PubMed Health⌕ Search

Biomedical subjects

R A Tupker

Publications and source records attributed to R A Tupker.

At least 19 recordsLinked to original sources
PubMed2003

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.

Dermatitis, Irritant↗
PubMed1999

Irritancy ranking of anionic detergents using one-time occlusive, repeated occlusive and repeated open tests.

Discrepancies between the one-time patch test and the wash test regarding the ranking of irritancy of detergents have been found in the literature. The aim of the present study was to investigate the concordance of irritancy rank order of 4 anionic detergents tested by 3 different exposure methods, namely one-time occlusive, repeated short-time occlusive and repeated short-time open tests. These detergents were sodium cocoyl isethionate (ISE), sodium lauryl sulfate (SLS), soap and disodium lauryl 3-ethoxysulfosuccinate (SUC). The reactions were evaluated by visual scoring and by transepidermal water loss (TEWL) measurement. When scored visually, the rank order in the one-time test was: SOAP > or = SLS > or = ISE > SUC. The other test methods yielded a different order: SLS > ISE > or = SOAP > SUC. A similar rank order was obtained with TEWL measurement for all exposure methods. Generally, the concordance among the different exposure methods was high when evaluated by TEWL. The concordance was lower when evaluation was performed by visual scoring. The present study demonstrates that the choice of exposure model and evaluation method may be important variables influencing the outcome of irritancy testing. It is proposed that the repeated open test is the best way to simulate most in-use situations where the uncovered skin is exposed to detergents. The repeated occlusive test or the one-time patch test may be better to simulate situations in which the skin is occluded after irritation by detergents.

Adolescent↗
PubMed1998

House-dust mite hypersensitivity, eczema, and other nonpulmonary manifestations of allergy.

The pathogenetic role of house-dust mites (HDM) in atopic dermatitis (AD) remains controversial, mainly because there is no common agreement on a provocation test that mimics ordinary exposure to HDM. This is related to the lack of knowledge of the mechanism of how HDM allergens enter the body. Theoretically, there are two possible routes: directly through the epidermis, or by inhalation. In "atopy patch testing", a concentrated HDM suspension is tested on the skin under occlusion. This method is frequently used as a model of the epidermal route. The clinical relevance of this method as a provocation test for AD is discussed. As opposed to atopy patch testing, we describe another method, namely, "allergen inhalation testing", as a model of the respiratory route. Twenty patients with AD underwent bronchial provocations with HDM extract in a double-blind, randomized, placebo-controlled study. In nine out of 20 AD patients, bronchial challenge with HDM evoked skin symptoms. All patients with HDM-induced dermatitis had a history of asthma, and as a group they had a higher mean total log-transformed IgE level than the "negative skin responders". Thus, the respiratory route may be relevant in the provocation of AD in a subset of AD patients and may represent an appropriate model of provocation in these patients. Furthermore, the role of HDM in urticaria and allergic rhinitis is discussed.

Allergens↗
PubMed1997

Severity scoring of atopic dermatitis: a comparison of three scoring systems.

