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Query: UMLS:C0152030 (skin irritation)
 2,146 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The probability of simultaneous cutaneous exposure to surfactants and penetration enhancers could occur frequently during routine skin treatment. This study ascertains whether pre-exposure of skin to laurocapram would affect the penetration of a model surfactant, sodium lauryl sulfate (SLS). In vitro experiments with human skin were performed to compare the penetration of SLS after pretreatment with (1) different concentrations of laurocapram, (2) after repeated SLS treatments, (3) untreated controls, and (4) water-control. Pre-exposure to laurocapram enhanced penetration of SLS compared to all other treatments (p < 0.05). Since subsequent pre-exposure of skin to laurocapram increased SLS penetration, the chances of an elevated skin irritation reaction at the exposed site may therefore be possible. Pre-exposure of the skin with SLS did not increase the SLS flux values significantly, compared to the laurocapram pretreated skin. From these results it can be proposed that proper care and precautions may be necessary after exposure of skin to laurocapram and also to various other percutaneous enhancers. Further in vivo correlations are essential to define the clinical implications of this study, especially as related to irritant dermatitis.
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PMID:Effect of topical laurocapram (Azone) on the in vitro percutaneous permeation of sodium lauryl sulfate using human skin. 880 Feb 95

Besides visual evaluation, skin irritation induced by sodium lauryl sulfate (SLS) may be characterized by bioengineering measurements, such as skin colour reflectance, transepidermal water loss (TEWL) or hydration. Short application times or low concentrations of the irritant usually do not modify the visual aspect of the skin, and the measurements described above are unchanged or only slightly altered. We were looking for a suitable method to measure cutaneous changes not detectable by usual bioengineering procedures. Therefore these measurements were compared to those of dynamic function testing of the stratum corneum, namely sorption-desorption and moisture accumulation tests. Different concentrations of SLS (0.1%, 0.5%, 2.5%), application times (15 min, 24 h) and times of testing (1 h, 24 h after patch removal) were investigated on the ventral forearm of human subjects. When SLS was applied for a short period (15 min), 1 h after patch removal skin colour, TEWL and hydration were not modified, while increases in hygroscopicity, water-holding capacity and water accumulation were detected depending on the applied concentration. Increase of hygroscopicity was closely correlated with the alteration of epidermal barrier function (TEWL). We demonstrated that sorption-desorption and moisture accumulation tests performed on SLS-treated areas for a short period, without visible modifications, could evaluate changes of the stratum corneum properties. We consider these tests as useful complementary methods to skin colour, TEWL and hydration measurements, particularly in the detection of subclinical skin injuries.
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PMID:Measurement of sodium lauryl sulfate-induced skin irritation. 889 Oct 3

The human 4 hr patch test provides an opportunity to identify substances with significant skin irritation potential without recourse to the use of animals. To demonstrate the validity of the method it must be relevant and reliable. It is self-evident that the method is relevant to the identification of skin irritation hazards to humans. However, it is essential that the results be reproducible. This paper presents data on a number of substances tested by different laboratories. Eight substances were tested by two or more laboratories and the data compared with a standard positive control, 20% sodium dodecyl sulfate. In almost all cases, the outcome of this comparison was identical. Thus, despite the fact that there is known variability among human subjects in terms of skin reactivity to irritants, this simple method showed good reproducibility for the classification of acute skin irritation potential. Therefore, it is argued that this human 4-hr patch test is a valid alternative to the equivalent rabbit test for the assessment of skin irritation hazard to humans.
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PMID:Interlaboratory evaluation of a human patch test for the identification of skin irritation potential/hazard. 914 38

