Cutting oil dermatitis on guinea pig skin

The effect of repeated exposure of cutting oil on 8 guinea pigs' skin was evaluated by visual scoring for erythema and skin water vapour loss (SVL) measurement over a 6-week period. The visual scores (measuring severity of erythema) and SVL values were significantly higher on skin treated with cutting oils (positive control) compared to untreated skin (negative control) throughout the study period. The scores and SVL values returned to near-baseline values when cutting oil application was stopped. In addition, the effect of 2 "after-work" emollient creams on 8 guinea pigs' skin repeatedly treated with a cutting oil was assessed by similar methods. The visual scores and SVL values of guinea pig skin that was repeatedly treated with the cutting oil and moisturized with "after-work" emollient creams, were significantly higher than negative and positive control guinea pig skin. It appeared that the 2 "after-work" emollient creams do not alleviate the irritant effect of the cutting oil on guinea pig skin. They appeared to aggravate the irritant effect of the cutting oil.     

Allergic contact dermatitis from di-isodecyl phthatate in a polyvinyl chloride identity band

An animal model for the evaluation of skin protective creams against chemical irritants is described. The irritants were applied daily for 2 weeks to shaved back skin of young guinea pigs: sodium tauryl sulphate (5% aq.: 30 min), sodium hydroxide (0,5% aq.; 2 min). and toluene (20′i. eth.; 2 mint. “The harrier cream was applied 2 h prior to and immediately after exposure to the irritant. Control animals were treated with the irritant only. The irritant reaction was scored on a 4–point scale for erythema and quantified with regard to transepidennal water loss (TEWL) by evaporime-try and skin blood flow volume (BFV) by laser Doppler velocimetry. A total of 90 guinea pigs, consisting of” individual panels of 5 to 10 animals, was tested. While one barrier cream (Slokoderm) significantly suppressed the irritation due 10 sodium lauryl sulphate and toluene, the other (Contra-Alkalh failed to do so and even aggravated the response, which was particularly evident with sodium hydroxide. This model may be useful in developing more effective barrier creams.     

Efficacy of skin barrier creams

An animal model for the evaluation of skin protective creams against chemical irritants is described. The irritants were applied daily for 2 weeks to shaved back skin of young guinea pigs: sodium tauryl sulphate (5% aq.: 30 min), sodium hydroxide (0,5% aq.; 2 min). and toluene (20'i. eth.; 2 mint. "The harrier cream was applied 2 h prior to and immediately after exposure to the irritant. Control animals were treated with the irritant only. The irritant reaction was scored on a 4–point scale for erythema and quantified with regard to transepidennal water loss (TEWL) by evaporime-try and skin blood flow volume (BFV) by laser Doppler velocimetry. A total of 90 guinea pigs, consisting of" individual panels of 5 to 10 animals, was tested. While one barrier cream (Slokoderm) significantly suppressed the irritation due 10 sodium lauryl sulphate and toluene, the other (Contra-Alkalh failed to do so and even aggravated the response, which was particularly evident with sodium hydroxide. This model may be useful in developing more effective barrier creams.     

Percutaneous absorption of 3 organic solvents in the guinea pig (III). Effect of barrier creams

The efficacy of 4 barrier preparations presented as cream or foam against percutaneous absorption of organic solvents was investigated in the guinea pig. An ordinary hand cream was also tested. Slight reduction in blood concentration of the solvents was seen when normal skin treated with barrier creams was exposed. Absorption of butanol through stripped skin treated with barrier creams was higher than absorption through skin not so treated. Barrier creams can be considered to give poor skin protection against the organic solvents investigated.     

Barrier recovery and influence of irritant stimuli in skin treated with a moisturizing cream

Moisturizers are used daily by many people to alleviate symptoms of clinically and subjectively dry skin. Recent studies suggest that certain ingredients in creams may accelerate the recovery of a disrupted barrier and decrease the skin susceptibility to irritant stimuli. In the present single-blind study, a moisturizing cream was tested for its influence both on barrier recovery in surfuctant-damaged skin and on the susceptibility of normal skin to exposure to the irritant sodium lauryl sulphate (SLS). Parameters measured were transepidermal water loss (TEWL) and skin corneometer values, indicating degree of hydration. Treatment of surfactant-damaged skin with the test cream for 14 days promoted barrier recovery, as observed as a decrease in TEWL. Skin corneometer values also normalized more rapidly during the treatment. In normal skin, use or the test cream significantly reduced TFWL after 14 days of treatment, and irritant reactions to SLS were, significantly decreased. Skin corneometer values increased after only 1 application and remained elevated after 14 days. In conclusion, the accelerated rate of recovery of surfactant-damaged skin and the lower degree of SLS-induced irritation in normal skin treated with the test cream may be of clinical relevance in attempts to reduce contact dermatitis due to irritant stimuli.     

