Evaluation methods for sensitive skin / 中华皮肤科杂志

Compared with people with non-sensitive skin,people with sensitive skin are more likely to have some undesirable feelings and symptoms in response to stimuli from the external environment,such as itching and pain sensations,and even erythema after chemical stimulation of the skin.Few reviews are related to evaluation methods for sensitive skin in China and other countries.This review introduces subjective,semi-subjective and objective evaluation methods for sensitive skin,summarizes evaluation methods suitable for different types of sensitive skin,and analyzes advantages and limitations of various evaluation methods.

Effect of a tretinoin derivative ECPIRM on retinoic acid receptors and skin irritation responses to it in mice / 中华皮肤科杂志

Objective To estimate the effect of a tretinoin derivative ECPIRM on retinoic acid receptors (RARs),and to observe skin irritation responses to it in mice.Methods Cultured SCL-1 cells were divided into 2 groups to be treated with culture medium containing 10 μmol/L ECPIRM (ECPIRM group) or 10 μmol/L all-trans retinoic acid (ATRA) (ATRA group) for 24 hours,and those treated with drug-free culture medium served as the control group.Western blot analysis and real-time fluorescence-based quantitative PCR were performed to quantify the protein and mRNA expressions of RARs (RARα,RARβ,RARγ and RXRα) respectively.In addition,real-time fluorescence-based quantitative PCR was conducted to measure the mRNA expressions of two target genes of the activated RAR signaling pathway,i.e.,cytochrome P450 26A1 (CYP26A1) and tazarotene-induced gene 1 (TIG1).Eight BALB/c mice were equally divided into 2 groups to be topically treated with 0.075％ ECPIRM gel or 0.05％ ATRA cream at equal molar concentrations on the shaved skin once daily for 21 successive days.Skin irritation reactions were assessed in these mice.Results Compared with the control group,the ATRA group showed significantly increased protein and mRNA expressions of RARα,RARβ and RARγ (all P ＜ 0.05).The mRNA expressions of CYP26A1 and TIG1 genes in the ATRA group were 25.49 and 3.88 times that in the control group respectively (both P ＜ 0.01).However,there was no significant difference in the protein expressions of RARα,RARβ,RARγ and RXRα,or mRNA expressions of RARα,RARβ,RARγ CYP26A1 and TIG1 between the ECPIRM group and control group (all P ＞ 0.05).Obvious Skin irritation reactions such as erythema and desquamation were observed in BALB/c mice after 2-day topical treatment with ATRA cream,and their degree peaked after 5-day treatment.However,neither erythema nor desquamation was observed in BALB/c mice during 21-day treatment with 0.075％ ECPIRM gel.Conclusion Unlike ATRA,ECPIRM cannot activate the canonical RAR signaling pathway or cause skin irritation reactions.

Establishment of modified LLNA:BrdU-ELISA and its application in the safety evaluation of cosmetics / 中国比较医学杂志

Objective To establish a rapid modified Local lymph node assay ( LLNA) for the sensitization and irritancy potential of chemicals, and evaluate cosmetics products. Methods 3 kinds of chemicals ( 2 , 4-Dinitrochlorobenzene ( DNCB) , Eugenol and Hexyl cinnamic aldehyde) and 3 kinds of cosmetics were selected.The dorsal sides of both ears of female BALB/c mice were treated with 25μL/ear of the test solutions on 3 consecutive days, and the thickness of each ear was measured.BrdU solution was injected inter-peritoneally on day 5.On day 6, each auricle was weighed, the bilateral draining auricular lymph nodes were excised and weighed, then made into single cell suspension.BrdU was measured by ELISA using a commercial kit.Results Ear swelling and auricle weight of DNCB ( 1.0%) , Eugenol ( 25% and 50%) and number 3 cream foundation increased significantly ( P <0.05 or P <0.01), which may be considered as irritants.The others were negative.For LLNA, three chemicals and number 3 cream foundation pretended positive.Conclusion The combined LLNA/ear swelling/ear weight assay appears to be a reliable predictor of sensitization and irritancy potential, and is expected to play an important role in safety evaluation of cosmetics.