In studies on atopic dermatitis (AD), different scoring systems are used to evaluate the severity of the disease. The objective of this study was to investigate agreement between observers in the assessment of the overall severity of AD, and interobserver variation in the assessment of severity of AD for each scoring item separately, using the Simple Scoring System (SSS), the Scoring Atopic Dermatitis (SCORAD) index, and the Basic Clinical Scoring System (BCSS), and, furthermore, to investigate agreement between these three scoring systems in the assessment of the overall severity of AD. Eighty-two patients (42 male) with AD, mean age 13.4 years (range 0.2-67.0), were included. Agreement between observers in assessing the overall AD severity scores, and interobserver variation in assessing AD severity of each scoring item separately were determined in 34 of these 82 patients by two physicians scoring the severity of AD by the three scoring systems. To determine agreement between the scoring systems, one physician scored the severity of AD in all patients with the three scoring systems. Agreement between observers and agreement between the three scoring systems was calculated by Cohen's kappa (kappa) and by the measure of agreement according to Bland & Altman. kappa > 0.4 represents fair agreement; kappa > 0.75 excellent agreement. In addition, interobserver variation for each scoring item separately was calculated by the Wilcoxon signed rank test. The mean differences (d) and the limits of agreement (d +/- 2 SD of the differences) between observers by the SSS and the SCORAD were -0.82 +/- 5.58 and -0.28 +/- 7.49, respectively, kappa between observers for the BCSS was 0.90 (95% CI 0.79-1.03). By the SSS, significant interobserver variation was found in assessing the severity of excoriations (P = 0.02) and scales (P = 0.02). By the SCORAD, significant interobserver variation was found in assessing the severity of edema/population (P = 0.04), erythema (P = 0.04), and excoriations (P = 0.01). No significant interobserver variation was found in assessing the extent of AD. The mean difference and the limits of agreement between the SSS and the SCORAD were -4.17 +/- 9.52. kappa between the SSS and the BCSS was 0.21 (95% CI 0.09-0.33), and kappa between the SCORAD and the BCSS was 0.38 (95% CI 0.26-0.51). We found good agreement between observers assessing the overall severity of AD in the lower and higher scoring rates by the SSS and the SCORAD, and excellent agreement by the BCSS. Significant interobserver variation was found on the isolated intensity items scales, excoriations, edema/population, and erythema. We found poor agreement between the three scoring systems in assessing the overall severity of AD, indicating that the SSS, the SCORAD, and the BCSS cannot be used interchangeably to assess the overall severity of AD.

Activities of Daily Living↗
PubMed1997

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.

Dermatitis, Contact↗
PubMed1997

Irritancy of antiseptics tested by repeated open exposures on the human skin, evaluated by non-invasive methods.

The aim of the study was to test the irritancy of 6 antiseptics in an open exposure model. The following agents were tested in their normal use concentrations using open exposures, 2x daily for 4 days in 20 subjects: chlorhexidine 4% (CH), chlorhexidine 0.5% in ethanol 70% (CE), ethanol 70% (ET), iodine 1% in ethanol 70% (IE), povidone-iodine 10% (PI) and sodium hypochlorite 0.25% (SH). Responses were evaluated by visual scoring, subjective irritancy scoring, stratum corneum hydration (Corneometer), transepidermal water loss and laser Doppler flowmetry. Exposure to SH had to be discontinued after 4 applications because of severe subjective irritation. The same held true for IE (7 applications), whereas the other agents were exposed 8x. All evaluation methods showed SH to be significantly more irritating than IE, which was in turn more irritating than CH, CE, ET and PI. Thus, it can be concluded that CH, CE, ET and PI were non-irritating in this open exposure model.

Adult↗
PubMed1996

Induction of atopic dermatitis by inhalation of house dust mite.

BACKGROUND: The pathogenetic role of house dust mite in atopic dermatitis remains controversial. Recent studies have shown that intensive epicutaneous contact of house dust mite allergen with premanipulated skin may induce dermatitis. It is, however, uncertain whether such conditions are met during natural contact with house dust mite. In the past, allergen inhalation has been suggested to induce exacerbation of atopic dermatitis. The aim of this study was to investigate whether dermatitis could be induced in patients with atopic dermatitis by inhalation of house dust mite. METHODS: Twenty patients with atopic dermatitis underwent bronchial provocations with house dust mite. Challenge tests were performed with four concentrations of a standardized house dust mite extract in a double-blind, randomized, placebo-controlled fashion. Spirometry was performed, and FEV1 was measured before and after each challenge dose. Changes in severity or localization of itching or erythema were recorded. RESULTS: In nine of 20 patients with atopic dermatitis bronchial challenge with house dust mite induced unequivocal skin symptoms after 1.5 to 17 hours. Pruritic erythematous lesions on noninvolved sites together with exacerbations of existing lesions were seen in three patients. Three patients had an exacerbation only, and three other patients had new lesions only. In eight of nine patients with house dust mite inhalation-induced dermatitis, skin symptoms were preceded by an early bronchial reaction. All patients with house dust mite-induced dermatitis had a history of asthma, and as a group they had a higher mean blood total IgE level compared with the "negative skin responders." One patient had pruritic erythema on the placebo challenge day, without a preceding bronchoconstrictive reaction. The number of patients who had a skin response on the house dust mite challenge day was significantly higher than the number of patients who had a skin response on the placebo day (p = 0.011 [Prescott's test]). CONCLUSIONS: The respiratory route may be relevant in the induction and exacerbation of dermatitis in a subset of patients with atopic dermatitis who have early bronchial reactions after house dust mite inhalation, a history of asthma, and an elevated blood total IgE level. Furthermore, these findings suggest a possible causal relationship between bronchial reactions and skin reactions.