Exposure of the skin to sodium dodecyl sulfate (SDS) leads to disruption of barrier and skin irritation. We used repetitive short exposure to a low molarity SDS solution as an in vivo model to mimic the development of irritant contact dermatitis. In this model, we studied clinical (erythema), functional (transepidermal water loss(TEWL)) and cell biological changes. 24 healthy volunteers were patch tested with SDS (0.2%) for 4 h a day for 5 consecutive days. After removal of the patches, the exposed sites were treated 1 X daily either with a topical corticosteroid (triamcinolon acetonide cream 0.05%), a retinoid (tretinoin cream 0.025%), or a vitamin D3 derivative (calcipotriol ointment 50 micrograms/g). Irritant reactions were assessed by erythema scoring and measurement of barrier function with TEWL up to 14 days after the first challenge. Skin biopsies were taken for cell biological changes at day 4. Vehicle-treated sites served as controls. Repetitive exposure of human skin to SDS resulted in a gradual increase in erythema scoring and TEWL associated with the upregulation of proliferative cells as measured by the expression of Ki-67-antigen and of differentiation markers, visualized by increased expression of involucrin and epidermal-fatty-acid binding protein (E-FABP). Skin irritation as assessed by erythema scoring and TEWL was not significantly suppressed by triamcinolone cream. However, a significant reduction of the number of cycling keratinocytes and a decrease in involucrin positive cell layers was observed in this group. Neither treatment with calcipotriol ointment nor with tretinoin cream induced improvement of skin irritation as judged by visual scoring and TEWL. In contrast to steroid treatment, no significant effect of calcipotriol ointment or tretinoin cream treatment was observed with regard to the number of cycling cells and differentiation markers. Further studies are needed to assess whether treatment with topical corticosteroids is an effective modality in skin irritation and irritant contact dermatitis.
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PMID:Effect of a topical corticosteroid, a retinoid and a vitamin D3 derivative on sodium dodecyl sulphate induced skin irritation. 925 81

It has long been recognized that human skin can be subdivided into simple categories based on their sensitivity to sunlight--from Type I, never tans, always burns, to Type VI, marked constitutive pigmentation. There is also evidence that the more readily sunburnt type of skin is also more susceptible to the effect of irritants. In the present work, the irritancy threshold for sodium lauryl sulfate (SLS) has been assessed using a recently described 4-h acute skin irritation patch test. A total of 110 subjects covering all 6 skin types were examined and their threshold for acute irritancy defined as the lowest concentration of SLS, applied under 4-h occlusion, which would induce a clinically detectable irritant response. The SLS dose response generated using a range of concentrations (0.1%-20%) demonstrated that there was no significant difference between the groups under these test conditions. Even for Type VI skin (n = 25), the dose-response curve fell within the general pattern. These results reinforce the general applicability of predictions of acute irritant potential made in groups of human volunteers.
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PMID:Acute irritation thresholds in subjects with type I--type VI skin. 953 6

We have studied the effect of various detergents on keratinocyte gene expression in vitro, using an anionic detergent (sodium dodecyl sulfate), a cationic detergent cetyltrimethylammoniumbromide (CTAB), and two nonionic detergents, Nonidet P-40 and Tween-20. We measured the effect of these detergents on direct cellular toxicity (lactate dehydrogenase release), on the expression of markers for normal differentiation (cytokeratin 1 and involucrin expression), and on disturbed keratinocyte differentiation (SKALP) by northern blot analysis. As reported in other studies, large differences were noted in direct cellular toxicity. In a culture model that mimics normal epidermal differentiation we found that low concentrations of sodium dodecyl sulfate could induce the expression of SKALP, a proteinase inhibitor that is not normally expressed in human epidermis but is found in hyperproliferative skin. Sodium dodecyl sulfate caused upregulation of involucrin and downregulation of cytokeratin 1 expression, which is associated with the hyperproliferative/inflammatory epidermal phenotype found in psoriasis, wound healing, and skin irritation. These changes were not induced after treatment of cultures with CTAB, Triton X-100, and Nonidet-P40. This effect appeared to be specific for the class of anionic detergents because sodium dodecyl benzene sulfonate and sodium laurate also induced SKALP expression. These in vitro findings showed only a partial correlation with the potential of different detergents to induce clinical, biophysical, and cell biologic changes in vivo in human skin. Both sodium dodecyl sulfate and CTAB were found to cause induction and upregulation of SKALP and involucrin at low doses following a 24 h patch test, whereas high concentrations of Triton X-100 did not. Sodium dodecyl sulfate induced higher rates of transepidermal water loss, whereas CTAB treated skin showed more signs of cellular toxicity. We conclude that the action of anionic detergents on epidermal keratinocytes is qualitatively different from the other detergents tested, which might have implications for in vitro toxicology studies that use cell biologic parameters as a read-out. We would hypothesize that detergents cause skin injury by several mechanisms that include direct cellular toxicity, disruption of barrier function, and detergent specific effects on cellular differentiation, as demonstrated here for sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, and sodium laurate.
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PMID:Differential effects of detergents on keratinocyte gene expression. 954 Sep 75

