Efficacies of a barrier cream and an afterwork emollient cream against cutting fluid dermatitis in metalworkers: a prospective study

Effectiveness of a Skin Care Program With a Cream Containing Ceramide C and a Personalized Training for Secondary Prevention of Hand Contact Dermatitis

Background/Objectives: The aim of our study was to investigate the effectiveness of personalized training on skin protection associated with the regular use of ceramide-containing cream (CC) versus other creams (OC) for improving hand contact dermatitis. Methods: We performed a double-center randomized trial that enrolled workers with hand dermatitis. All workers received personalized training. The intervention was 3 times per day application of the study emollient. The control arm used an emollient of choice without ceramide, as needed. The primary outcome was improvement in hand dermatitis at 1 and 3 months of follow-up. Results: In total, 102 patients with hand dermatitis were enrolled in this study. Improvement in dermatitis was found in 40%, 52.5%, 50%, and 63% of OC and CC, at the first and second follow-ups, respectively. The use of CC was significantly associated with an improvement in dermatitis (odds ratios 2.6; 95% confidence intervals 1.30-5.2), analyzed using generalized equation estimation during the follow-up. Conclusion: Our study demonstrated that an educational personalized intervention could improve the signs and symptoms in patients with hand dermatitis, and the use of a CC resulted in a significantly better outcome during the 3 months of follow-up.

Measurement of transepidermal water loss, stratum corneum hydration and skin surface pH in occupational settings: A review

BACKGROUND

The skin provides a permeable barrier which may be impaired in occupational settings. Transepidermal water loss (TEWL), stratum corneum hydration (SCH) and skin surface pH (SSpH) have been used in occupational settings to predict early onset of occupational skin diseases, to measure the effectiveness of prevention strategies for occupational skin diseases, and to assess skin condition during exposure. The aim was to compare the findings, identify shortcomings in the methodology and data reporting and furthermore, to make recommendations for future studies.

MATERIALS AND METHODS

A literature study was conducted on studies published before December 2018 to provide a review on the measurement of TEWL, SCH and SSpH in occupational settings.

RESULTS

TEWL, SCH and SSpH were previously measured in a wide variety of industries. Results between studies were highly variable, due to different study designs and different anatomical positions measured. Not all of the measurement conditions were reported and variations in study objectives led to data being reported and interpreted differently for most studies.

CONCLUSION

Incomplete reporting of methodology hinders comparison of bioengineering measurements. No bioengineering method has been proven useful as a predictive tool for occupational skin diseases, however, it is useful in the acute assessment of skin condition. It is recommended that future studies on TEWL, SCH and SSpH adhere to guidelines for occupational settings as far as possible to enable comparison between studies.

Effectiveness of a skin care programme for the prevention of contact dermatitis in healthcare workers (the Healthy Hands Project): A single-centre, cluster randomized controlled trial

BACKGROUND

Healthcare workers (HCWs) are at risk of developing hand dermatitis (HD). Guidelines recommend moisturizers to prevent HD, but in practice their effectiveness has been poorly investigated.

OBJECTIVES

To assess whether an intervention aimed at improving skin care leads to a reduction in HD severity.

METHODS

In this 1-year randomized controlled trial, 9 wards (285 HCWs) were allocated to an intervention group (IG), and 10 wards (216 HCWs) were allocated to the control group (CG). The intervention included provision of cream dispensers with electronic monitoring of use, regularly communicated to the HCWs. The primary and secondary outcomes were change from baseline in Hand Eczema Severity Index (HECSI) score (ΔHECSI) and change in natural moisturizing factor (NMF) level (ΔNMF).

RESULTS

At 12 months, the rates of loss to follow-up were 41% and 39% in the IG and the CG, respectively. The HECSI score was reduced in the IG by -6.2 points (95%CI: -7.7 to -4.7) and in the CG by -4.2 points (95%CI: -6.0 to -2.4). There was no significant difference in ΔHECSI or ΔNMF between the groups. Relative improvement in the HECSI score was significantly higher in the IG than in the CG (56% vs 44%). In a subgroup of HCWs with mild HD, the IG showed a larger HECSI score decrease than the CG (P < 0.001).

CONCLUSION

Although there was no significant effect on the primary outcomes, the intervention showed overall positive effects on the HECSI score.

Interventions for preventing occupational irritant hand dermatitis

BACKGROUND

Occupational irritant hand dermatitis (OIHD) causes significant functional impairment, disruption of work, and discomfort in the working population. Different preventive measures such as protective gloves, barrier creams and moisturisers can be used, but it is not clear how effective these are. This is an update of a Cochrane review which was previously published in 2010.

