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Query: UMLS:C0920652 (skin irritant)
 188 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect on the skin of menstrual pads containing sodium bicarbonate as a fragrance substitute and of sodium bicarbonate alone was studied in 50 healthy women. Skin changes were monitored by transepidermal water loss, capacitance, laser Doppler flowmetry, skin surface pH and visual scoring. No clinical signs developed after the volunteers had been patched with the menstrual pads for 24 hours. No subclinical vulvar skin irritant reactions were observed with bioengineering methods. The menstrual pads containing sodium bicarbonate as a deodorant did not significantly affect the vulva in short-term use.
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PMID:Evaluation of vulvar irritancy potential of a menstrual pad containing sodium bicarbonate in short-term application. 165 21

The effect of erythemogenic UVB irradiation and minimal erythemogenic concentration of sodium lauryl sulphate(SLS) 4% aqueous (a skin irritant) irritation, on skin water vapour loss (SVL) of 12 male Chinese volunteers was studied. The mean SVL rate of unirradiated/unirritated skin was 4.5(+/- 2.0) g water/m2/h. The mean rate for UVB irradiated skin was 6.2(+/- 3.9) g water/m2/h and the rate for SLS irritated skin was 38.5(+/ 22.3) g water/m2/h (p = 0.0003). The irritation index (defined as SVL rate of irradiated or irritated minus that of unirradiated/unirritated skin divided by SVL rate of unirradiated/unirritated skin) was significantly lower on UVB irradiated skin (0.4 +/- 0.5) than SLS irritated skin (8.1 +/- 4.2) (p = 0.0001). It appears that UVB irradiation has significant less effect on the skin barrier compared with SLS irritation. It appears that SVL measurement may be used to differentiate UVB induced erythema from irritant induced erythema.
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PMID:A comparison of the effect of UVB and sodium lauryl sulphate on skin water vapour loss. 322 37

2-Amino-3,5-dicyano-4-o-chlorophenyl-6-ethoxypyridine (ACCPE) is a water soluble compound formed during the alkaline treatment of the alcoholic liquor in the production of 2-chlorobenzylidene malononitrile (CS). The acute toxicity and primary irritancy of ACCPE and CS were investigated and compared. Both perorally and intravenously, ACCPE was significantly less acutely toxic than CS. Also, whilst CS was a moderate dermal and eye irritant, ACCPE was not a primary skin irritant and only marginally irritating to the eye. ACCPE presents a significantly lower acute handling hazard than does CS.
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PMID:Acute toxicity and primary irritancy of 2-amino-3,5-dicyano-4-o-chlorophenyl-6-ethoxypyridine. 393 60

An outbreak of dermatitis occurred among county jail inmates who removed dead fish from the Sacramento River in California after a spill of metam sodium. The spilled chemical decomposes to methylisothiocyanate (MITC), a known skin irritant. A retrospective cohort study was conducted among the inmates and their crew leaders. Among 42 jail group members, 27 had dermatitis involving the feet and ankles; dermatitis was associated with lower extremity water contact (RR = 3.4, 95% CI 1.0-11.8); the attack rate increased with length of time spent in the water. For comparison, other state and federal employees who worked in the river at the same time were also interviewed. None reported dermatitis. Over three-quarters (24/31) of these other clean-up workers whose feet became wet changed to dry clothing immediately; none of the jail group changed immediately. The river concentration of MITC measured 20-40 ppb at the time of exposure. We speculate that prolonged wetness, occlusive boots, friction, and heat contributed to chemical irritation at this low concentration; the experience of the other clean-up workers suggests that this outbreak could have been prevented.
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PMID:Irritant dermatitis among workers cleaning up a pesticide spill: California 1991. 779 24

