The assessment of skin sebum and moisture content of infants with atopic dermatitis

Background/aim: Atopic dermatitis (AD) is a chronic, inflammatory skin disorder characterized by dry skin, pruritus and eczematous lesions. The aim of this study is to evaluate the skin moisture and sebum content of the infants with AD and its relationship between the disease severity. Materials and methods: For this cross-sectional and case-control study we included 49 infants with AD aged between 2 and 24 months and 34 healthy infants with the same age and sex as a control group. Skin moisture and sebum content were measured by the bio- impedance method and recorded. Skin prick tests, total IgE levels and food-specific (milk, egg) IgE levels were performed. Results: There was a significant difference between the groups in terms of mean skin moisture and sebum content percentage (P < 0.001, both). The mean skin moisture and sebum content were correlated with CRP in patients with AD (P < 0.01, r = ­1.00, both), but we did not find any correlation between these parameters with the disease severity. Conclusion: We found that skin moisture and sebum content were low even in unaffected areas in AD. The skin structure of these patients may contribute to the pathogenesis of the disease.

Skin sensitivity evaluation: What could impact the assessment results?

BACKGROUND: For the evaluation results of skin sensitivity, such as clinical parameters, stinging test records and biophysical assessments dates might be impacted by many factors, the influence factors need to be further explored, and the skin sensitivity evaluation process and methodology needed distinction and normalization. In this study, we investigated the changes of sensitive skin indexes and lactic acid stinging test results in different seasons, facial regions, skin photo-type, and living habits. METHODS: Twenty-four healthy subjects had completed this study. Lactic acid stinging test was performed in different seasons. Transepidermal water loss (TEWL), skin hydration, sebum secretion, and pH were measured in an environment-controlled room. Correlations between stinging responses, skin biophysical parameters, and sensitive skin inducements in different seasons were statistically analyzed. RESULTS: Skin TEWL, hydration, sebum secretion, and pH values on different facial parts were various. Two-way correlation analysis between the results of lactic acid stinging test in different seasons and the sensitivity factors showed differences between summer, autumn, and winter. The mean scores of lactic acid stinging test increased in autumn. Linear regression analysis of skin sensitivity factors in type III and type IV photobiology skin found that the frequency of sleeping time and eating spicy food in the past of week could infect the sensitive skin evaluation dates statistically (P < .05). DISCUSSION/CONCLUSIONS: Skin sensitivity assessment results were impacted by seasonal transformation, living habits and customs, and facial regions. These indicted that we should consider above interfering factors when evaluated the skin sensitivity for getting more precise dates.

Assessment of Skin Physiology Change and Safety After Intradermal Injections With Botulinum Toxin: A Randomized, Double-Blind, Placebo-Controlled, Split-Face Pilot Study in Rosacea Patients With Facial Erythema.

BACKGROUND: Botulinum toxin (BTX) has been used cosmetically with good clinical efficacy and tolerable safety. OBJECTIVE: This randomized, double-blind, split-face clinical study aimed to investigate the efficacy and safety of intradermal BTX in patients with rosacea. MATERIALS AND METHODS: Twenty-four participants were enrolled and randomly given intradermal injections of BTX and normal saline in both cheeks. Clinician Erythema Assessment (CEA) score, Global Aesthetic Improvement Scale (GAIS) score, skin hydration, transepidermal water loss (TEWL), melanin content, erythema index, elasticity, and sebum secretions were evaluated at baseline and 2, 4, 8, and 12 weeks. RESULTS: On the BTX-treated side, the CEA score significantly decreased and the GAIS score significantly increased. The erythema index decreased at Weeks 4 and 8. Skin elasticity was improved at Weeks 2 and 4 and skin hydration, at Weeks 2, 4, and 8. However, TEWL and sebum secretion did not show significant differences. CONCLUSION: Intradermal BTX injections reduced erythema and rejuvenated the skin effectively and safely in patients with rosacea.

Assessment of Combined Ascorbyl Palmitate (AP) and Sodium Ascorbyl Phosphate (SAP) on Facial Skin Sebum Control in Female Healthy Volunteers.