OBJECTIVES

To assess the effects of primary preventive interventions and strategies (physical and behavioural) for preventing OIHD in healthy people (who have no hand dermatitis) who work in occupations where the skin is at risk of damage due to contact with water, detergents, chemicals or other irritants, or from wearing gloves.

SEARCH METHODS

We updated our searches of the following databases to January 2018: the Cochrane Skin Specialised Register, CENTRAL, MEDLlNE, and Embase. We also searched five trials registers and checked the bibliographies of included studies for further references to relevant trials. We handsearched two sets of conference proceedings.

SELECTION CRITERIA

We included parallel and cross-over randomised controlled trials (RCTs) which examined the effectiveness of barrier creams, moisturisers, gloves, or educational interventions compared to no intervention for the primary prevention of OIHD under field conditions.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by Cochrane. The primary outcomes were signs and symptoms of OIHD developed during the trials, and the frequency of treatment discontinuation due to adverse effects.

MAIN RESULTS

We included nine RCTs involving 2888 participants without occupational irritant hand dermatitis (OIHD) at baseline. Six studies, including 1533 participants, investigated the effects of barrier creams, moisturisers, or both. Three studies, including 1355 participants, assessed the effectiveness of skin protection education on the prevention of OIHD. No studies were eligible that investigated the effects of protective gloves. Among each type of intervention, there was heterogeneity concerning the criteria for assessing signs and symptoms of OIHD, the products, and the occupations. Selection bias, performance bias, and reporting bias were generally unclear across all studies. The risk of detection bias was low in five studies and high in one study. The risk of other biases was low in four studies and high in two studies.The eligible trials involved a variety of participants, including: metal workers exposed to cutting fluids, dye and print factory workers, gut cleaners in swine slaughterhouses, cleaners and kitchen workers, nurse apprentices, hospital employees handling irritants, and hairdressing apprentices. All studies were undertaken at the respective work places. Study duration ranged from four weeks to three years. The participants' ages ranged from 16 to 67 years.Meta-analyses for barrier creams, moisturisers, a combination of both barrier creams and moisturisers, or skin protection education showed imprecise effects favouring the intervention. Twenty-nine per cent of participants who applied barrier creams developed signs of OIHD, compared to 33% of the controls, so the risk may be slightly reduced with this measure (risk ratio (RR) 0.87, 95% confidence interval (CI) 0.72 to 1.06; 999 participants; 4 studies; low-quality evidence). However, this risk reduction may not be clinically important. There may be a clinically important protective effect with the use of moisturisers: in the intervention groups, 13% of participants developed symptoms of OIHD compared to 19% of the controls (RR 0.71, 95% CI 0.46 to 1.09; 507 participants; 3 studies; low-quality evidence). Likewise, there may be a clinically important protective effect from using a combination of barrier creams and moisturisers: 8% of participants in the intervention group developed signs of OIHD, compared to 13% of the controls (RR 0.68, 95% CI 0.33 to 1.42; 474 participants; 2 studies; low-quality evidence). We are uncertain whether skin protection education reduces the risk of developing signs of OIHD (RR 0.76, 95% CI 0.54 to 1.08; 1355 participants; 3 studies; very low-quality evidence). Twenty-one per cent of participants who received skin protection education developed signs of OIHD, compared to 28% of the controls.None of the studies addressed the frequency of treatment discontinuation due to adverse effects of the products directly. However, in three studies of barrier creams, the reasons for withdrawal from the studies were unrelated to adverse effects. Likewise, in one study of moisturisers plus barrier creams, and in one study of skin protection education, reasons for dropout were unrelated to adverse effects. The remaining studies (one to two in each comparison) reported dropouts without stating how many of them may have been due to adverse reactions to the interventions. We judged the quality of this evidence as moderate, due to the indirectness of the results. The investigated interventions to prevent OIHD probably cause few or no serious adverse effects.

AUTHORS' CONCLUSIONS

Moisturisers used alone or in combination with barrier creams may result in a clinically important protective effect, either in the long- or short-term, for the primary prevention of OIHD. Barrier creams alone may have slight protective effect, but this does not appear to be clinically important. The results for all of these comparisons were imprecise, and the low quality of the evidence means that our confidence in the effect estimates is limited. For skin protection education, the results varied substantially across the trials, the effect was imprecise, and the pooled risk reduction was not large enough to be clinically important. The very low quality of the evidence means that we are unsure as to whether skin protection education reduces the risk of developing OIHD. The interventions probably cause few or no serious adverse effects.We conclude that at present there is insufficient evidence to confidently assess the effectiveness of interventions used in the primary prevention of OIHD. This does not necessarily mean that current measures are ineffective. Even though the update of this review included larger studies of reasonable quality, there is still a need for trials which apply standardised measures for the detection of OIHD in order to determine the effectiveness of the different prevention strategies.

