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Biomedical subjects

J P Nater

Publications and source records attributed to J P Nater.

At least 19 recordsLinked to original sources

Evaluation of a self-administered questionnaire on hand dermatitis.

The purpose of the study was to evaluate a self-administered questionnaire on hand dermatitis that was developed to identify persons with hand dermatitis in epidemiological studies. A total of 109 nurses were subject to dermatological examination of the hands within 1 month of returning the questionnaire. 2 types of questionnaire diagnoses were made: a 'symptom-based' diagnosis and a 'self-reported diagnosis'. These were compared to the medical diagnosis of hand dermatitis. The prevalence of hand dermatitis in the 12 months before the study, based on the medical diagnosis, was 18.3%. The prevalence according to the symptom-based diagnosis and the self-reported diagnosis was 47.7% and 17.4%, respectively. The sensitivity and specificity of the symptom-based diagnosis were 100% and 64%, respectively. It is concluded that the symptom-based diagnosis can be used as screening instrument for the detection of cases in large study populations, if followed by dermatological examination of persons with a positive diagnosis. The sensitivity and specificity of the self-reported diagnosis were 65% and 93%, respectively. It is concluded that the self-reported diagnosis can be used to obtain a rough estimate of the prevalence, although comparison of prevalence figures between study populations may be distorted due to a difference in reporting of hand dermatitis. The results of the study illustrate the size of the differences in prevalence estimates that may arise as a result of differences in the definition and method of diagnosing hand dermatitis.

Adolescent↗

Oscar Wilde's skin disease: allergic contact dermatitis?

During the last years of his life, Oscar Wilde (1856-1900) suffered from a suppurating otitis media as well as from an unidentified skin disease. The eruption was localized to his face, arms, chest and back and itched severely. A new theory is suggested, based on the fact that Wilde almost certainly used a dye to conceal his rapidly graying hair. He sensitized himself to p-phenylenediamine and developed a stubborn allergic contact dermatitis. Patch testing, the only proof of such a diagnosis, had not yet been devised.

Dermatitis, Allergic Contact↗

Patch tests with house dust mite antigens in atopic dermatitis patients: methodological problems.

Patch tests with house dust mite allergens were performed in 21 atopic dermatitis patients with a positive prick test and RAST for house dust mite. Variables in methodology of patch testing, i.e. allergen concentration, application time, and intensity of tape stripping, were studied. Tests were performed with Dermatophagoides pteronyssinus solutions containing 20X, 100X and 500X the prick test concentration and purified HDM antigen: 10 and 50 micrograms/ml P1Ag solution. The series was applied on 8X or 15X tape-stripped and clinically normal skin on the back during 24 and 48 h. Non-specific reactions due to tape stripping, fixation tape or patch test occlusion were frequently observed: after 15X tape-stripping in 3/7 (24-h application) and 6/7 (48-h application) patients, after 8X tape-stripping in 2/19 (24-h application) and 8/19 (48-h application) patients. Reactions clinically assessed as specific occurred in 6/21 (29%) atopic dermatitis patients, 4/6 occurring in the 10 patients with a serum IgE greater than 1000 kU/l. High allergen concentrations and 48 h of application increased the number of patients with specific reactions. If 15X tape-stripping had been omitted, 2/3 patients tested in this manner and showing specific test reactions would have been negative. Further conclusions regarding the value and the preferable method of patch testing with atopic allergens require an in vitro control test.

Adolescent↗

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↗

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↗

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↗

The influence of repeated exposure to surfactants on the human skin as determined by transepidermal water loss and visual scoring.