Bioengineering measurements of barrier creams efficacy against toluene and NaOH in an in vivo single irritation test

Background/aims: By now, only a few models have been published with the goal of testing barrier creams in vivo in humans. The aim of this study was to evaluate with a single irritation test, barriers creams in humans against a lipophilic and a hydrophilic irritant, toluene and NaOH, respectively.
Methods: Both irritants were applied for 15 min after pretreatment of the skin with barrier creams. Non-invasive bioengineering methods, such as skin colorimetry (a*) and cutaneous blood flow (CBF) measurements were used to assess product protection.
Results: After toluene application on control sites, the irritation appeared quickly (T_max=3 min after patch removal), was significant (+5-6 units for a* and+80% for CBF) and did not return to base value within 1 h. Skin irritation after NaOH application, as measured by a*, was less important (+2 units) and occurred later ( T "max=40 min after patch removal). For this irritant, CBF response was minor and variable. When testing barrier properties of the products, none of them were able to prevent the skin erythema induced by toluene. Against NaOH, one barrier cream as well as petrolatum and a fatty cream protected the skin significantly.
Conclusion: The present study points out the unsatisfactory effectiveness of several commercially available barrier creams claimed to protect against lipophilic or hydrophilic irritants.     

Effect of mineral oil and linoleic-acid-containing emulsions on the skin vapour loss of sodium-lauryl-sulphate-induced irritant skin reactions

This study evaluates the influence of mineral oil and linoleic-acid-containing emulsions on the skin vapour loss (SVL) of detergent-induced irritant skin reactions. During a period of 2 weeks, 2 x 45 min applications of a sodium lauryl sulphate solution of low molarity were performed on the forearm of 9 volunteers. In the same period, a standard amount of each emulsion was applied on the induced irritant skin reactions, 3 times each day. The effect of the emulsions on the barrier function of the skin was evaluated by means of SVL measurements. The emulsion based on mineral greases significantly reduced SVL values during both weeks, possibly because of an occlusive effect. The emulsion with 15% of linoleic acid significantly reduced SVL values during the 1st week but not during the 2nd week. The emulsion with 38% of linoleic acid did not reduce SVL values at all.     

Changes in skin barrier function following long-term treatment with moisturizers, a randomized controlled trial

BACKGROUND: Moisturizers are commonly used by patients with dry skin conditions as well as people with healthy skin. Previous studies on short-term treatment have shown that moisturizers can weaken or strengthen skin barrier function and also influence skin barrier recovery. However, knowledge of the effects on skin barrier function of long-term treatment with moisturizers is still scarce. OBJECTIVES: To investigate the impact of long-term treatment with moisturizers on the barrier function of normal skin, as measured by transepidermal water loss (TEWL) and susceptibility to an irritant, and to relate those effects to the composition of the designed experimental moisturizers. METHODS: Volunteers (n = 78) were randomized into five groups. Each group treated one volar forearm for 7 weeks with one of the following preparations: (i) one of three simplified creams, containing only a few ingredients in order to minimize the complexity of the system; (ii) a lipid-free gel; (iii) one ordinary cream, containing 5% urea, which has previously been shown to decrease TEWL. The lipids in the simplified creams were either hydrocarbons or vegetable triglyceride oil, and one of them also contained 5% urea. After 7 weeks, treated and control forearms were exposed for 24 h to sodium lauryl sulfate (SLS) using a patch test. TEWL, blood flow and skin capacitance of both SLS-exposed and undamaged skin were evaluated 24 h after removal of patches. Additionally, a 24-h irritancy patch test of all test preparations was performed on 11 volunteers in order to check their possible acute irritancy potential. RESULTS: Changes were found in the barrier function of normal skin after 7 weeks of treatment with the test preparations. The simplified creams and the lipid-free gel increased TEWL and skin response to SLS, while the ordinary cream had the opposite effect. One of the simplified creams also decreased skin capacitance. All test preparations were shown to be nonirritant, both by short-term irritancy patch test and by measurement of blood flow after long-term treatment. CONCLUSIONS: Moisturizers influence the skin barrier function of normal skin, as measured by TEWL and susceptibility to SLS. Moreover, the effect on skin barrier function is determined by the composition of the moisturizer. The ingredients which influence the skin barrier function need to be identified, and the mechanism clarified at the molecular level.     