No data are available on the irritant effect of nitroxide free radicals in human skin. Nitroxides are important biomedical skin probes used in Electron Paramagnetic Resonance spectroscopy and imaging. Our purpose was to study the skin irritation potential of different nitroxide free radical structures in skin of healthy human subjects. We investigated the following nitroxides: Tempo (2,2,6,6-tetramethyl-1-piperidinoxy), Doxo (2,2,5,5-tetramethyl-3-oxazolidinoxy), Proxo (2,2,5,5-tetramethyl- -dihydro-pyrrolinoxy), and Imidazo (2,2,3,4,5,5-hexamethyl-imidazoline-1-yloxyl). Cutaneous irritation was determined in human skin following a single application and after repetitive applications in comparison to the standardized irritant sodium lauryl sulfate (SLS). The response was evaluated clinically as well as by a bioengineering method analyzing transepidermal water loss (TEWL) and skin hydration (capacitance). The nitroxides were classified clinically from nonirritant (Imidazo, Proxo), to slightly irritant (Doxo, 100 mM), or moderately irritant (Tempo 100 mM) after a single application. The TEWL values were significantly increased by Doxo and Tempo, but capacitance values were not changed significantly. In the cumulative irritation test Tempo was scored as a slight irritant (10 mM). TOLH (2,2,6,6-tetramethyl-1-hydroxypiperidin), the hydroxylamine of Tempo, which is the major skin metabolite, did not cause skin irritation after a single or repetitive applications. This may indicate that a loss of cellular reducing equivalents may be involved in the inflammation process caused by Tempo. The order of nitroxide irritation potency (Tempo > Doxo >> Imidazo = Proxo) is inverse to the order of nitroxide biostability in human skin (Imidazo = Proxo >> Doxo > Tempo). In conclusion, nitroxide free radicals are classified as nonirritant to moderately irritant in human skin. Particularly, the pyrrolidine and imidazoline type nitroxides have a low potential to cause acute or subacute skin toxicity.
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PMID:Cutaneous tolerance to nitroxide free radicals in human skin. 955 76

A human 4-h patch test has recently been developed for testing the irritation hazard potential of chemicals. The original method was developed for comparative irritation assessments relative to benchmark irritants using simple statistical tests. In this context, the method has been shown to be robust in intralaboratory testing over time. Recent interlaboratory testing has also established the consistency of the method in assessment of the relative irritation potential of selected chemicals. These data help to position the method as a suitable replacement for animal test methods in assessment of skin irritation hazard. In addition, the method has great utility for investigating different parameters of clinical skin irritation. Using kinetic response patterns and curve fitting analysis, we have compared the relative irritation potential of chemicals in greater detail, using as a basis the time required for test subjects to respond as well as the incidence of positive responses. Also, using the response to 20% sodium dodecyl sulfate (SDS) as a benchmark, we've been able to examine the intersubject variation in clinical skin irritation responses. In general, subjects most reactive to 20% SDS, in terms of the exposure time required to produce a positive response, were relatively more sensitive to a 2nd irritant chemical as well. However, this was not an absolute correlation in that some test subjects showed divergent patterns of response. The method was also used to compare directly the relative skin reactivity of different populations, based on race (Caucasian versus Asian) or on neurosensory skin sensitivity. Our results using this acute exposure test method indicate little difference in visually assessed skin irritation among these diverse human subpopulations.
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PMID:Application of a 4-h human patch test method for comparative and investigative assessment of skin irritation. 956 90

