was not increased, nor was there any correlation between SER and severity of rosacea. Our data suggest that seborrhoea plays no part in the pathogenesis of rosacea.     

Absence of Minocycline in Sebum?

The authors studied the bioavailability of minocycline in sebum and serum. Blood and sebum samples were collected weekly for 6 weeks from ten healthy volunteers taking 200 mg of minocycline every day for 4 weeks. Sebum was collected by direct extraction with petroleum ether from the forehead. After evaporation, sebum was weighed on a scale accurate to 10 micrograms. Determination of minocycline in serum and sebum was performed using a high performance liquid chromatography technique (HPLC), with a better detection limit at 352 nm than at 400 nm (20 ng/ml and 0.324 microgram/ml respectively). Our results contrast with other studies since no minocycline was detected in the sebum samples of treated subjects and microbiological assays of minocycline in sebum were also negative. In our opinion, the current hypothesis claiming that the effectiveness of minocycline in the treatment of acne vulgaris is based on sebaceous secretion should be reconsidered.     

Sebum, cosmetics, and skin care

Recent contributions to the understanding of the physiology and biochemistry of sebum production and of the lipids on the skin surface are leading to the development of effective strategies to regulate excessive sebum production and its consequences through the use of cosmetics and skin care products.