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

The authors summarized and analysed data on effects and usage of cutting fluids mixable with water in order to determine limits for rapid toxicologic and hygienic evaluation of these fluids if repeatedly cooled. Limitative characteristics are sensibilization and skin irritation caused by cutting fluids mixable with water. Synthetic compounds containing the fluids appeared carcinogenic and therefore require special attention.
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PMID:[Justifying the approaches to occupational regulation of water-mixable lubricant coolants]. 1034 23

It is important to have reliable methods for evaluation of skin barrier function when questions such as barrier perturbing effects of different agents and occlusive effects of different formulations are to be elucidated. A wealth of clinical work relates to measurements of transepidermal water loss in vivo, a method much affected by ambient air relative humidity, temperature, skin irritation processes, psychologic status of the subject, etc., factors that cause the method to suffer from low precision (i.e., high random error). Relating to these obstacles, we have developed a closed in vitro system for measurements of water diffusion rate through pieces of isolated stratum corneum at steady-state conditions, where the relative humidity and temperature is held constant and data can be collected continuously. Our evaporimeter-based in vitro system has a more than 3-fold higher precision (lower random error) ( approximately 10%) than measurements of transepidermal water loss in vivo ( approximately 35%). The results of our study show that: (i) the corneocyte envelopes contribute to the barrier capacity of stratum corneum; (ii) removal of the lipid intercellular matrix results in approximately a 3-fold increase in the water diffusion rate through the isolated stratum corneum (n = 20; p < 0.05), not a 100-fold as has previously been suggested; (iii) exposure to sodium dodecyl sulfate in water does neither alter the water diffusion rate (n = 10; p > 0.05) nor the water holding capacity (n = 10; p > 0.05) of stratum corneum; (iv) exposure to 1 M CaCl2 in water yields an increased water diffusion rate through stratum corneum (n = 10; p < 0.05); and (v) when applied to the stratum corneum in excess concentrations, the penetration enhancer Azone has occlusive effects on water diffusion through the stratum corneum (n = 6; p < 0.05).
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PMID:A new computer-based evaporimeter system for rapid and precise measurements of water diffusion through stratum corneum in vitro. 1050 37

Quercetin is a bioflavonoid with antioxidant and anti-inflammatory activity. The purpose of this study was to examine the effect of quercetin on acute skin irritation, with special interest in the skin barrier function recovery. Acute irritant contact dermatitis was induced in 15 patients by 24-h occlusion of 2% sodium lauryl sulfate (SLS) (day (D) 1). The influence of application on SLS-irritated skin of topical quercetin for 5 consecutive Ds, compared to vehicle and controls, was studied. Parameters measured were transepidermal water loss (TEWL) and erythema index. Final measurements were taken on D 7 after a 1-D rest period. TEWL and the erythema index continued to rise 2 D after application of SLS and 1 D after treatment with quercetin, vehicle or controls. Both TEWL and erythema values at D 7 did not return to values before the SLS barrier disruption at all the test sites. Therefore, quercetin topically applied after induction of irritant contact dermatitis does not appear to increase the recovery of barrier function and erythema caused by SLS.
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PMID:Effect of an antioxidant (quercetin) on sodium-lauryl-sulfate-induced skin irritation. 1070 30

The main goal of the present study was to investigate the response of the human skin equivalent Apligraf in vitro to the application of irritant substances and its predictivity as a screening tool for cumulative skin irritant potential in humans. Vaseline, calcipotriol, trans-retinoic acid, and sodium lauryl sulfate were applied to Apligraf in vitro for 24 h. Cell viability (lactate dehydrogenase leakage), release and mRNA expression of the proinflammatory cytokines IL-1alpha and IL-8, and morphological changes were assessed. The same products were applied to 30 healthy volunteers in a double-blind, randomized, vehicle-controlled within-subject study. The skin reactions after repeated 24-h applications over 3 weeks under Finn chamber patches were monitored by visual scoring and biophysical methods (trans-epidermal water loss, chromametry, and blood flow). Sodium lauryl sulfate was cytotoxic to Apligraf, and increased the release and expression of cytokines at low (0.2%, 0. 4%), but not at high (0.8%, 1%) concentrations. It induced severe irritancy in vivo. Trans-retinoic acid increased the expression and release of cytokines with no detectable cytotoxicity and showed moderate irritancy in humans. Although calcipotriol did neither affect cell viability nor the production of cytokines, it induced morphological signs of irritation and was mildly irritant for healthy volunteers. Vaseline was innocuous in vivo and induced no changes in Apligraf. In conclusion, the cumulative skin irritation potential of the tested products could be predicted with Apligraf in a sensitive and specific manner, by monitoring cytotoxicity, proinflammatory cytokines, and morphological changes.
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PMID:Use of human skin equivalent Apligraf for in vitro assessment of cumulative skin irritation potential of topical products. 1073 42