Virtually all current detergent formulations contain mixtures of surfactants. Our experience and test data on these formulations, which is in agreement with that of many others, has shown that in use the formulations exhibit lower acute irritation potential than predicted by simple summation of the irritation potential of the individual actives. Using the criteria of the Dangerous Preparations Directive (EC Directive 88/379/EEC), many of these formulations classify as irritant in the neat state, with consequent labelling requirements. Such classification is based on addition of irritant components giving a total concentration which exceeds a nominal threshold. In this study, mixtures of surfactants were tested by application to a panel of 31 human volunteers for up to 4 hr, using the technique established for the assessment of acute skin irritation potential. The positive control, sodium dodecyl sulfate (SDS) at 20% concentration, gave an 84% positive response. Dimethyl dodecyl amido betaine (DDAB) at the same concentration gave a 94% response. However, a combination of 20% of each of these surfactants in the same panellists gave a response of only 44%--a significant reduction in the irritation potential. A further test conducted with a mixture of 10% SDS and 10% DDAB in a second panel gave a 31% positive response compared with a 94% positive response to the 20% SDS control in that panel. These results clearly demonstrate that the acute irritation potential of mixed surfactants cannot be predicted by simple summation of the irritation potential of the component substances. Initial results of the mechanistic investigation indicate that the reduced irritation induced by the mixed surfactant systems correlates with a reduced critical micelle concentration (CMC). However, the reduced CMC itself seems not to be responsible for the lowered irritation, since these experiments were conducted at concentrations well above the CMC. It is proposed that the critical event leading to skin irritation is binding to skin protein and that in mixed surfactant systems, the individual surfactants exhibit less affinity for this protein.
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PMID:Skin irritation potential of mixed surfactant systems. 960 95

A clinical study was performed to determine the effects of patch testing human skin with four industrially used surfactants on erythema formation, transepidermal water loss, and the contents in suction blister fluids of primary proinflammatory mediators including arachidonic acid, eicosanoids, and IL-1 alpha, which were analyzed by quantitative gas chromatography/negative ion chemical ionization mass spectrometry and by an enzyme-immunoassay, respectively. Benzalkonium chloride (BKCI) and sodium lauryl sulfate (SLS) elicited erythema and caused increased transepidermal water loss, indicating a disturbance of the epidermal barrier. Triethanolamine (TEA) and Tween 80 did not evoke these gross symptoms of inflammation. Suction blister fluids collected after a 24-h application of BKCl, SLS, and Tween 80 contained significantly increased amounts of individual eicosanoids whereas TEA induced no response. The induced eicosanoid profile was characteristic for each compound, pointing to different cell types of skin to be involved in their production. The elevation of prostaglandin and LTB4 contents correlated with the induction of erythema and the impairment of the epidermal barrier as shown for BKCl and SLS and preceded the maximum of erythema formation. IL-1 alpha contents did not correlate with these gross symptoms of inflammation. The results of this in vivo study support those of a previous study using human keratinocytes in culture indicating the release of arachidonic acid and prostaglandins to be an early event involved in the interaction of keratinocytes with surfactants. Moreover, the in vivo data with human skin underscore the mechanistic relationship to the in vitro model and support the concept that arachidonic acid and eicosanoid release from keratinocytes can be used as a marker of primary skin irritation.
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PMID:Arachidonic acid metabolism in primary irritant dermatitis produced by patch testing of human skin with surfactants. 987


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