The keratinocyte culture model has previously been used as an in vitro method for testing skin irritating potential of common skin irritants. However, solubility limits its use for finished products. Shampoo is very soluble in water which should make it an ideal product category for the cell culture model. To determine the skin irritant potential of several commercial shampoos, we employed cultured human keratinocytes as an in vitro model. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide test (MTT) and lactic dehydrogenase release (LDH) test were used to document cell toxicity. 7 volunteers were patch tested and their reactions evaluated using laser Doppler flowmetry and compared with the in vitro data. MTT and LDH have a good negative correlation with each other. Patch test reaction, especially at high concentrations, correlates relatively well with the in vitro test, especially with shampoos of strong and weak irritancy. However, the rank order of the shampoos of moderate toxicity was not the same as in the in vitro data. This suggests that the cell culture technique cannot directly replace in vivo methods, and that data obtained by the cell culture method should be interpreted carefully.
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PMID:Comparison of irritant potential of shampoos using cultured human epidermal keratinocytes model and patch test reaction measured by laser Doppler flowmetry. 818 17

In order to investigate the effect of occlusion on the skin, the flexor sides of both upper arms were covered with column-shaped with column-shaped closed chambers, 30 mm in outer diameter, 20 mm in inner diameter, and 5 mm in height, which were made of polyethylene foam. The tops of the chambers were sealed by plastic films with various levels of water vapor permeability to control moisture in each chamber. The raised chamber walls prevented direct contact between the skin and the plastic film. After 24 h of application, morphological changes of the skin surface were observed microscopically by the nitrocellulose-replica method. Although no visual alterations were found on all areas of occluded skin, microscopic evaluation showed that simple occlusion by films induced an increase in the number of deepened skin furrows on the skin surface. this increase was associated with lower water vapor permeability of the films, as well as with higher values of both temperature and humidity of the test day. Thus, since conditions which facilitate perspiration from the skin tend to cause skin irritation, prolonged exposure of the skin to sweat by simple occlusion may act as a primary skin irritant.
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PMID:Effect of occlusion on human skin. 865 72

Skin irritant reactions are under the control of a network of cytokines and lipid mediators. This study characterized the production of tumor necrosis factor-alpha (TNF) induced by a skin irritant treatment, tributyltin (TBT), in mice through transcription factor activation and its pharmacologic modulation by anti-inflammatory agents. The ears of BALB/c mice were painted with different amounts of TBT (67-536 nmol in acetone) or with acetone alone. At different times thereafter, TNF production was analyzed both at the mRNA and protein level, by semiquantitative RT-PCR and L929 cytotoxicity assay, respectively. TBT induced rapid (1 h) TNF gene expression and protein synthesis. Maximal TNF production was observed 2 h after treatment. The production of TNF was paralleled by accumulation of skin water; this was partially prevented by intraperitoneal injection of antibody against murine TNF. These data indicate that skin irritation induced by TBT is attributable, in addition to the actions of other inflammatory mediators, to the action of keratinocyte-derived TNF. TNF production was preceded by a rapid (5 min) activation of nuclear factor-kappaB (NF-kappaB), which was also maximal 30 min after treatment. TBT-induced accumulation of skin water and TNF production were significantly reduced by topical treatment with dexamethasone and pentamidine, two anti-inflammatory agents. Interestingly, dexamethasone, but not pentamidine, decreased TBT-induced NF-kappaB activation, confirming in vivo that the glucocorticoid receptor interacts functionally within the nucleus with other transcription factors opposing one another's activity.
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PMID:Induction of tumor necrosis factor-alpha in vivo by a skin irritant, tributyltin, through activation of transcription factors: its pharmacological modulation by anti-inflammatory drugs. 918 17