A structure-activity relationship (SAR) model has been developed to discriminate skin irritant from nonirritant esters. The model is based on the physicochemical properties of 42 esters that were tested in humans for skin irritation. Nineteen physicochemical parameters that represent transport, electronic, and steric properties were calculated for each chemical. Best subsets regression analysis indicated candidate models for further analysis. Regression analyses identified significant models (p < 0.05) that had variables that were also significant (p < 0.05). These candidate models were evaluated using linear discriminant analysis to determine if the irritant esters could be discriminated from nonirritant esters. The stability of the model was evident from the consistency of parameters among ten submodels generated using multiple random sampling of the database. The sensitivity of the ten models, evaluated by "leave-one-out" cross-validation, ranged from 0. 846 to 0.923, with a mean of 0.885 +/- 0.025 (95% CI). The specificity ranged from 0.615 to 0.923, with a mean of 0.738 +/- 0.06 (CI). Compared with nonirritant esters, irritant esters had lower density, lower water solubility, lower sum of partial positive charges, higher Hansen hydrogen bonding parameter, and higher Hansen dispersion parameter. The results indicate that physicochemical features of esters contribute to their ability to cause skin irritation in humans, and that chemical partitioning into the epidermis and intermolecular reactions are likely important components of the response. This model is applicable for prediction of human irritation of esters yet untested.
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PMID:A robust structure-activity relationship (SAR) model for esters that cause skin irritation in humans. 1078 76

The feasibility of the water-activated, pH-controlled silicone reservoir devices for transdermal administration was investigated using timolol maleate as a model drug. Timolol patches were applied to the arm of 12 volunteers for 81 h, two patches per subject. Timolol absorption from patches was compared to that from a peroral timolol tablet formulation (Blocanol((R)) 10 mg). Furthermore, in vivo plasma levels of timolol were compared with those predicted by kinetic simulations. Skin irritation induced by timolol patches was assessed by visual scoring and color reflectance measurements. With water-activated, pH-controlled patches both steady-state concentrations of timolol in plasma and its duration could be controlled. However, a considerable, inter-individual variability in the transdermal absorption of timolol was observed. This is due to the high fractional skin control in timolol delivery. Timolol patches were well tolerated by subjects. Skin irritation induced by the combination of timolol with long-term occlusion was mild, and after removal of the patches, skin changes were practically reversed in 24 h. Simulation model was useful in prediction of timolol levels in plasma after transdermal administration.
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PMID:Water-activated, pH-controlled patch in transdermal administration of timolol. II. Drug absorption and skin irritation. 1091 50

Surfactants are known to be skin irritants, but change in their irritant potential due to change in composition during handling and storage has not previously been investigated. The aim of this study was to investigate the influence of oxidation products on the irritant potential of a non-ionic ethoxylated alcohol, C12E5. Pure and oxidized C12E5 were tested, using 2 different patch test procedures; 1 with a single 24 h exposure and 1 with repeated exposures. 18 healthy volunteers participated in each of these studies. Evaluations were made by visual scoring and by measurement of transepidermal water loss and skin blood flow. In the single exposure study, no significant difference in skin irritation was observed between pure C12E5 and a sample of oxidized C12E5 at the concentrations tested (1, 3, 9 and 27%). After repeated exposures, however, the oxidized C12E5 was significantly more irritant than pure C12E5 at the concentrations 9% and 27% (p<0.05). Non-ionic ethoxylated surfactants are known for their weak skin irritant effect and are, due to this, often included in products with prolonged contact with the skin, i.e., skin care products. An increased irritant potential after oxidation might be of importance due to the conditions of use.
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PMID:Skin irritation from air-oxidized ethoxylated surfactants. 1094 46