The skin is fortified with a setup of lipophilic and hydrophilic, enzymatic and non-enzymatic antioxidant systems. Ascorbyl palmitate (AP) and sodium ascorbyl phosphate (SAP) are reported as lipophilic and hydrophilic antioxidants, respectively used for skin care. Present study was aimed to assess the combined AP (in oil phase) and SAP (in aqueous phase) via multiple emulsion (ME1) for controlling sebum secretions in healthy human females. FTIR analysis of AP and SAP was performed for identification. Multiple emulsions (ME1 and control) were prepared and analyzed for physical stability. Antioxidant activities of AP, SAP as well as ME1 (with combination of these compounds) were determined by DPPH method. 11 female volunteers were included in a single-blinded, placebo-controlled, split-face comparative study. Volunteers were instructed to apply ME1 on left cheek while control (without AP and SAP) on right cheek, for a period of 90 days. A non-invasive photometric device (Sebumeter®) was used for the measurement of sebum secretions on both sides of the face with subsequent time intervals. A good antioxidant activity of ME1 was observed. ME1 treatments reduced significant facial sebum secretions as compared with control/placebo treatments. It was concluded that combined AP and SAP supplementations to skin proved a promising choice for controlling facial sebum secretions and could be evaluated for undesired oily skin and acne reductions for beautifying the facial appearance.

Assessment of skin barrier function and biochemical changes of ex vivo human skin in response to physical and chemical barrier disruption.

Topical dermatotherapy is intended to be used on diseased skin. Novel drug delivery systems even address differences between intact and diseased skin underlining the need for pre-clinical assessment of different states of barrier disruption. Herein, we studied how short-term incubation in culture media compared to incubation in humidified chambers affects human skin barrier function and viability. On both models we assessed different types and intensities of physical and chemical barrier disruption methods with regard to structural integrity, biophysical parameters and cytokine levels. Tissue degeneration and proliferative activity limited the use of tissue cultures to 48h. Viability is better preserved in cultured tissue. Tape-stripping (50×TS) and 4h sodium lauryl sulfate (SLS) pre-treatment were identified as highly reproducible and effective procedures for barrier disruption. Transepidermal water loss (TEWL) values reproducibly increased with the intensity of disruption while sebum content and skin surface pH were of limited value. Interleukin (IL)-6/8 and various chemokines and proteases were increased in tape-stripped skin which was more pronounced in SLS-treated skin tissue extracts. Thus, albeit limited to 48h, cultured full-thickness skin maintained several barrier characteristics and responded to different intensities of barrier disruption. Potentially, these models can be used to assess pre-clinically the efficacy and penetration of anti-inflammatory compounds.

Assessment of Introital Lubrication.

Vaginal vasocongestion and lubrication serve to prepare the vaginal lumen for sexual activity. Lubrication is important for sexual functioning and difficulties with lubrication are one of the most commonly reported symptoms of sexual dysfunction. Few studies have empirically examined how vasocongestion and lubrication relate to one another and there are currently no well-established measures of lubrication. In this study, we designed and tested a simple method to assess lubrication at the vaginal introitus in 19 healthy women, using litmus test strips. We examined the relationship between lubrication and vaginal vasocongestion (measured with a photoplethysmograph) when elicited by audiovisual sexual stimuli (male-female sexual interactions). Lubrication was elicited by the sexual stimuli and was strongly correlated with reports of sexual arousal. Unexpectedly, lubrication was not correlated with vasocongestion, even though the latter was also elicited by the sexual stimuli. We discuss the implications of these findings for informing our understanding of the female sexual response and the potential clinical and scientific utility of this new measure.

Assessment of treatment efficacy and sebosuppressive effect of fractional radiofrequency microneedle on acne vulgaris.

BACKGROUND AND OBJECTIVE: A minimally invasive fractional radiofrequency microneedle (FRM) device has been used in skin rejuvenation and acne scars, and a recent pilot study demonstrated the positive therapeutic effect on acne. We evaluated the efficacy of FRM device for acne vulgaris in Asians and conducted objective measurement to assess its effect on sebum production. PATIENTS AND METHODS: Twenty Korean patients with acne vulgaris received a single full-face FRM treatment. Outcome assessments included standardized photography, physician's global assessment, patient's satisfaction scores, acne lesion count, and objective measurements of casual sebum level (CSL) and sebum excretion rate (SER). They were evaluated at baseline and 2, 4, 8 weeks after the treatment. RESULTS: After a single FRM treatment, the CSL and the SER showed 30-60% and 70-80% reduction, respectively, at week 2 (P < 0.01), and remained below the baseline level until week 8. Physician's global improvement scores for acne severity and acne lesion count also revealed clinical improvement with maximum efficacy at week 2, but returned to the baseline in most patients by week 8. Patients' satisfaction scores (0-4) were above 2 on average, and adverse effects were minimal. CONCLUSION: This prospective study demonstrated the sebosuppressive effect from a single FRM treatment, but its therapeutic efficacy in acne requires further evaluation.