Larvicidal and irritant activities of hexane leaf extracts of Citrus sinensis against dengue vector Aedes aegypti L

Objective:To assess the larvicidal and irritant activities of the hexane extracts of leaves of Citrus sinensis (C. sinensis) against the early fourth instars and female adults of Aedes aegypti (Ae. aegypti). Methods: The larvicidal potential of the prepared leaf extract was evaluated against early fourth instar larvae of Ae. aegypti using WHO protocol. The mortality counts were made after 24 h and LC50 and LC90 values were calculated. The efficacy of extract as mosquito irritant was assessed by contact irritancy assays. Extract-impregnated paper was placed on a glass plate over which a perspex funnel with a hole on the top was kept inverted. Single female adult, 3-day old unfed/blood-fed, was released inside the funnel. After 3 min of acclimatization time, the time taken for the first take-off and total number of flights undertaken during 15 min were scored. Results: The citrus leaf extracts from hexane possessed moderate larvicidal efficiency against dengue vector. The bioassays resulted in an LC50 and LC90 value of 446.84 and 1 370.96 ppm, respectively after 24 h of exposure. However, the extracts were proved to be remarkable irritant against adults Ae. aegypti, more pronounced effects being observed on blood-fed females than unfed females. The extract-impregnated paper was thus proved to be 7-11 times more irritable as compared with the control paper. Conclusions:The hexane extracts from C. sinensis leaves are proved to be reasonably larvicidal but remarkably irritant against dengue vector. Further studies are needed to identify the possible role of extract as adulticide, oviposition deterrent and ovicidal agent. The isolation of active ingredient from the extract could help in formulating strategies for mosquito control.

Influences of routine-dose loratadine on the intensity of patch test reaction / 中华皮肤科杂志

ObjectiveTo investigate the influences of routine-dose loratadine on the positive patch test reaction to nickel sulfate.MethodsA double-blind,controlled and randomized study was carried out.A total of 121 patients with a positive patch test reaction to nickel sulfate were divided into two groups to receive loratadine 10 mg (experimental group,n =61 ) or placebo (control group,n =60) once daily for 14 days.The patch testing of nickel sulfate was performed on day 11,and clinical evaluation of the test was carried out on day 14 after the start of treatment.The intention to treat population was used for data analysis.ResultsNo changes were observed in the intensity of patch test reaction to nickel sulfate in 55 patients in the experimental group or 53 patients in the control group,and there was no significant difference between the two groups in the percentage of patients showing changes in the intensity of patch test reaction(9.8％ vs.11.7％,x2 =0.11,P ＞ 0.05).ConclusionThe routine-dose loratadine has no inhibitory effect on the intensity of skin patch test reaction to nickel sulfate.

Changes of three physiological parameters after subclinical skin irritation / 中华皮肤科杂志

Objective To evaluate the diagnostic significance oftransepidermal water loss (TEWL), skin capacitance (CAP) and skin surface pH in subclinical irritant dermatitis. Methods Thirty healthy females took part in the 8-day study. Four areas were delineated on the flexor side of both forearms of each subject: one area received no irritation and served as the control, one was challenged by 1% sodium lauryl sulphate (SLS), one by repeated tape stripping, and one by irradiation with 0.75 MED UVB. Irritations were continuously given for 5 days. Clinical evaluation was performed everyday before irritation. TEWL, CAP and skin surface pH were measured at baseline, on day 6, 7 and 8 after the first irritation. Results Clinical score maintained at 0 for all subjects through the 8-day study. After SLS irritation, TEWL was 3.17 ± 3.07 g/m2h on day 6, 3.32 ± 2.84 g/m2h on day 7 and 3.22 ± 2.36 g/m,Zh on day 8, and all were significantly higher than that on day 0 (0.40 ± 1.35 g/m2h, P < 0.01). Similarly, increased skin surface pH was observed on day 6, 7 and 8 after SLS irritation compared with that at baseline (all P < 0.05). On the contrast, CAP decreased on day 6, 7 and 8 after SLS irritation (all P < 0.05). After tape-stripping, a significant increase was observed in TEWL on day 6, 7 and 8 compared with that at baseline (2.54 ± 1.85 g/m2h, 2.40 ± 2.16 g/m2h and 2.17 ± 1.99 g/m2h vs 0.11 ± 1.10 g/m2h, all P < 0.01); significant increase of pH was noted only on day 8; meanwhile, there was no any significant change in CAP. UVB irradiation induced no obvious changes in any of these physiological parameters. Conclusions These three physiological parameters can be applied m the diagnosis of subclinical irritant contact dermatitis, and their diagnostic value varies with the pattern of irritation.

