Protective Creams Research Articles

The Inherent Capacitance of Moisturising Creams: A Source of False Positive Results?

The capacitance is a frequently used measurement of skin hydration in vivo, therefore any potential for false capacitance results is of importance. This in vitro study is to investigate the capacities of moisturising creams to cause false positive results. Adding different volumes of demineralised water and saline on dry clean plastic-backed tissue paper and measuring the capacitance values, the standard relation curve of capacitance value and volume of water was established. Four moisturising creams, petrolatum, a protective cream and a gel were then applied to the same kind of tissue paper in constant volumes, and were measured for weights and capacitance values over a 1-hour period allowing the gradual evaporation of water and volatile elements. A positive linear relationship was found between volume of water and capacitance value. All the creams had inherent capacitance that correlated with their water content. The inherent capacitance of creams decreased over time and ultimately reached comparable low values. The decrease in capacitance correlated significantly with weight reduction, except for petrolatum, which showed negligible inherent capacitance and weight reduction. The rates of decrease in capacitance value versus cream weight were significantly different for different creams. The results assured that capacitance value correlates to water content, and the inherent capacitance of creams may contribute to false positive skin capacitance in vivo if measured before water and other volatile elements of creams evaporate from the skin surface. In addition, the inherent capacitance and its durability may be relevant characteristics for further comparative studies of moisturisers and their clinical efficacy.

Development of reactive topical skin protectants against sulfur mustard and nerve agents.

The potential for highly reactive nanoparticles (RNP) to absorb destructively, i.e. to neutralize highly toxic substances such as the warfare agents GA, GB, HD and VX, has been demonstrated in the laboratory. Reactive nanoparticles represent a new class of nanoscale particles of metals and metal oxides that differ from other nanoparticles in reactivity and crystalline morphology. The potential for incorporating RNP into a protective barrier skin cream also has been demonstrated. Preliminary studies indicate that RNP are physically and chemically compatible with a base cream provided by the Army Medical Research Office and, importantly, remain reactive with chemical agents while promising to be compatible with skin contact.

Enjoying the sun well protected

According to the annual figures, skin cancer is the fastest growing type of cancer: one child in every hundred is currently at risk of developing a melanoma, the most malignant form of skin cancer. Surveys show that people are changing their behaviour when it comes to dealing with the sun. But only in small steps. That's why the Cancer League launches a sun protection campaign every year. Simple rules for protection from the sun: Between 11.00 a.m. and 3.00 p.m. (summer time), people should remain in the shade. A head covering and light, loose clothing should be worn in the sun. Tightly-woven, strong-coloured fabric offers better UV protection than coarsely-woven natural fibres. Sunglasses protect the eyes. The choice of sun screen depends on the skin type, the desired level of protection and the intended activity in the sun. The sun cream should be applied liberally half an hour before exposure to the sun. Depending on the particular preparation, it may need to be reapplied after bathing or showering to ensure that sun protection is maintained. Where reflective surfaces are present, e.g. sand, snow, cement and water, it is advisable to use sun protection creams even in the shade. Babies up to one year of age should be kept in the shade and sun protection agents should not be used on them. Like other chemical products, these may irritate the sensitive skin of babies and trigger allergies. Sunscreens used in older children should be waterproof, contain no alcohol and possess a high sun protection factor (at least SPF 15). Baby oil should not be used since it makes the child's skin even more sensitive to light. Parents should set an example to children in the way they protect themselves from the sun. Artificial UV light from sunbeds should be avoided, particularly by children and persons with an increased risk of developing a melanoma.

Experimentally induced chronic irritant contact dermatitis to evaluate the efficacy of protective creams in vivo

Background: Widely accepted in vivo models to evaluate the efficacy of protective creams (PCs) are still missing. Objective: The effect of petrolatum’s ability to protect against irritation was tested in a repetitive irritation test to optimize the concentration of irritants against which PCs are tested and to evaluate the necessary cumulative application time. Methods: On 20 healthy volunteers, the irritants (sodium lauryl sulfate 5% vs 10%, sodium hydroxide 0.5% vs 1%, lactic acid 20% vs 30%, and toluene undiluted) were applied daily for 2 weeks on the ventral forearms after 30 minutes of pretreatment with petrolatum. The irritant cutaneous reactions were quantified by erythema score, transepidermal water loss, and chromametry. Results: For petrolatum, a significant protective effect was obtained against irritation by sodium lauryl sulfate, sodium hydroxide, and toluene in different degrees. Less efficacy was observed against lactic acid. Conclusion: It was concluded that a 1-week period of cumulative irritation is enough to evaluate the efficacy of PCs against most irritants, even if lower concentrations of irritants are used. (J Am Acad Dermatol 1999;40:590-6.)