Objective assessment of nanoparticle disposition in mammalian skin after topical exposure.

The use of nanoparticles as formulation components of topical drug delivery systems for the skin has been widely investigated in the literature. Because of the conflicting conclusions resulting from these studies concerning the ultimate disposition of the nanoparticles employed, the research presented in this paper has been designed to evaluate objectively the fate of such structures when administered to mammalian skin. Confocal microscopy images of skin exposed to nanoparticles have therefore been assessed by quantitative statistical analysis. Sebum on the skin surface was naturally fluorescent and clearly defined the outermost part of the cutaneous barrier. Fluorescent polystyrene nanoparticles applied in aqueous suspension could infiltrate only the stratum disjunctum, i.e., skin layers in the final stages of desquamation. This minimal uptake was independent of contact time (up to 16 h) and of nanoparticle size tested (20-200 nm). When skin barrier function was modestly compromised, the nanoparticles remained incapable of penetration beyond the most superficial layers, corresponding to a depth of 2-3 µm, of the stratum corneum (the outermost, 15-20 µm skin layer). Overall, these results demonstrate objectively and semi-quantitatively that nanoparticles contacting intact, and even partially damaged, skin cannot penetrate beyond the superficial layers of the barrier, and are highly unlikely, therefore, to reach the viable cells of the epidermis or beyond. It follows that nanoparticulate-based, topical delivery systems may prove useful as skin surface reservoirs from which controlled drug release over time may be achieved.

Behavioural responses of desert gerbil, Meriones hurrianae after removal of scent marking gland.

The desert gerbil, M. hurrianae scent marks the general substratum in its territory with the sebum exudation of mid abdominal gland and urine. Having assessed number of functions, which scent marking plays in the social life of these rodents, the scent marking behaviour was studied in animals, in which the gland was surgically removed and was compared with that of intact rodents. After recovery from the operation, the scent marking frequency of both male and female M. hurrianae declined significantly and was maintained at a low level. Surprisingly, scent marking with urine also declined considerable with time. After 5 months of the operation, desert gerbils were given a choice to respond to male and female sebum odours. The frequency of their scent marking with either sebum or urine did not show any significant enhancement as compared to their initial marking rate. However, the duration of their stay and scent marking frequency near the source of the sebum odour was more that in the clean side of the cage. The role of such altering behaviors of M. hurrianae and their impact on social organization are discussed.

Assessment of the kinetics of the antioxidative capacity of topical antioxidants.

While there is at least one standardized test available for evaluating the antioxidant capacity of cosmetic formulations, the authors proposed a new in vivo method to determine kinetics of squalene (SQ) photo-oxidation products (squalene monohydroperoxide, SQmOOH) as a reliable method with which to evaluate antioxidant capacity of a cosmetic formulation. Topical antioxidant formulation was applied on the foreheads of 30 volunteers. Sebum samples were collected before application of topical antioxidant and after one hour, three hours and five hours from the application of topical antioxidant. One half of the sebutape was irradiated and SQmOOH/SQ ratios in the skin lipid were analyzed using HPLC method. These results showed protective action of the topical antioxidant formulation against skin lipid peroxidation with a significant reduction of the quantity of SQmOOH (P<0.0001). Determination of the kinetics of squalene peroxidation is a reliable in vivo method in the evaluation of antioxidant capacity of cosmetic formulations.

Human percutaneous absorption of a direct hair dye comparing in vitro and in vivo results: implications for safety assessment and animal testing.