Evaluation of Cumulative Skin-irritation of Six Commercinlly Available Topical Retinoic Acid Preparations / 中华皮肤科杂志

Objective To evaluate the cumulative irritative effect of topical retinoic acid preparations on normal skin.Methods A randomlized,doubled blind,placebo-controlled clinical trial was carried out with7groups for6tested preparations.All subjects were patch tested with each preparation for24hours on Monday to Thursday,and for72hours on Friday.The patch tests were performed for3consecutive weeks.Results The minimal cumulative irritative effects were found in Group G treated with0.1%adapalene gel,with a cumulative irritative index of0.09?0.11in20days.The cumulative irritative index was significantly lower in Group G than that in Group B treated with0.1%retinoic acid(Diweishuang誖)(0.59?0.24),or in0.025%retinoic acid(Diweishuang誖)(0.41?0.22),or in0.05%retinoic acid(VITAMIN誖Cream)(0.25?0.22).Conclusion Adapalene,the third generation of retinoic acid,is characterized by lower irritative ef-fects in comparison to the first generation of topical retinoic acid agents.

Assessment of skin toxicity using living skin equivalents / 대한피부과학회지

BACKGROUND: There are various alternative in vitro irritancy tests for substituting animal experiment. However, there is no standardized method or guideline for assessing in vitro cytotoxicity. OBJECTIVES: In order to predict toxicity on human skin, an experimental model was evaluated for the cutaneous cytotoxicity using living skin equivalents(LSE). METHODS: After applying test substances (SLS, various plant extracts) on LSE, morphological examination and MTT reduction assay was done. RESULTS: The results showed that cytotoxicity of SLS using LSE was well correlated with the concentration of SLS. Furthermore, characteristic histologic findings were observed according to the increasing concentrations of test materials. CONCLUSION: These results showed that LSE can be used as an alternative model to replace animal model for cytotoxicity testing.

Evaluation of Cutaneous Irritancy Using Human Skin Recombinants / 대한피부과학회지

BACKGROUND: There is an increasing need for the development of in vitro models capable of substituting for animals in cutaneous irritancy studies. Until now, various culture models have been developed, including skin organ cultures, conventional and air-exposed cell cultures. The air-exposed culture forms a multilayered epidermis showing an overall structure which resembles that of a native epidermis. The presence of a coherent stratum corneum layer in these cultures permits the application of potential irritants at the concentrations and formulations which are applied in vivo. Recently, a new human skin recombinant, made of human keratinocytes cultured on de-epidermized dermis with fibroblast-populated collagen matrix, has been developed and appears to represent a better skin equivalent model than previous models. OBJECTIVE: In the present study, monolayer-cultured human keratinocytes and the new human skin recombinants were evaluated for the test models of various skin irritants. METHODS: The extent of skin irritancy induced after application of 3 different irritants (sodium lauryl sulfate, methyl paraben, and polyethylene glycol-400) was evaluated on the basis of (1) MTT assay, (2) neutral red uptake assay, (3) LDH release, and (4) release of IL-1 alpha. In the human skin recombinants, morphological perturbations and changes in the expression of differentiation-specific protein markers (keratin 1, involucrin, filaggrin, and loricrin) were also evaluated. To determine the difference between in vivo and in vitro models for the detection of irritancy, a patch test was performed on 11 normal human volunteers with various concentrations of the different irritants RESULTS: The results of the present study show that irritant cytotoxicity correlates well with irritant concentration in both monolayer-cultured human keratinocytes and the new human skin recombinant. The new human skin recombinant is superior to monolayer culture as an in vitro model for skin irritancy screening in that the concentrations of test irritants are the same as in vivo. With the human skin recombinant, morphological changes were observed according to the irritant concentration. CONCLUSION: The new human skin recombinant can be used as an alternative to animals for skin irritancy screening.