Ozone depletion, related UVB changes and increased skin cancer incidence

Stratospheric ozone at middle latitudes shows a seasonal variation of about ±20%, a quasi-biennial oscillation of 1–10% range and a long-term variation in which the level was almost steady up to about 1979 and declined thereafter to the present day by about 10%. These variations are expected to be reflected in solar UVB observed at the ground, but in an opposite direction. Thus UVB should have had a long-term increase of about 10–20%, which should cause an increase in skin cancer incidence of about 20–40%. Skin cancer incidence has increased all over the world, e.g. about 90% in USA during 1974–1990. It is popularly believed that this increase in skin cancer incidence is related to the recent ozone depletion. This seems to be incorrect, for two reasons. Firstly, the observed skin cancer increase is too large (90%) compared with the expected value (40%) from ozone depletion. Secondly, cancer does not develop immediately after exposure to solar UVB. The sunburns may occur within hours; but cancer development and detection may take years, even decades. Hence the observed skin cancer increase since 1974 (no data available for earlier periods) must have occurred due to exposure to solar UVB in the 1950s and 1960s, when there was no ozone depletion. Thus, the skin cancer increase must be attributed to harmful solar UVB levels existing even in the 1960s, accentuated later not by ozone depletion (which started only much later, by 1979) but by other causes, such as a longer human life span, better screening, increasing tendencies of sunbathing at beaches, etc., in affluent societies. On the other hand, the recent ozone depletion and the associated UVB increases will certainly take their toll; only that the effects will not be noticed now but years or decades from now. The concern for the future expressed in the Montreal Protocol for reducing ozone depletion by controlling CFC production is certainly justified, especially because increased UVB is harmful to animal and plant life also. However, because the increased cancer incidence observed so far may not be (entirely) due to ozone depletion, other causes need to be investigated urgently and, if possible, remedied. Otherwise, deaths due to skin cancer will continue even after CFC production is controlled and ozone levels are recovered. There is no room for complacency. If nothing else is possible, use of protective screens and creams and avoiding exposure to sunlight during peak hours (10:00–15:00 h) should be strongly recommended. © 1998 John Wiley & Sons, Ltd.

Ozone depletion, related UVB changes and increased skin cancer incidence

Stratospheric ozone at middle latitudes shows a seasonal variation of about ±20%, a quasi-biennial oscillation of 1–10% range and a long-term variation in which the level was almost steady up to about 1979 and declined thereafter to the present day by about 10%. These variations are expected to be reflected in solar UVB observed at the ground, but in an opposite direction. Thus UVB should have had a long-term increase of about 10–20%, which should cause an increase in skin cancer incidence of about 20–40%. Skin cancer incidence has increased all over the world, e.g. about 90% in USA during 1974–1990. It is popularly believed that this increase in skin cancer incidence is related to the recent ozone depletion. This seems to be incorrect, for two reasons. Firstly, the observed skin cancer increase is too large (90%) compared with the expected value (40%) from ozone depletion. Secondly, cancer does not develop immediately after exposure to solar UVB. The sunburns may occur within hours; but cancer development and detection may take years, even decades. Hence the observed skin cancer increase since 1974 (no data available for earlier periods) must have occurred due to exposure to solar UVB in the 1950s and 1960s, when there was no ozone depletion. Thus, the skin cancer increase must be attributed to harmful solar UVB levels existing even in the 1960s, accentuated later not by ozone depletion (which started only much later, by 1979) but by other causes, such as a longer human life span, better screening, increasing tendencies of sunbathing at beaches, etc., in affluent societies. On the other hand, the recent ozone depletion and the associated UVB increases will certainly take their toll; only that the effects will not be noticed now but years or decades from now. The concern for the future expressed in the Montreal Protocol for reducing ozone depletion by controlling CFC production is certainly justified, especially because increased UVB is harmful to animal and plant life also. However, because the increased cancer incidence observed so far may not be (entirely) due to ozone depletion, other causes need to be investigated urgently and, if possible, remedied. Otherwise, deaths due to skin cancer will continue even after CFC production is controlled and ozone levels are recovered. There is no room for complacency. If nothing else is possible, use of protective screens and creams and avoiding exposure to sunlight during peak hours (10:00–15:00 h) should be strongly recommended. © 1998 John Wiley & Sons, Ltd.