Administration, Inhalation↗
PubMed1995

Irritant susceptibility and weal and flare reactions to bioactive agents in atopic dermatitis. I. Influence of disease severity.

The two main pathogenetic characteristics of atopic dermatitis (AD) are: (i) antigen-dependent 'specific' reactivity, and (ii) altered non-immunological 'non-specific' reactivity. Our understanding of the role of non-specific reactivity is hampered by the fact that methods available for its quantification are limited. The aim of the present study was to assess the usefulness of two parameters as quantitative measures of non-specific skin reactivity in AD: (i) susceptibility to repeated epicutaneous exposure to an irritant (sodium lauryl sulphate, SLS), assessed by visual scoring and transepidermal water loss (TEWL) measurement, and (ii) reactivity to intracutaneously injected bioactive agents (codeine, FMLP, histamine, methacholine, substance P, trypsin), assessed by measurement of weal and flare size. These two parameters were tested in a group of AD patients, subdivided according to the severity of their dermatitis, and a control group. The visual score and TEWL after SLS exposure tended to be higher in the AD group than in the control group. Furthermore, visual score and post-exposure TEWL were positively correlated with the dermatitis severity score. Weal size following injection of codeine, histamine and substance P, and flare size following injection of all agents, except methacholine, were significantly lower in the AD group than in the control group. Negative correlations were found between weal and flare sizes and the dermatitis severity score. These findings can be explained by down-regulation of structures involved in weal and flare reactions. In conclusion, we propose that epicutaneous irritant susceptibility and reactivity to intracutaneous bioactive agents may be useful indicators of non-specific skin reactivity in AD.

Adolescent↗
PubMed1995

Irritant susceptibility and weal and flare reactions to bioactive agents in atopic dermatitis. II. Influence of season.

Many atopic dermatitis (AD) patients have exacerbations of their skin disease in winter. These exacerbations may be caused by non-immunological 'non-specific' factors, such as low sun exposure and low temperature. To date, the influence of season on non-specific skin reactivity in AD has not been studied. The aim of the present investigation was to assess the influence of season on two skin parameters which may be used as quantitative measures of non-specific skin reactivity in AD: (i) susceptibility to repeated epicutaneous irritant (sodium lauryl sulphate, SLS) exposure, and (ii) weal and flare responses to intracutaneous injection of bioactive agents (codeine, FMLP, histamine, methacholine, substance P, trypsin). Four of 16 AD patients had dermatitis which was more severe in November than in July. Susceptibility to SLS was increased in November, both in AD patients and in control subjects. AD patients were more susceptible to SLS than control subjects in both July and November. Pre-exposure barrier function and skin hydration were reduced in November. The increased irritant susceptibility in November may be attributed to reduced barrier function, reduced skin hydration, and/or absence of the beneficial effects of ultraviolet light on cellular targets beneath the stratum corneum. Flare responses to codeine, methacholine, substance P and trypsin were also increased in November compared with July, especially in AD patients. However, smaller flares were observed in AD patients than in control subjects, in both July and November. Flare values were negatively correlated with dermatitis severity, probably because of down-regulation. Weal responses did not show a clear seasonal variation. Hence, susceptibility to epicutaneous irritants and reactivity to intracutaneously injected bioactive agents are parameters which may be used to monitor season-dependent changes in non-specific skin reactivity.