The three moments of skin cream application: an evidence-based proposal for use of skin creams in the prevention of irritant contact dermatitis in the workplace

Contact dermatitis is one of the most common occupational diseases, with serious impact on quality of life, lost days at work and a condition that may be chronically relapsing. Regular prophylactic skin cream application is widely acknowledged to be an effective prevention strategy against occupational contact dermatitis; however, compliance rates remain low. To present a simple programme for skin cream application in the workplace with focus on implementation to drive down the rate of occupational irritant contact dermatitis, an expert panel of eight international dermatologists combined personal experience with extensive literature review. The recommendations are based on clinical experience as supported by evidence-based data from interventional studies. The authors identified three moments for skin cream application in the work place: (i) before starting a work period; (ii) after washing hands; and (iii) after work. Affecting behaviour change requires systematic communications, monitoring and reporting, which is proposed through Kotter's principles of organizational change management. Measurement tools are provided in the appendix. Interventional data based on application of this proposal is required to demonstrate its effectiveness.

Clinical Effectiveness of Moisturizers in Atopic Dermatitis and Related Disorders: A Systematic Review

BACKGROUND

Moisturizers are widely used for atopic dermatitis (AD) and related conditions, but available evidence of their effectiveness has not been reviewed in a systematic fashion.

OBJECTIVES

Our objective was to investigate the effectiveness of emollients, as a group and individually, in the treatment of AD and related conditions, by means of a systematic review.

DATA SOURCES

Studies indexed in MEDLINE and/or Embase before 16 January 2015.

STUDY ELIGIBILITY CRITERIA

Controlled clinical studies comparing the clinical effect of a moisturizer against its vehicle, another moisturizer, or no treatment were eligible. For the outcomes transepidermal water loss (TEWL) and stratum corneum hydration, uncontrolled before-after designs were also eligible.

PARTICIPANTS

Participants were patients with AD, irritant hand dermatitis, and/or ichthyosis vulgaris.

RESULTS

Out of the 595 publications initially identified, 45 (48 studies, 3262 patients) were eligible for inclusion. A vast majority of studies indicate that moisturizers have beneficial effects on clinical symptoms [SCORAD (SCORing Atopic Dermatitis) reductions ranging from 0 to 2.7 points], TEWL (range 0 to -12.2 g/m(2)h) and stratum corneum hydration (range +8 to +100%). Direct comparisons between individual moisturizers are still scarce, but the clinical effect appears to be much more well-documented for urea and glycerin than, for example, propylene glycol, lactate, ceramide, and aluminum chlorohydrate. Compared with urea studies, glycerin studies were more often associated with a high risk of bias.

LIMITATIONS

Due to differences in study designs and outcome measures, a quantitative meta-analytic approach was not deemed feasible, and formal indicators of publication bias such as funnel plots could not be used. However, a large number of moderately sized studies with positive outcomes could be compatible with selective publishing of favourable results.

CONCLUSIONS

The clinical effect of moisturizers is well-documented. Urea-based preparations may be preferable as a first-line treatment, but there is an unmet need for well-powered comparisons between individual moisturizers.

International guidelines for the in vivo assessment of skin properties in non-clinical settings: Part 2. transepidermal water loss and skin hydration

BACKGROUND

There is an emerging perspective that it is not sufficient to just assess skin exposure to physical and chemical stressors in workplaces, but that it is also important to assess the condition, i.e. skin barrier function of the exposed skin at the time of exposure. The workplace environment, representing a non-clinical environment, can be highly variable and difficult to control, thereby presenting unique measurement challenges not typically encountered in clinical settings.

METHODS

An expert working group convened a workshop as part of the 5th International Conference on Occupational and Environmental Exposure of Skin to Chemicals (OEESC) to develop basic guidelines and best practices (based on existing clinical guidelines, published data, and own experiences) for the in vivo measurement of transepidermal water loss (TEWL) and skin hydration in non-clinical settings with specific reference to the workplace as a worst-case scenario.

RESULTS

Key elements of these guidelines are: (i) to minimize or recognize, to the extent feasible, the influences of relevant endogenous-, exogenous-, environmental- and measurement/instrumentation-related factors; (ii) to measure TEWL with a closed-chamber type instrument; (iii) report results as a difference or percent change (rather than absolute values); and (iv) accurately report any notable deviations from this guidelines.

CONCLUSION

It is anticipated that these guidelines will promote consistent data reporting, which will facilitate inter-comparison of study results.

Interventions for preventing occupational irritant hand dermatitis

BACKGROUND

Occupational irritant hand dermatitis (OIHD) is an important cause of discomfort in the working population. Different preventive measures are in place but it is not clear how effective these are.

OBJECTIVES

To assess the effect of interventions for preventing OIHD in healthy people who work in occupations where the skin is at risk of damage.