Water protective effect of barrier creams and moisturizing creams: a new in vivo test method

Frequent exposure to water is an important risk factor for the development of irritant hand eczema. Evaluation of cream efficacy in protecting against water is difficult. A new non-irritant, non-invasive method is introduced, based on evaluation of colour intensities when an aqueous solution of crystal violet is applied to the skin, after pretreatment with different creams. By skin reflectance measurement, differences in colour intensity were objectified. Measurements of transepidermal water loss were also performed. 2 barrier creams and a moisturizer were tested on the dorsal and volar aspects of the handy One barrier cream contained silicone the other solid particles. The moisturizer had a high content of lipid. In one experiment, the immediate effect of the cream in protecting against water was evaluated. In a second experiment, the water resistancy of the creams was tested, using a standard water immersion procedure (4X20 min). The barrier cream with particles gave the best immediate protection (dorsal 76% volar 69%). The moisturizer was intermediately protective (dorsal 57% volar 34%) while very link protection was found for the silicone-containing cream (dorsal 16% volar 10%). The water immersion procedure resulted in only minor changes in protection for each cream. When comparing transepidermal water loss in the treated areas with pretreatment values, a reduction was recorded only for the particle-containing barrier cream. The colour method described may be used as a quick and easy test of the protective effect of creams against water.     

The effect of 4 barrier creams on the absorption of water, benzene, and formaldehyde into excised human skin

The effect of 4 barrier creams on the absorption of (3H)-water (14C)-benzene and (14C)-formaldehyde into excised human skin was studied. The control skin and the barrier cream treated skin were exposed to the test substance for 0.5 hr, whereupon the amount absorbed was determined. The results indicated that the experimental cream "Water barrier" reduced the absorption of water and benzene but not formaldehyde. Kerodex 71 cream slightly reduced the absorption of benzene and formaldehyde. The barrier creams Petrogard and "Solvent barrier" did not affect the absorption of any of the substances studied. The use of these creams against percutaneous absorption is questioned.     

Hydrogel barrier/repair creams and contact dermatitis.

BACKGROUND: Barrier creams are important to protect the skin in occupations with chemical exposure. The value of hydrogels in barrier creams has never been studied. OBJECTIVE: The purpose of this study was to evaluate the current technology in barrier cream formulation and explore the utility of hygrogels in skin protection. METHODS: A total of 80 men, women, and children between the ages of newborn to 80 years >were studied with the following dermatologic conditions: household hand dermatitis (21), occupational hand dermatitis (18), latex glove irritant contact dermatitis (9), diaper dermatitis (5), cutaneous wounds (17), and allergic contact dermatitis (ACD) (10). In this study, the investigators used a split body approach, in a double-blind randomized fashion, where one body site was treated with a traditional petrolatum-based cream while the other body site was treated with a hydrogel-based barrier/repair cream. Both subject and investigator assessments were recorded by questionnaire. RESULTS: The hydrogel barrier/repair cream showed better skin improvement than the petrolatum-based cream in both subject assessment (62%, P =.0048) and investigator assessment (75%, P =.0000003). CONCLUSION: Hydrogel barrier/repair creams might represent a new, effective approach to skin protection.     

Impact of glove occlusion on cumulative skin irritation with or without hand cleanser–comparison in an experimental repeated irritation model

Background. Irritant contact dermatitis remains a substantial problem in the food processing industries. Irritants that are weak by themselves, such as glove occlusion and mild detergents, could interact to produce contact dermatitis. Objectives. To model the irritant action of an antibacterial hand cleanser and glove occlusion, with sodium lauryl sulfate (SLS) as a positive control. The effects of a pre‐exposure cream and a post‐exposure cream were also investigated. Methods. A modified repeated short‐time occlusive irritation test with 20 healthy volunteers, and application of irritants over 4 days, with pre‐exposure and post‐exposure creams and overnight glove occlusion, was performed. The changes in transepidermal water loss (TEWL) served as a measure of the irritant damage to the epidermal barrier. Results. The antibacterial cleanser and the glove occlusion separately induced only minor increases in TEWL. When combined, the two showed a tandem effect, as the TEWL increase was significantly higher, and was similar to that seen with the positive control, SLS. The pre‐exposure and post‐exposure creams alone significantly mitigated the cumulative irritation, and this effect was strongest when the two creams were combined. Conclusions. Irritant contact dermatitis may develop through the tandem effects of long‐term glove occlusion and the accumulation of barrier damage from hand washing, even when mild hand cleansers are employed.     