The murine local lymph node assay (LLNA) is a method for the predictive identification of chemicals that have a potential to cause skin sensitization. Activity is measured as a function of lymph node cell (LNC) proliferative responses stimulated by topical application of test chemicals. Those chemicals that induce a threefold or greater increase in LNC proliferation compared with concurrent vehicle controls are classified as skin sensitizers. In the present investigations we have evaluated further the reliability and accuracy of the LLNA. In the context of an international interlaboratory trial the sensitization potentials of six materials with a history of use in topical medicaments have been evaluated: benzoyl peroxide, hydroquinone, penicillin G, streptomycin sulfate, ethylenediamine dihydrochloride, and methyl salicylate. Each chemical was analyzed in the LLNA by all five laboratories. Either the standard LLNA protocol or minor modifications of it were used. Benzoyl peroxide and hydroquinone, both human contact allergens, elicited strong LLNA responses in each laboratory. Penicillin G, another material shown previously to cause allergic contact dermatitis in humans, was also positive in all laboratories. Streptomycin sulfate induced equivocal responses, in that this material provoked a positive LLNA response in only one of the five laboratories, and then only at the highest concentration tested. Ethylenediamine dihydrochloride dissolved in a 3:1 mixture of acetone with water, or in 4:1 acetone:olive oil (one laboratory), was uniformly negative. However, limited further testing with the free base of ethylene diamine yielded a positive LLNA response when applied in acetone:olive oil (AOO). Finally, methyl salicylate, a nonsensitizing skin irritant, was negative at all test concentrations in each laboratory. Collectively these data serve to confirm that the local lymph node assay is sufficiently robust to yield equivalent results when performed independently in separate laboratories and indicate also that the LLNA is of value in assessing the skin sensitization potential of topical medicaments.
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PMID:Assessment of the skin sensitization potential of topical medicaments using the local lymph node assay: an interlaboratory evaluation. 956 69

Protein kinase C (PKC) comprises a family of related phospholipid-dependent serine/threonine protein kinases. PKC is important in signal transduction, regulating cell proliferation and differentiation. Recently, it has also been suggested that PKC may play a part in the pathogenesis of contact dermatitis. However, the expression of PKC isoforms in the skin of mice with irritant contact dermatitis (ICD) has not been examined. In this study, ICD was induced in mouse skin by applying 5%, 10% and 20% sodium dodecyl sulphate (SDS) in Finn chambers on the backs of mice and fixing with surgical dressings for 24 h. Depending upon the SDS concentration, mild to strong skin irritant reactions were observed 24 h after removal of the irritant patches. The intensity of the reactions increased with the increasing concentration of SDS. PKC isoforms alpha, beta, gamma and delta were all detected in normal mouse skin by Western immunoblotting. The specificity of the PKC isoforms detected was identified further by competitive Western immunoblotting. Compared with normal mouse skin treated with double-distilled water, the levels of PKC isoforms alpha, beta, gamma and delta in the SDS-irritated mouse skin was decreased by 24.8-75.8%. These results suggest that, in SDS-ICD, mouse skin PKC isoforms alpha, beta, gamma and delta are down-regulated. The significance of this decrease is under further investigation.
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PMID:Protein kinase C isoform levels in normal and sodium dodecyl sulphate-irritated mouse skin. 976 42

Water is a skin irritant which deserves attention because of its ubiquity. During the Vietnam war, soldiers suffered from painful swollen feet, so-called tropical immersion foot. In occupational dermatology, the importance of water as a skin irritant is especially appreciated. The irritancy of water has been demonstrated by occlusion experiments; occlusion with either closed chambers or water-soaked patches has been shown to produce clinical and histopathological inflammation. Functional damage, as revealed by increased transepidermal water loss, has also been shown. Repeated water exposure without occlusion caused an increase in blood flow on irritated skin; however, clinical evaluation did not show a difference in dryness or scaling. Several mechanisms such as osmolarity, pH, hardness and temperature might account for the irritancy of water. Extraction or dilution of natural moisturizing factors in the stratum corneum is another possible explanation. Occlusion per se also changes the physiology of skin and may trigger the activation of potentially active substances. However, much remains to be done to clarify the risk factors and mechanisms of water-induced irritation.
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PMID:How irritant is water? An overview. 1061 10


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