SEARCH STRATEGY

In May 2010, we searched the Cochrane Skin Group Specialised Register, the Cochrane Central Register of Controlled Trials in The Cochrane Library, MEDLlNE and EMBASE. Conference proceedings, and ongoing trials registers were also searched.

SELECTION CRITERIA

Randomised controlled trials (RCTs) studying the effectiveness of barrier creams, moisturisers, gloves, complex educational interventions, and other interventions for the prevention of OIHD.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the trials and extracted data.

MAIN RESULTS

Four RCTs involving 894 participants from different occupations were included. The primary outcome was numbers of new cases.One large RCT of 708 print and dye workers compared 2 barrier creams (containing silicone or hydrocarbon) versus no intervention. Fewer workers using barrier creams developed OIHD than those who did not (39.9% versus 45%, (OR 0.75, 95% CI 0.53 to 1.07. P = 0.11) but this was not statistically significant.In 1 RCT of 54 metal workers less developed OIHD when using an after work emollient or a barrier cream compared to no intervention. There was no statistical difference between the groups at different times of follow-up.One RCT of 111 cleaners and kitchen workers compared a moisturiser (Locobase) versus no intervention using a cross-over design. While using the moisturiser no participant developed OIHD. During the control period with no skin treatment, 19 (20.4%) out of 93 participants developed OIHD.One RCT of 21 hairdressers compared a barrier cream containing aluminium chlorohydrate (Excipial protect) versus its vehicle. No participant developed OIHD while the products were used.Only limited side-effects such as transient itching, stinging, and dryness were reported for the interventions.

AUTHORS' CONCLUSIONS

Although the findings of this review were generally positive, no statistical significance was reached. We conclude that at present there is insufficient evidence for the effectiveness of most of the interventions used in the primary prevention of OIHD. This does not mean that current measures are necessarily ineffective, as the limited studies to date have been rather small and of poor quality. Larger well designed RCTs are now needed in different workplaces to establish the effectiveness of various preventative strategies.

A double-blind, randomized study to assess the effectiveness of different moisturizers in preventing dermatitis induced by hand washing to simulate healthcare use

BACKGROUND

Healthcare-associated infection is an important worldwide problem that could be reduced by better hand hygiene practice. However, irritant contact dermatitis of the hands as a result of repeated hand washing is a potential complication that may be preventable by the regular use of an emollient.

OBJECTIVES

To assess the effect of moisturizer application after repeated hand washing (15 times daily) vs. soap alone.

METHODS

In a double-blind, randomized study, the effect of five different moisturizers on skin barrier function was determined by assessment after repeated hand washing over a 2-week period in healthy adult volunteers. Assessments of transepidermal water loss (TEWL), epidermal hydration and a visual assessment using the Hand Eczema Severity Index (HECSI) were made at days 0, 7 and 14.

RESULTS

In total, 132 patients were enrolled into the study. A statistically significant worsening of the clinical condition of the skin as measured by HECSI was seen from baseline to day 14 (P = 0.003) in those subjects repeatedly washing their hands with soap without subsequent application of moisturizer. No change was seen in the groups using moisturizer. Subclinical assessment of epidermal hydration as a measure of skin barrier function showed significant increases from baseline to day 14 after the use of three of the five moisturizing products (P = 0.041, 0.001 and 0.009). Three of the five moisturizers tested led to a statistically significant decrease in TEWL at day 7 of repeated hand washing. This effect was sustained for one moisturizing product at day 14 of hand washing (P = 0.044).

CONCLUSIONS

These results support the view that the regular application of moisturizers to normal skin offers a protective effect against repeated exposure to irritants, with no evidence of a reduction in barrier efficiency allowing the easier permeation of irritant substances into the skin as has been suggested by other studies. Regular use of emollient in the healthcare environment may prevent the development of dermatitis.

Individual susceptibility to occupational contact dermatitis

Occupational Contact Dermatitis (OCD) is one of the most common work-related diseases. High risk occupations are in health care, hairdressing, food sector and metal industry. OCD tends to become chronic; persistent OCD often results in impaired quality of life and loss of work ability. The purpose of this article is to review the present knowledge on the factors which determine individual susceptibility to acquire OCD. Recent discoveries regarding genes involved in the skin barrier, inflammatory response and biotransformation of xenobiotics provide more insight in the individual susceptibility for OCD. Knowledge of the factors which predispose to OCD is useful in occupational health practice for the application of preventive measures and for career guidance for apprentices and workers in high risk occupations.

Effectiveness of skin protection measures in prevention of occupational hand eczema: results of a prospective randomized controlled trial over a follow-up period of 1 year

BACKGROUND

We recently found a very low adherence to a generally recommended skin protection regimen in a sample of 1355 metalworkers.