In-situ evaluation of barrier-cream performance on human skin using laser-induced breakdown spectroscopy

Laser-induced breakdown spectroscopy (LIBS) was used to evaluate the effect of barrier creams (skin protective creams) on human skin. A Nd: YAG laser at 1,064 nm was used with a pulse energy of 100 mJ. A method was developed to measure the effectiveness of barrier creams against zinc ion absorption from aqueous zinc chloride solution and oil paste zinc oxide, which represent model hydrophilic and lipophilic metal compounds, respectively. Zinc was chosen since it posed no risk to human skin. 3 representative commercial barrier creams advertised as being effective against lipophilic and hydrophilic substances were evaluated by measuring zinc absorbed through the stratum corneum. 4 consecutive skin surface biopsies (SSB) were taken from biceps of the forearms of 6 volunteers at time periods of 0.5 h and 3 h after application of the protective cream. Results were compared with control skin where no barrier cream was used. The zinc atomic emission line at 213.9 nm was selected. Gate delay and gate width time was optimized to obtain the best signal-to-noise ratio (SNR) and precision. This method provided a facile and rapid screening of the effectiveness of skin barrier creams against zinc ion penetration. The barrier creams were shown to provide appreciable protection against the penetration of both ZnCl2 and ZnO into the skin.     

Skin protection against ionized cobalt and sodium lauryl sulphate with barrier creams

853 individuals who are still working or had previously worked in hard metal manufacture were examined and selected for patch tests with materials from their working environment including metal allergens. The majority of the individuals with positive test reactions to cobalt chloride were retested with serial dilutions of cobalt chloride and with the same serial dilutions after preparation of the skin with a layer of barrier or emollient cream used for hand care in this factory. The irritant effect of sodium lauryl sulphate (SLS) was similarly investigated. The barrier and emollient creams did not give any protection against cobalt chloride or sodium lauryl sulphate. In fact they seemed to enhance the penetration of cobalt ions. Their use in protection against metal allergens and cutting fluids is questionable.     

Protective effect of barrier creams and spray coatings against epoxy resins

This study evaluates the protective capacity of 4 barrier creams and 2 methacrylate spray coatings against skin contact with epoxy resins. The effect of these materials on the strength and on the surface area of patch test reactions caused by epoxy resin was assessed in 11 volunteers with a known allergy to epoxy resins. Standard amounts of barrier cream and spray coating were applied on the skin. Then patch tests were carried out with epoxy resin on the pretreated sites. After 24 h patches were removed, 48 h thereafter the strength and surface area of the reactions were scored. Results were compared with the score of a control test. The use of 2 barrier creams resulted in a significant reduction of the surface area of the patch test reactions. Spray coatings significantly reduced both the strength and the surface area of the reactions. Our results suggest that methacrylate spray coatings and barrier creams may provide protection against epoxy resins during a test period of 24 h. However, the development of new formulations, adapted more specifically to this purpose, is necessary.     

Topical antioxidants protect the skin from chemical-induced irritation in the repetitive washing test: a placebo-controlled, double-blind study

Background. There is increasing evidence that reactive oxygen species play an important role in the development of both irritant and allergic contact dermatitis. Objectives. To assess the potential of topical antioxidants to prevent the development of experimentally induced irritant contact dermatitis. Methods. We evaluated the effect of a cream containing a combination of antioxidants on sodium lauryl sulfate-induced irritant contact dermatitis in the repetitive washing test. As readout parameters for skin barrier function and cutaneous inflammation stratum corneum hydration, cutaneous blood flow and transepidermal water loss were assessed in 25 volunteers with bioengineering methods. Results. In comparison with the cream base and a frequently used barrier cream, the antioxidant cream had high radical scavenging activity and effectively protected the skin from chemical-induced irritation. Conclusions. The superiority of the cream with antioxidants to the cream base suggests that reactive oxygen species, at least in part, play a role in the development of irritant contact dermatitis.     