Twenty-one day cumulative irritancy study of 2 new hand and body lotions compared to a standard skin lotion

Thirty healthy Filipino subjects of both sexes with ages between 18 and 54 years underwent a modified Draize test in humans to determine Cumulative Irritancy Index for 21 cumulative days. Utilizings the Mean Cumulative Irritancy Index of less than 1 to indicate non-irritancy and a value of more than 1 to indicate irritancy, the experimental lotions 1 (0.68) and 2 (0.53), belonged to the non-irritant category, while lotion 3 (4.45) was considered irritant based on this classification. (Auth)

The Irritancy of Hand Dishwashing Liquids on the Skin

BACKGROUND: The regular use of soaps and synthetic detergents has been associated with skin dryness and aggravation of dermatological conditions. OBJECTIVE: Our purpose was to investigate the irritancy of 10 hand dishwashing liquids on normal skin. METHODS: The skin changes, responding to repeat patch testing with 10 hand dishwashing liquids, were measured by visual scoring. RESULTS: The results are summarized as follows; 1. Of the 16 healthy volunteers 8 had reactions. 5 women and 3 men, but there was no significant difference in irritancy between men and women. 2. The mean irritancy scores of the 10 hand dishwashing liquids ranged from 0.06 to 0.88. 3. A prominent increase in the degree of erythema in the first 24 hour patch test did not persist beyond exposure day 5, but after day 5, augmented responses of the erythema and scales, even fissuring occurred. 4. The pH of the test solutions of the hand dishwashing liquids ranged from 5.0 to 6.0, but there appeared to be no correlation between pH and irritancy in the dishwashing liquids tested. CONCLUSION: Our data suggests that regular exposure to hand dishwashing liquids may cause disturbances of the skin in a substantial proportion of individuals, and workers should use hand dishwashing liquids in lower concentrations than recommended and only for short periods with protective measures.

The Study on the Effect of Six Soaps on Cutaneous Irritation Measured by Noninvasive Technique / 대한피부과학회지

BACKGROUND: Soaps are the most widely used body cleanser and sometimes cause irritation of the skin. OBJECTIVE: Our purpose was to compare the skin irritancy of 6 soaps using noninvasive techniques. METHODS: The skin responses to patch test with 6 soaps were measured by visual scoring, evaporimeter and corneometer. RESULTS: The results are summarized as follows. 1. F soap was shown to cause the least irritancy measured by visual scoring and corneometer. But using evaporimeter, there were no differences in irritancy between the 6 soaps. 2. Through correlation analysis, we found that the evaluation of the evaporimeter was closely related to visual measurement. CONCLUSION: Soap irritancy can be measured by noninvasive techniques, such as the evaporimeter, corneometer, laser doppler flowmetry and visual scoring. Further study of evaluation after short and repeat contacts with soap are needed.

Skin Reactions Induced by Topical Retinoic Acid in Mice / 中华皮肤科杂志

Objective To investigate the skin reactions induced by to pical 0.1% tretinoin and its vehicle in mice.Methods 0.1% tretinoin and its v ehicle were applied separately on mice backs,once a day for 30 days.The skin r eactions,including erythema and scaling,were observed macroscopically and meas ured by biological instruments.Results Macroscopically the skin reactions of erythema and scaling induced by topical tretinoin occurred on day 3 after applic ation,reached its peak on day 6 and disappeared on day 12,and neither erythema nor abnormal scaling appeared in spite of continuing application until day 30.The erythema value measured was enhanced significantly on day 1 after applicatio n,reached its peak on day 6,maintained until day 9 and became normal on day 11.From then to day 30,it maintained at the normal level.The scaling value measu red enhanced significantly on day 3 after application,reached its peak on day 9 and became normal on day 27.Topical application of the vehicle induced neither skin reaction nor any change of erythema and scaling value.Conclusions Topic al application of 0.1% tretinoin induces skin reaction characterized by erythema and scaling.The reaction,transient but not related to the vehicle,experience s a process of "occurrence-peak-disappearance".