OBJECTIVES

The present study assessed the effectiveness of skin protection as presently recommended, especially the differential contribution of skin care and skin protection, to the prevention of occupational hand eczema. Methods Of 1355 metalworkers screened, 1020 male volunteers, all fit for work, were recruited for a prospective intervention study with four arms (skin care, skin protection, both combined, and control group, i.e. no recommendation). The study was performed from winter 2006/2007 to spring 2008, following each subject for up for 12 months. Both hands were examined using a quantitative skin score, and a standardized personal interview was performed three times. The change of the objective skin score from baseline to 12 months was used as primary outcome measure.

RESULTS

After 12 months 800 subjects were included (78.4% of those recruited). The compliance to follow the randomized measure depended on the recommended measure and ranged from 73.7% to 88.7%. While in the control group a significant deterioration was found, the largest and significant improvement was noted in the group following the generally recommended skin protection programme (skin care + skin protection) followed by skin protection alone as second best.

CONCLUSIONS

The generally recommended skin protection regimen seems to provide effective prevention of occupational skin disease. Therefore, the compliance to follow the skin protection regimen, especially the use of skin protection, should be enhanced.

Effectiveness of skin protection creams in the prevention of occupational dermatitis: results of a randomized, controlled trial

OBJECTIVES

The aim of the trial was to investigate whether the publicized effects of skin protection creams can be replicated in a real occupational setting during activities that expose the skin.

METHODS

A prospective, randomized, four-tailed controlled pilot trial was performed to compare the effect of skin protection and skin care alone or in combination with cleansing against a control group (only cleansing). Two branches were selected for the investigation: the building industry and the timber industry. A total of 1,006 workers from these two branches were recruited, and out of these 485 workers were examined longitudinally for at least three time points over 1 year (lost for follow-up: 430 workers, exclusion: 91 workers). At each time point, as a primary outcome measure, we assessed the condition of the skin at both hands in a blinded manner and the individual was assigned to one of the following categories: no eczema, mild, moderate and severe eczema. As a secondary outcome measure, the worker's transepidermal water loss (TEWL) was measured under standardized conditions at the back of both hands. In addition, the workers were asked to evaluate their skin condition during the study.

RESULTS

With regard to differences in the occurrence of eczemas, we found only in workers in building industry without application of skin protection or skin care creams a statistical significant increase in the incidence between the first and the second visit and a statistical significant decrease in the incidence between the second and third visit. When evaluating the secondary outcome-measurement changes in the TEWL values, an improvement was found for the group skin protection and skin care in combination and by skin care alone. Females in the timber industry started with better TEWL values than males, which may be due to better overall skin care. In this group we found an improvement for the group skin protection and skin care in combination and by skin protection alone. For skin protection alone, we noted a slight, but not significant improvement in all other groups. The subjective improvement of skin condition was reported from the participants who used skin protection and skin care in combination.

CONCLUSIONS

Taking all these secondary-outcome measurements together, the main result of this study was that skin protection creams alone have a small effect on the skin barrier in workers in the building and timber industries compared with skin care alone or in combination with skin protection.

A systematic review of contact dermatitis treatment and prevention

BACKGROUND

Contact dermatitis (CD) is a common occupational disease. There have been no systematic reviews of CD treatment or prevention.

METHODS

Multiple databases were systematically searched. Using independent double review and published quality review criteria, articles were rated as good, fair, or poor. Treatment benefit data were tabulated and conclusions were based on the rated strength of published evidence.

RESULTS

In all, 49 studies met inclusion criteria. Barrier creams containing dimethicone or perfluoropolyethers, cotton liners, and softened fabrics prevent irritant CD. Lipid-rich moisturizers both prevent and treat irritant CD. Topical skin protectant and quaternium 18 bentonite (organoclay) prevent rhus dermatitis. Diethylenetriamine pentaacetic acid (chelator) cream prevents nickel, chrome, and copper dermatitis. Potent or moderately potent steroids effectively treat allergic CD. There were no macrolide immunomodulator trials that met inclusion criteria. This review did not include studies of children, animals, or non-English language publications.

CONCLUSIONS

A limited number of interventions effectively prevent or treat irritant and allergic CD, but well-controlled, outcome-blinded studies, particularly in the area of allergic CD prevention are needed.

Intra-individual variation of irritant threshold and relationship to transepidermal water loss measurement of skin irritation

Irritant susceptibility studies have used either visual assessment or transepidermal water loss (TEWL) to determine subject response. We have developed a visual assessment method which determines subject irritant threshold. We examined the relationship between sodium lauryl sulfate (SLS) irritant threshold and TEWL measurements from normal skin and SLS patch tests. 19 subjects were recruited. The irritant threshold of each subject was measured and TEWL measurements made from the applied SLS patch tests. Individuals with a lower irritant threshold (easily irritated skin) had elevated TEWL levels compared to those with higher thresholds. The irritant threshold test had a low intraindividual variation. This study showed that the 2 methods grouped patients in a similar manner. The variation seen may reflect the different outcomes measured: irritant threshold visually assesses the skin inflammatory response while TEWL measures skin barrier modification.