In clinical practice, cutaneous exposure to a variety of irritants such as surfactants and solvents is frequent. Although the induction of irritant dermatitis by single irritants has been extensively studied in recent years, our knowledge of the effects of simultaneous application of different irritants is limited. Using non-invasive techniques for measurements of transepidermal water loss (TEWL) and skin colour reflectance, we quantified the irritant effects of single and concurrent application of 0.5% sodium lauryl sulphate (SLS) and undiluted toluene (TOL) in vivo. The irritants were applied twice daily for 30 min to the volar forearms of 20 volunteers. Repeated application of SLS and TOL induced an irritant reaction, as indicated by an increase in TEWL and skin redness. In contrast to SLS alone, the application of TOL alone induced only a moderate increase in TEWL, confirming previous results. Concurrent application of SLS/TOL and TOL/SLS induced significantly stronger reactions than those caused by twice daily application of each irritant on its own. Our results demonstrate that a mixed application of an anionic detergent and an organic solvent has an additive effect on skin irritation. It is suggested that pretreatment with SLS causes an increased susceptibility to TOL irritation and vice versa. Thus, the necessity for special precautions against skin absorption of TOL when handling detergents such as SLS is emphasized.
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PMID:Experimental irritant contact dermatitis due to cumulative epicutaneous exposure to sodium lauryl sulphate and toluene: single and concurrent application. 1097 28

In this questionnaire study, the authors compared the prevalence of certain symptoms and signs associated with Sick Building Syndrome and perceptions relative to environmental discomfort of employees in a central-air-conditioned dropping center and in natural-ventilation commercial shops located on the streets of Niteroi, Rio de Janeiro, Brazil. There was a statistically significant higher prevalence of symptoms (e.g., water and itching of eyes, sore throat, nose irritation, difficulty breathing, skin irritation, sneezing) that were characteristic of Sick Building Syndrome in the air-conditioned building than in the naturally ventilated stores. The results indicated that there exists a continuing need for further research in Brazilian work environments.
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PMID:Effect of ventilation systems on prevalence of symptoms associated with "sick buildings" in Brazilian commercial establishments. 1100 34

The notification procedure of the European Union (EU) for new chemicals requires the application of protocols on physicochemical and toxicological tests for the evaluation of physicochemical properties and probable toxic effects of each notified substance. A computerised database was developed from data sets and toxicological test protocols relating to substance properties responsible for skin and eye irritation/corrosion. To develop specific structure-activity relationship (SAR) models and to find rules for a decision support system (DSS) to predict local irritation/corrosion, physical property data, chemical structure data and toxicological data for approximately 1300 chemicals, each having a purity of 95% or more, were evaluated. The evaluation demonstrated that the lipid solubility and aqueous solubility of a chemical are relevant to, or - in some cases - responsible for, the observed local effects of a substance on the skins and eyes of rabbits. The octanol/water partition coefficient and the measured value of the surface tension of a saturated aqueous solution of the substance give additional information that permits the definition of detailed SAR algorithms that use measured solubility values. Data on melting points and vapour pressure can be used to assess the intensity and duration of local contact with a chemical. Considerations relating to the reactivity of a pure chemical can be based on molecular weight and the nature of the heteroatoms present. With respect to local lesions produced following contact with the skin and eyes of rabbits, the data evaluation revealed that no general "local irritation/corrosion potential" of a chemical can be defined. A variety of mechanisms are responsible for the formation of local lesions on the skin or in the eyes: serious lesions are produced by mechanisms different from those that cause moderate irritation in these organs. In order to develop a DSS that uses the information extracted from the database, chemical main groups were categorised on the basis of their empirical formulae, and rules were defined of the type IF (physicochemical property) A, THEN not (toxic) effect B, based on correlations between specific local effects and measured physicochemical values. Other rules of the type IF substructure A, THEN effect B were developed based on correlations between specific local effects and the submitted structural formulae. Reactive chemical substructures relevant to the formation of local lesions and rules for the prediction of the absence of any skin irritation potential were identified. Proposals are made relating to the development of alternatives to eye irritation testing with rabbits.
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PMID:Development of a decision support system for the introduction of alternative methods into local irritancy/corrosivity testing strategies. Creation of fundamental rules for a decision support system. 1109 65


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