Optimization of the repeated irritancy test (RIT) for the efficacy assessment of protective creams

Optimization of the repeated irritancy test (RIT) for the efficacy assessment of protective creams

New look for protective and aftercare creams

New look for protective and aftercare creams

PREVENTION OF IRRITANT CONTACT DERMATITIS: New Aspects

Contact dermatitis is the most frequent manifestation of occupational skin disease. Apart from total elimination of cutaneous exposure to hazardous substances, no established forms of treatment exist for irritant contact dermatitis (ICD). Furthermore, ICD is an accepted risk factor for allergic contact dermatitis (ACD). Due to these circumstances, prevention should have obvious priority to reduce the incidence and prevalence of ICD and secondary ACD. Primary, secondary, and tertiary prevention should be distinguished. Primary prevention tries to prevent the development of disease in the healthy individual. Secondary prevention is targeted at the diseased individual trying to inhibit a relapse of contact dermatitis. In tertiary prevention (rehabilitation), a chronically diseased patient is treated and reintegrated into the working environment. Prevention of occupational contact dermatitis requires an integrated approach that considers both the exposure and the exposed individual. The responsibility for primary prevention rests mainly with manufacturers and producers of chemicals and products, government agencies, consumer organizations, industrial physicians and nurses, and safety engineers. 34 A multidimensional approach with eight basic elements of prevention planning has been proposed by Mathias 26 : 1Recognition of potential cutaneous irritants and allergens 2Engineering controls or chemical substitution to prevent skin exposure 3Personal protection with appropriate clothing or protective creams 4Personal and environmental hygiene 5Regulation of potential allergens and irritants within the workplace 6Educational efforts to promote awareness of potential allergens and irritants 7Motivational techniques to promote safe work conditions and practices 8Pre-employment and periodic health screening (Table 1)

Self-application of a Protective Cream

To determine if a protective cream (PC) is adequately applied to the hands by workers in several occupations and to quantify what areas are covered or missed. Prospective diagnostic study. Metalworking factory, construction sites, and university hospital. One hundred fifty healthy volunteers (50 from each setting) were recruited for a questionnaire interview and typical self-application of a PC. None. Percentage of sufficient cover with PC as assessed with fluorescence under Wood light. Many areas were skipped when viewed under Wood light. The application of PC was incomplete, especially on the dorsal aspects of the hands. Individuals should be made aware of the most commonly missed regions to ensure complete skin protection. This simple method is a useful adjunct to quantify self-application and in worker education.

Self-application of a protective cream. Pitfalls of occupational skin protection

Self-application of a protective cream. Pitfalls of occupational skin protection

Training workers at risk for occupational contact dermatitis in the application of protective creams: efficacy of a fluorescence technique

Training workers at risk for occupational contact dermatitis in the application of protective creams: efficacy of a fluorescence technique

Skin problems in sugar artists

Sugar artistry is a growing profession amongst bakers and confectioners and an increasingly common hobby in amateur cooks. The main work consists of manual manipulation of sugar which is formed into figures and objects for table and food decoration. The sugar must be warmed up to 50 degrees C in order to be liquid and malleable and so the artists suffer from diverse thermally induced skin problems on their hands. Such changes have not to date been reported in the dermatological literature. In this study we report our experience in 50 Swiss sugar artists who have suffered from skin problems. The study took the form of a questionnaire survey. The response rate was 30 out of 50. Twenty-six reported no chronic skin disorder. Four suffered from a palmar vesicular relapsing type of chronic eczema. The main skin problems on the hands during work with hot sugar were increased sweating, seen in 20 out of 30 (67%), and burning with erythema and blistering, seen in 12 out of 30 (40%). Most participants (83%) were highly irritated by the skin problems during their work, and applied a protective cream before working with sugar, or wore rubber gloves. Topical therapy with a preparation containing 10% aluminium chloride hexahydrate, used once daily for 3 weeks, evaluated in 14 participants, decreased sweating in 10 (71%) and reduced the thermally induced erythema in one (7%).

Efficacy of protective creams and/or gels.

Efficacy of protective creams and/or gels.

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 lauryl sulphate (5% aq.; 30 min), sodium hydroxide (0.5% aq.; 2 min), and toluene (20% eth.; 2 min). The barrier 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 transepidermal water loss (TEWL) by evaporimetry 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 (Stokoderm) significantly suppressed the irritation due to sodium lauryl sulphate and toluene, the other (Contra-Alkali) 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.

Sodium hydroxide-induced subclinical irritation. A test for evaluating stratum corneum barrier function.