Prediction of irritancy in the human skin irritancy model and occupational setting

It is of great importance to find ways to lower the incidence of chronic irritant contact dermatitis. In this process, it is crucial to have insight in the factors that can predict irritancy. This review offers a survey of recent findings in the field of skin irritancy testing, discussed in the context of renowned, older work. Extrinsic and intrinsic factors that may determine the outcome of irritancy testing in the human skin model are considered. In recent decades, there has been increasing interest in factors influencing the development of occupational dermatitis by means of prospective cohort studies. This promising new area of investigation is discussed separately.

Occupational skin-disease data in Europe

The different occupational health systems and legislations in the countries across Europe makes it difficult for one to sketch a detailed picture for the whole continent. Reporting bias and selection bias have a considerable impact on the perceived prevalence and incidence, while reliable data are hard to extract from official registries. Data from one region in Germany will serve as an example. Comparison with data from other sources yields an estimate of 0.7 to 1.5 cases per 1,000 per year as a gross average, while the problem in specific occupational groups is more pronounced. Reliable data on social and economic impact are very scarce.

Problems with trials and intervention studies on barrier creams and emollients at the workplace

The potential effect of barrier creams or emollients in the prevention of work-related hand eczema has mostly been documented in a laboratory setting on experimentally damaged skin. Publications on real intervention studies of barrier creams or emollients in a workplace setting are scarce: only four such studies could be identified. The relatively short follow-up of most studies, and the small numbers of subjects enrolled, may reflect the organisational complexity of such studies. The observed effect is a combination of the intervention effect to be measured, and a number of disturbing variables. These disturbing variables are not just measurement error, but also phenomena such as the course of the disease, confounding and effect modification. In hand-eczema studies, the outcome parameters that should form the basis of the intervention effect are ill defined. Moreover, the study itself (i.e. the investigators) influences the results because there is rarely a single intervention: unknowingly, there are improvements in glove wearing, hand-washing habits or occupational hygiene in general. The performance of a blind study is often difficult or impossible. Large numbers of subjects have to be enrolled if a meaningful reduction in incidence of hand eczema is to be detected. One can demonstrate this by calculating the required enrollment in a study among employees in a nursing home.

Skin-conditioning products in occupational dermatology

Moisturizers are frequently used in the prevention of occupational contact dermatitis. This review discusses their chemistry and mode of action. Methods to prove their preventive efficacy are presented. In addition to pharmacological efficacy, subjective factors that influence application of the products and compliance come into play. In conclusion, moisturizers are only one element of skin-disease prevention at the workplace that should be viewed as a complex, inter-dependent system. The efficacy of the complete, integrated system of occupational skin care has to be proven.

Effectiveness of skin protection creams as a preventive measure in occupational dermatitis: a critical update according to criteria of evidence-based medicine

OBJECTIVES

This study attempts to assess the evidence of the generally recommended three-step programme of skin protection in the prevention of occupational skin disease.

METHODS

The following clinical questions, representative of critical appraisal of this preventive measurement, were generated: (1) Can a skincare regimen effectively reduce or eliminate work-related poor skin conditions? (2) Do protective creams prevent harmful substances from penetrating and adhering to the skin? (3) Is the differentiation between pre-exposure and post-exposure products justified by reliable data? Answers were generated according to the method used in evidence-based medicine by searching the literature, critically appraising the results and applying the results to the clinical questions. For our search we decided to use PubMed as the most convenient access to Medline and because, in contrast to other databases, this access is available free of charge.

RESULTS

To investigate the efficacy of barrier creams as pre-exposure skin protectors various in vitro and in vivo test methods have been developed. Over the past years the test techniques have been improved in order to adopt a real workplace situation. Efforts for standardisation of evaluation criteria have been made, too. Nevertheless, there is a lack of placebo-controlled, randomised clinical trials evaluating the benefit of these products in the prevention of occupational contact dermatitis under real workplace conditions. The literature data are conflicting; some publications report on the positive aspects of skin protection, whereas others stress the negative ones.

CONCLUSION

Not enough data have been accumulated for one to prove the benefit of skin protection measures under real workplace condition. Up to now, it is almost unclear if the various in vitro and in vivo methods used are suitable to simulate real workplace conditions and if these test results can be related to real occupational exposure. For the evidence-based recommendation of skin protection, further studies, especially under daily working conditions evaluating the contribution of each single element of skincare programme (products, frequency of application and education programme) are needed.