Improvement in skin barrier function in patients with atopic dermatitis after treatment with a moisturizing cream (Canoderm)

Patients with atopic skin show a defective barrier function both in rough and in clinically normal skin, with an increasing risk of developing contact dermatitis. Moisturizing creams are often used in the treatment of dry skin. The purpose of this study was to investigate the influence of treatment with a urea-containing moisturizer on the barrier properties of atopic skin. Fifteen patients with atopic dermatitis treated one of their forearms twice daily for 20 days with a moisturizing cream. Skin capacitance and transepidermal water loss (TEWL) were measured at the start of the study and after 10 and 20 days. On day 21 the skin was exposed to sodium lauryl sulphate (SLS) and on day 22 the irritant reaction was measured non-invasively. Skin capacitance was significantly increased by the treatment, indicating increased skin hydration. The water barrier function, as reflected by TEWL values, tended to improve (P = 0.07), and the skin susceptibility to SLS was significantly reduced, as measured by TEWL and superficial skin blood flow (P < 0.05). Thus, it seems that certain moisturizers could improve skin barrier function in atopics and reduce skin susceptibility to irritants. The mechanism and the clinical relevance need further investigation.     

Effect of barrier creams: human skin in vivo

An in vivo method was developed to measure the effectiveness of skin protective creams against 2 dye indicator solutions: methylene blue in water and oil red O in ethanol, representative of model hydrophilic and lipophilic compounds, 3 representative barrier creams commercialized as effective against lipophilic, hydrophilic, or lipophilic and hydrophilic substances were assayed by measurements of the dye in cyanoacrylate strips of protected skin samples after various application limes. The flexural surfaces of the forearms of 6 normal volunteers (3 female and 3 male, mean age 26.8±4.1 years) were treated. The method was as follows: solutions of 5% methylene blue in water and 5% oil red O in ethanol were prepared, and applied to untreated skin and protective-cream-pretreated skin with the aid of aluminum occlusive chambers, for 0 h and 4 h, respectively. At the end of the application time, the creams were removed. Consecutive skin surface biopsies (SSB) from 1 to 4 strips were taken. The amount of stain in each strip was determined by colorimetry, and the cumulative amount of stain from 1 to 4 strips in each measurement was calculated. The cumulative amount represents the amount of permeation of each solution at each time point, and the efficacy of skin barrier cream. The results showed one formulation at both 0 h and 4 h reduced the amount of permeation of melhylene blue (p<0.0l) and oil red O (p<0.01) compared with the control group. Another formulation was protective against the permeation of oil red O (p < 0.0l). but not against methylene blue at 0 h and 4 h; it was not significantly different at 0 h versus 4 h. The 3rd formulation produced increased cumulative amounts to oil red O at both 0 h and 4 h (p<0.05); it also increased permeation amounts to methylene blue (p<0.05) after 4 h. This model appears a facile, rapid and objective early screen to evaluate the efficacy of skin barrier creams in vivo, as well as their individual ingredients.     

Instrumental and dermatologist evaluation of the effect of glycerine and urea on dry skin in atopic dermatitis

Background/aims: Moisturising creams are useful treatment adjuncts in inflammatory dermatoses and have beneficial effects in the treatment of dry, scaly skin. The effects on dryness and skin permeability of a new moisturising cream with 20% glycerine was compared with its placebo and with a medicinally authorised cream with 4% urea (combined with 4% sodium chloride) in the treatment of dry skin.
Methods: Patients ( n =109) with atopic dermatitis were treated for 30 days with a moisturiser in a randomised, parallel and double-blind fashion. Transepidermal water loss (TEWL) and skin capacitance were assessed instrumentally, and changes in the dryness of the skin were assessed by the dermatologist.
Results: No difference in TEWL was found between glycerine treatment and its placebo, whereas a lower value was found in the urea-treated area compared to the glycerine-treated area. No difference in skin capacitance was found. The clinical assessment of dryness showed urea to be superior to glycerine in treating the condition.
Conclusions: Moisturising creams are different, not only with respect to composition but also with respect to their influence on skin as a barrier to water in patients with atopic dermatitis.     

New cosmetic emulsions for dry skin

The aim of this study was to formulate stable water-in-oil (w/o) emulsions containing oils with a high percentage of fatty acids, sterols, vitamins, cholesterol, and ceramides in order to improve topical treatment of dry skin conditions. Two w/o emulsions were developed and physicochemical characterized. The biological effects of the formulations were assessed on the volar surface of the human foreharm over 28 days. The results obtained showed that areas treated by either cream were significantly different from the control area, as assessed by epidermal capacitance and sebometry over the 28 days. Treatment with cream containing ceramides presented higher values of sebometry and corneometry. According to the sensory evaluation performed, both creams were found to have good acceptability.