This report concerns the development of a short, simple, non-invasive test for assessing sensitivity to irritant dermatitis. Application of NaOH (0.005-2.0 mol/l) to human skin resulted in significantly greater skin surface water loss directly after exposure (1-15 min) than of control (water). The increase in skin surface water loss after NaOH application was dose-dependent (0.005-0.1 mol/l) and application time-dependent (1-10 min). Application times exceeding 10 min did not further increase skin surface water loss and doses higher than 0.1 mol/l reversed the effect on skin surface water loss. 15 min after removal of the alkali, skin surface water loss baseline values were almost regained. This procedure did not cause visible reactions or discomfort for the volunteers. In a subsequent experiment, volunteers were exposed to 0.2 mol/l NaOH for 5 min on one forearm and to 1% sodium lauryl sulfate for 24 h contralaterally. Skin surface water loss after 5 min of NaOH application was significantly correlated with transepidermal water loss measurements after 24 h of sodium lauryl sulfate patch application. This is, to our knowledge, the first description of a procedure for quantifying interindividual differences in stratum corneum barrier function without inducing visible changes or causing volunteers discomfort. Use of this model should help to further investigate skin barrier function as well as to test protective devices and barrier creams.

An animal model to determine sunscreen protectiveness against both vascular injury and epidermal cell damage

Sunscreen preparations can reduce the erythemogenic (sunburning) effects of solar ultraviolet radiation (UVR). Less is known about the ability of sunscreens to protect against other forms of UYR-induced damage. This study was designed to yield data on epidermal cell damage at UVR doses sufficient to provoke vascular changes (edema and erythema) in hairless mice, and to determine the comparative effectiveness of a commercial sunscreen in protecting against these two criteria of injury. The sunscreen (Piz Buin 12 Sun Protection Cream) was used at full concentration and at three serial dilutions. The dorsa of 144 hairless mice were treated with one of six sunscreen or vehicle preparations and subsequently irradiated with one of six exposures to an appropriately filtered xenon arc solar simulator. Vascular responses were determined by observing the animals for alterations in the gross appearance of the treated and irradiated sites (edema and erythema). Epidermal cell damage was assessed by determining the sunburn cell (SBC) indices in the epidermis removed 24 hours after irradiation. Both the vascular responses and SBC indices indicated that the sunscreen provided concentration-dependent protection against radiation damage. Furthermore, SBC indices provided a relatively continuous variable for quantification of sunscreen effectiveness.

Summertime Actinic Lichenoid Eruption

A distinct summertime skin disorder seen in 25 Indian patients is described under a tentative designation of summertime actinic lichenoid eruption (SALE). The eruption predominantly affects females in their 2nd to 4th decade. The initial lesions are in the form of closely aggregated pruritic lichenoid papules starting during summer months on the exposed parts of the body. The lesions respond favourably to sun protection and corticosteroid cream but the recurrences are common during the subsequent summers when the lesions tend to become more persistent, pruritic and lichenified. Histopathologic features include early basal cell degeneration, spongiotic vesiculation with or without focal parakeratosis and an intense lymphocytic infiltrate in the dermis. In spite of strong clinical evidence of relation to sunlight, the lesions are not easily reproducible by artificial light.

Fluorochemical resin complexes for use in solvent repellent hand creams.

A fluorochemical (FC)-resin complex has been developed for use in protective hand creams. Hand creams incorporating this new technology effectively repel solvents and resist their penetration into the skin. The in vitro studies conducted to determine the efficacy of the formulated FC-resin complex include solvent penetration through treated filter paper, solvent repellency on treated pigskin, and penetration of radio tagged sodium lauryl sulfate through treated hairless mouse skin. In vivo studies demonstrate that this new technology does aid in reducing irritation caused by solvent contact.

Simple method to determine the efficiency of a cream used for skin protection against solvents.

Guillemin, M., Murset, J. C., Lob, M., and Riquez, J. (1974). British Journal of Industrial Medicine, 31, 310-316. Simple method to determine the efficiency of a cream used for skin protection against solvents. Most of the industrial organic solvents coming into contact with the skin are absorbed through it and enter the blood. They can then be detected in the breath, the analysis of which makes it easy to evaluate skin absorption. Such an evaluation can be made with and without the use of a skin protective (barrier) cream. A comparison of the results allows the efficiency of the cream to be tested. An example of the application of this method is described. The solvent was toluene and the cream tested was composed mainly of talc, glycerol, and water. Ten male volunteers exposed their hands to liquid toluene for 10 minutes. The elimination of the solvent was followed by breath analysis up to 3 hours after the exposure. Two or more sets of exposure were made under different conditions with and without the protective cream. The results show a good standard of efficiency when the cream is carefully and deeply applied. The efficiency of the cream was determined by testing the difference between the decay curves obtained with and without the barrier cream. A relative efficiency was estimated as a percent diminution of solvent excretion by taking the excretion after exposure of unprotected skin as 100%. It is shown that skin absorption for toluene compared with lung absorption may be important and has to be estimated where total exposure is concerned. The method devised here appears to offer simplicity. It is presented as a laboratory test to show the intrinsic value of the cream but its applicability in the field is also considered.