Skin protection programmes

Educational programmes, including evidence-based recommendations on skin protection (skin protection programmes), have been proposed for the prevention of irritant contact dermatitis in occupations with a high frequency of this disease. Recent intervention studies directed at wet-work employees showed a positive influence on wet-work behaviour and on clinical skin symptoms. The structure and implementation of skin protection programmes are discussed.

Barrier creams - skin protectants: can you protect skin?

Barrier creams (BC) are used in hand care to protect the user against damage from surfactants and other irritants; their clinical value remains debatable; some reports indicate that inappropriate BC application might induce a deleterious rather than a beneficial effect. Since many cosmetic formulations contain 'skin protectants', we review concept, application, and efficacy from the pertinent scientific literature.

Occupational irritant and allergic contact dermatitis among healthcare workers

Contact dermatitis is the most frequent occupational dermatosis and non-specific irritants in addition to specific Type IV sensitization are involved. We reviewed our database for data from 1994 to 1998 and selected 360 consecutive patients working in healthcare environments and experiencing contact dermatitis at their hands, wrists and forearms. We found that allergic contact dermatitis and irritant contact dermatitis were considered to be work-related in 16.5% (72/436) and 44.4% (194/436) of diagnoses, respectively. Occupational irritant contact dermatitis is due to exposure to a wide range of irritants in the workplace, such as soaps, solvents, cleansers and protective gloves, which conspire to remove the surface lipid layer and/or produce cellular damage. In this study the major relevant aetiological agents that induced occupational allergic contact dermatitis were: nickel sulphate (41 patch positivities), components of disinfectants [glutaraldehyde (5) and benzalkonium chloride (7)] and rubber chemicals [thiuram mix (15), carba mix (9) and tetramethylthiuram monosulphide (6)]. The best treatment for allergic contact dermatitis is to avoid those allergens causing the rash. Whenever this is not possible, contact with them needs to be reduced using properly selected protective gloves. Finally, subjects with atopic dermatitis should avoid 'wet work' and contact with irritants, because atopic dermatitis is significantly associated with irritant contact dermatitis.

Guidelines for care of contact dermatitis

These guidelines for the management of contact dermatitis have been prepared for dermatologists on behalf of the British Association of Dermatologists. They present evidence-based guidance for treatment, with identification of the strength of evidence available at the time of preparation of the guidelines, including details of relevant epidemiological aspects, diagnosis and investigation.

The efficacy of a protective cream in a real-world apprentice hairdresser environment

The object of this study was to compare the protective action of a new barrier cream (Excipial Protect, Spirig Pharma AG, Egerkingen, Switzerland) to its vehicle in the context of hand irritation of apprentice hairdressers caused by repeated shampooing and exposure to hair-care products. This was a double-blind cross-over comparing Excipial Protect (containing aluminium chlorohydrate 5% as active ingredient) against its vehicle alone. The efficacy of the creams was evaluated taking into account: (1) clinical scores by researchers, (2) biometric measurements, (3) subjective opinions of the subjects. An analysis of variance was performed considering order of application, degree of atopy, and reported number of shampoos. We observed very little difference in efficacy between the protective cream and its vehicle. The presence, however, of aluminium chlorhydrate in the protective cream was shown to have a positive effect against work-related irritation. The cosmetic qualities of the creams seemed, to the participants, to be as important as their real protective and hydrating properties, an important factor in compliance issues.

Prevention of work-related skin problems in student auxiliary nurses: an intervention study

The present study was designed as an intervention study to investigate whether an educational programme was efficient in preventing work-related skin problems on the hands. 107 student auxiliary nurses (61 in the intervention group and 46 in the control group) were followed during the first 10 weeks of their initial practical training in county hospitals. The intervention group was given an educational programme before the practical training started. For evaluation the participants had questionnaires, clinical examination of the hands, measurement of transepidermal water loss (TEWL) and patch testing. The use of hand disinfectants, which was discouraged in the educational programme, was significantly lower in the intervention group as compared to the control group (p=0.002). 48% of the intervention group and 58% of the control group had aggravation of skin problems during practical training (p>0.05). Use of hand disinfectant agents was significantly associated with aggravation of skin problems (p=0.016). A significant increase in TEWL for the control group (p<0.005), but not for the intervention group, was seen after 10 weeks of practical training. In conclusion, the present intervention study shows promising results from the use of an educational programme.