Adolescent↗
PubMed1990

Variability in transepidermal water loss of the skin: evaluation of a method to assess susceptibility to contact dermatitis in epidemiological studies.

Transepidermal water loss (TEWL) has been suggested to be a measure which can be used to identify subjects at risk for the development of contact dermatitis. Transepidermal water loss is high when the barrier function of the skin is impaired. It is assumed that subjects with a high TEWL have skin which is more permeable to substances causing contact dermatitis. The inter-individual and intra-individual variability of simultaneous TEWL measurements and TEWL measurements over a period of three weeks were estimated in healthy individuals. The intra-individual coefficient of variation (CV) of simultaneous measurements was 13.5%. The intra-individual coefficient of variation of the measurements on consecutive days was somewhat higher (15.1%). The intra-individual coefficients of variation were low compared to the inter-individual coefficients of variation. The results indicate that transepidermal water loss is a stable personal characteristic, which can be studied as a risk factor in epidemiologic studies on contact dermatitis.

Adult↗
PubMed1990

Susceptibility to irritants: role of barrier function, skin dryness and history of atopic dermatitis.

The susceptibility of the skin to various irritants was investigated with the aim of determining the role of the barrier function of the stratum corneum, skin dryness and whether a history of atopic dermatitis (AD) was a factor. The transepidermal water loss (TEWL) was measured using an evaporimeter and skin hydration using a Corneometer and by visual scoring. The group with a history of AD (n = 20) had a lower pre-exposure barrier function and a higher TEWL value following irritant exposure than the group with a history of allergic contact dermatitis (n = 18) and a control group (n = 18). Clinically dry skin was more susceptible than normal skin, though no difference was noted in the pre-exposure barrier function. The increased susceptibility to irritants in those with a past history of AD was probably due to impaired barrier function and/or the presence of a dry skin.

Adolescent↗
PubMed1990

Water vapour loss threshold and induction of cholinergic urticaria.

A patient is described with cholinergic urticaria (CU) in whom the symptoms could be provoked by gustatory stimuli. The aim of this study was to investigate whether there is a threshold of sweating (monitored by skin water vapour loss (SVL) measurements) at which CU can be provoked. Provocations with lemon and sal-ammoniac liquorice induced transient sweating differing both in degree and duration. Only 'doubly salted' liquorice, which caused the most intense sweat response, resulted in urticarial lesions. This findings suggest a threshold dependency for the induction of CU. SVL measurement may be a useful method for the evaluation of sweating tests in CU patients.

Body Water↗
PubMed1990

The transient and cumulative effect of sodium lauryl sulphate on the epidermal barrier assessed by transepidermal water loss: inter-individual variation.

The aims of the investigation were: 1) to study the inter-individual variation in time course of TransEpidermal Water Loss and of clinical manifestations after a 24-h single exposure to Sodium Lauryl Sulphate. This TEWL time course (expressed as the difference in TEWL between the day of patch removal and a subsequent day) reflected the epidermal barrier response to the damage caused by SLS; 2) to investigate the association between the TEWL time course after the single SLS exposure and the TEWL value after 4-day repeated SLS exposure (as a model for cumulative irritation). The 35 healthy subjects tested could be divided into four sub-groups according to the day of their maximum TEWL value after the single SLS exposure (days 2 to 5). For the whole group, inter-individual variation in TEWL course was most pronounced in the first days following the single SLS application. Moreover, there was an inverse relationship (R = -0.61) between TEWL course during the first days after the single exposure and the TEWL value after 4-day repeated exposures. It is concluded that this association illustrates the importance of an adequately responding barrier function against the continuous exposure to irritants in daily life.

Adult↗