Although in vitro skin absorption studies often detect small residues of applied test material in the epidermis/dermis, it is uncertain whether the residue is within the living skin. We studied the dermal absorption of a hair dye hydroxyanthraquinone-aminopropyl methyl morpholinium methosulphate (HAM) in human skin in vivo and in vitro. In vivo, skin (back and scalp) received 0.5% HAM in a commercial formulation at 20microg/cm2 After 0.5 or 48h, skin was tape stripped, followed by cyanoacrylate biopsies (CAB). Sebum from scalp sites was collected for 48h. In vitro, skin was treated with 20mg/cm2 dye for 0.5h, penetration determined after 24h. In vivo, at 0.5h, total recovery (back) was 0.67microg/cm2 (tape strips+CAB). Fluorescence microscopy showed HAM in the hair follicle openings (HFO). At 0.5h, scalp tape strips contained 1.80microg/cm2, HFO 0.82microg/cm2. At 48h, HFO contained 0.21microg/cm2, sebum 0.80microg/cm2. In vivo, skin residues were in the non-living skin and eliminated via desquamation and sebum secretion. In vitro, the SC contained 1.50microg/cm2, epidermis/dermis 0.86microg/cm2, receptor fluid<0.04microg/cm2, a total of 0.90microg/cm2 was considered to be bioavailable. In vitro epidermis/dermis residues were nearly identical to those located in non-living skin in vivo. In conclusion, in vitro percutaneous penetration studies may produce seemingly bioavailable material , which raises the need for a Threshold of Skin Absorption (TSA) addressing a negligible dermal absorption in order to avoid unnecessary in vivo toxicity studies on substances that produce no significant human systemic exposure.

Assessment of etiologic agents in acne pathogenesis.

Acne is a chronic inflammatory disease of the pilosebaceous units. Traditional etiologic factors include increased sebum production, ductal hyperkeratosis, abnormality of the microbial flora within the pilosebaceous unit, and mediators of inflammation. Recent developments do not refute these familial elements, but rather refine particular aspects. Interleukin-1a influences hypercornification of the infundibulum as well as the inflammatory response by inducing the production of vascular endothelial growth factor in dermal papilla cells and follicular keratinocytes of the pilosebaceous unit. New retinoids have been developed based on controlling cellular proliferation and differentiation in the pilosebaceous unit by their action on nuclear receptors of cells. Dermal inflammation is not due to presence of bacteria, but from biologically active mediators produced by Propionibacterium acnes. The environment within the pilosebaceous unit is probably more important than the absolute number of P. acnes organisms. Indeed, the major role of the sebaceous gland appears to be supplying P. acnes needed nutrients. Moreover, the microbiologic principle of biofilms appears to be applicable to P. acnes in acne.

EEMCO guidance for the in vivo assessment of skin greasiness. The EEMCO Group.

Sebaceous gland activity has four distinct components which are sebum production (a secretion rate function), storage (a volume function), surface output (a delivery rate function) and stratum corneum permeation (an influx rate function). The oily appearance of skin results from an excess of sebum excretion and spreading over the body surface and its interaction with the skin surface. A multi-pronged approach is often useful to assess skin greasiness with precision. The clinical evaluation of skin greasiness and its shiny appearance should be further complemented by quantifying the large pores, follicular plugs and comedones. The sebum amount present at the skin surface can be measured non-invasively using one of several methods based on solvent extraction, cigarette paper pads, photometric assessment, bentonite clay and lipid-sensitive tapes. Quantitative parameters include the sebum casual level, the sebum excretion rate, the sebum replacement time, the instant sebum delivery, the follicular excretion rate, the density in sebum-enriched reservoirs and the sustainable rate of sebum excretion. A series of environmental and biological features influence the data. Hence rigorous methodological designs are mandatory to support claims. As a rule, accuracy of the methods is adversely affected by skin temperature, degree of hydration and surface roughness. An additional confounding factor is the inherent difficulty of collecting the surface lipids without a contribution from the follicular reservoir. A better understanding of factors that alter the sebum amount at the skin surface may well assist in the development of sebosuppressive agents to help the reduction of the skin greasiness and improve acne.

Effects of castration and testosterone on Fel dI production by sebaceous glands of male cats: I--Immunological assessment.

Fel dI is produced by salivary and sebaceous glands. Hormonal control of sebum production is clearly established. The influence of cat castration and supplementary treatment with testosterone on the production of sebum and Fel dI in cat skin have been researched in this study. On day 1, 12 male cats were anaesthetized and three skin areas carefully shaven. Then the level of lipids on skin surface was measured by means of a photometric method. Finally, the three areas of skin were washed with 5ml of distilled water through a plastic cylinder. Fel dI collected in the washes was measured with a two-site monoclonal antibody based ELISA. On day 2, six cats were castrated, the other six were used as a control group. Two and 4 weeks later, the levels of lipids and Fel dI in skin washes were measured again in all cats. On day 30, the six castrated cats were injected intramuscularly with prolonged-action testosterone. Two weeks later, quantification of lipids and Fel dI in all animals was repeated. Sebum and Fel dI levels decreased in all castrated animals. Injecting the castrated cats with testosterone led to a significant increase in sebum and Fel dI production. Our findings indicate that Fel dI production is influenced by the production of hormones.