A cream containing the chelator DTPA (diethylenetriaminepenta-acetic acid) can prevent contact allergic reactions to metals

Chelating agents in protective barrier creams have often been used in the prevention of allergic contact dermatitis to nickel. In a pilot study, we demonstrated the preventive effect of 10% diethylenetriaminepentaacetic acid (DTPA) in an oil-in-water emulsion in nickel-sensitized patients. Now we reproduced these results in a randomized, double-blind study. Additionally, we investigated the efficacy of the barrier cream in other clinically relevant metal allergies. Individuals sensitized to various metals had a significant decrease in positive patch test reactions after pre-treatment with the DTPA-cream: 2.5% nickel sulfate (24/28 positive without pre-treatment versus 1/28 with pre-treatment; p<0.0001), 5% nickel sulfate (30/32 versus 15/32; p=0.0003), 1% cobalt chloride (19/20 versus 6/20; p=0.001) and 5% copper sulfate (13/14 versus 5/14; p=0.02). However, the cream had no protective effect with 1% palladium chloride (17/23 versus 16/23) and with 0.5% potassium dichromate (9/13 versus 7/13). We conclude that the DTPA-cream clearly abrogates positive patch test reactions in nickel-, cobalt- and copper-sensitized subjects and that it may therefore be helpful in the management of allergic contact dermatitis.

Effect of long-term use of moisturizer on skin hydration, barrier function and susceptibility to irritants

Moisturizers are often used in the prevention and treatment of irritant contact dermatitis. The present study was to determine whether long-term daily use of a moisturizer on normal skin would affect skin barrier function, hydration state, or susceptibility to sodium lauryl sulphate. Healthy volunteers used a moisturizer on one forearm 3 times daily for 4 weeks. The other forearm served as a control. Afterwards both forearms were challenged with a patch-test of sodium lauryl sulphate. Skin barrier function was evaluated by measuring trans-epidermal water loss and skin hydration by measuring electrical capacitance. Electrical capacitance was significantly increased on the treated arm during the treatment period. After challenge with sodium lauryl sulphate, transepidermal water loss was significantly higher on the arm treated with moisturizer than on the control arm. The results suggest that long-term treatment with moisturizers on normal skin may increase skin susceptibility to irritants.

Guidelines on sodium lauryl sulfate (SLS) exposure tests. A report from the Standardization Group of the European Society of Contact Dermatitis

This report reviews the clinical and histopathological reactions caused by sodium lauryl sulfate (SLS), and the non-invasive methods that can characterize these reactions. Furthermore, SLS exposure techniques and factors that may influence the outcome of these exposures are discussed. Finally, guidelines are introduced for each exposure technique in order to have a uniform approach to SLS testing in man. Since different study aims warrant different testing conditions, we have proposed 2 categories, namely susceptibility testing and provocative testing, tailored to the aim with which the study is performed.

The efficacy of different moisturizers on barrier recovery in hairless mice evaluated by non-invasive bioengineering methods. A model to select the potentially most effective product

Moisturizers (emollients) are used frequently on normal and diseased skin. However, only few studies have examined their effects in dynamic situations and in more clinically relevant settings. We evaluated the effect of 4 commonly used products in a hairless mice model after acute skin barrier perturbation with acetone. The efficacy was evaluated by measurement of the transepidermal water loss (TEWL) and electrical conductance at various time intervals during barrier repair. The test products were compared with acetone-treated air-exposed controls allowed to recover otherwise normally and with a known irritant product, chlorhexidine cream 1%. Locobase was the most effective product in correcting barrier function and significantly improved barrier function during early stages of barrier recovery (< 6 h) without interfering with late stages of barrier recovery (> 6 h). The irritant control product, chlorhexidine cream 1%, delayed barrier recovery in the late stages. The model makes it possible to evaluate the combined effects of exogenous and endogenous components on barrier repair and to select the potentially most effective products before performing more cumbersome and time-consuming field studies.

Predictive testing of metalworking fluids: a comparison of 2 cumulative human irritation models and correlation with epidemiological data

Metalworking fluids (MWF) have been reported as being an important cause of irritant contact dermatitis in metal workers. Our purpose was to determine whether the irritancy of different MWF assessed by 2 different types of predictive human in vivo tests could be compared with epidemiological data. 3 water-based MWF were tested in the same panel of subjects. Reactions were assessed by a visual score (VS), evaporimetry to evaluate the transepidermal water loss (TEWL) and chromametry to quantify erythema. Test 1: MWF were applied with Finn Chambers on the volunteers' mid-back, removed after 1 day of exposure, and reapplied for a further 2 days. Test 2: Cumulative irritant contact dermatitis was induced using a repetitive irritation test for 2 weeks (omitting weekends) for 6 h per day. We observed an increase in VS, TEWL, and erythema for all MWF, with the same irritancy ranking in both test models. Differentiation of the substances was better in the D1/D3 test. The experimental results partially correlated with the epidemiological data. Considering the shorter application time and the better discrimination of irritancy, we prefer the D1/D3 model as a predictive test of MWF irritancy. Our results might aid development of a standardized test to reduce cumulative skin irritation in metal workers.