The purpose of this study was to develop a new model for the induction of chronic irritant contact dermatitis, which would reflect well the conditions of daily practice. Various weak irritant agents were tested for irritating potency on the skin and the sensitivity of transepidermal water loss (TEWL) measurements in the detection of early skin changes was also studied. 10 widely used surfactants and 1 solubilizer were applied to the skin of the forearms of healthy volunteers in aqueous solutions of 12.5 millimoles/l for 45 min twice daily for 3 weeks. The effect on the skin was evaluated daily by means of TEWL measurements and by a visual scoring system. Each solution caused an increase in TEWL value over time due to the cumulative irritating action on the epidermal barrier. This increase in TEWL was different for the various solutions, resulting in different mean TEWL values on the last day of the experiment. Thus, it was possible to rank the agents according to irritating potency. This ranking order was the same in almost every individual and remained constant during the 3 weeks. In comparison with the visual scoring system, the TEWL measurements were more sensitive in the detection of early changes in the skin.

Adult↗

Comparability and reproducibility of the results of water loss measurements: a study of 4 evaporimeters.

A study was made of the comparability and reproducibility of the results of measurements of water loss, both in vitro and in vivo, using 4 ServoMed Evaporimeters (3 single-probe and 1 double-probe instrument). The optimum time for recording transepidermal water loss (TEWL) after the initial application of the probe to the skin (in vivo), and the best technique for optimizing the accuracy of measuring TEWL were determined. An evaporation device with a constant level of water loss was constructed for in vitro studies. The volar aspect of the right forearm skin of one subject was used in vivo. Both in vitro and in vivo measurements showed that there were some differences between the results of 4 of the 5 probes. The other probe was distinctly out of range. For all probes, the reproducibility of results of successive measurements was high. Stabilization of TEWL values was reached for all probes from 30-45 s after their initial application to the skin. It is recommended that TEWL be recorded for a further 30-s period, after the initial stabilization (45 s), and that this be taken as the true value. The manufacturer's recommended calibration procedure is based only on adjustments for the standard specified humidities and zero water loss. The importance of incorporating an additional calibration procedure which includes adjustments for an actual standard constant water loss is thus strongly stressed.

Calibration↗

Baseline transepidermal water loss (TEWL) as a prediction of susceptibility to sodium lauryl sulphate.

The rôle of different factors in the susceptibility of the skin to weak irritants was studied by means of multiple linear regression models. The skin of 37 healthy subjects was exposed to a solution of sodium lauryl sulphate of low molarity 2 x daily for 4 days. The condition of the skin was evaluated by transepidermal water loss (TEWL) measurements on the 1st day (before exposure, TEWL1) and on the 5th day of exposure (TEWL5), and by a visual scoring system. The TEWL5 value was strongly related to the TEWL1 value (R = 0.71). The influence of such factors as history of mucosal atopy, history of sensitivity to soap, dry skin, skin type, sex and age on the TEWL5 value was negligible. The baseline TEWL level (TEWL1) might be a reliable indication of an individual's susceptibility to weak irritants.

Adult↗

Prediction of susceptibility to an irritant response by transepidermal water loss.

The roles of the natural permeability of the stratum corneum to water, and the changes in that permeability effected by a single patch test, were investigated as parameters to predict the susceptibility of the skin to repeated exposures of an irritant. One site on the forearm skin of 27 non-atopic healthy subjects was exposed to a 0.5% concentration of sodium lauryl sulphate by a single occlusive 24-h patch. Another site was exposed to a twice daily 4-day repeated occlusive patch with the same irritant solution. The effects were evaluated by transepidermal water loss measurements made prior to the applications (baseline) on day 1 (BASE), following the single 24-h patch on day 2 (SINGL), and following the 4-day repeated applications on day 5 (REPET). Individuals with higher BASE had higher SINGL (R = 0.80, P less than 0.001) and higher REPET (R = 0.76, P less than 0.001). There was also a significant linear correlation between SINGL and REPET (R = 0.63, P less than 0.001). Multiple linear regression analysis of results, however, indicated that a high baseline TEWL is better indication of an individual's increased susceptibility (high REPET) to weak irritants than a high TEWL value following a single 24-h patch test. Baseline TEWL may therefore be used as a reasonably accurate preliminary "predictive" screening test for susceptibility to irritants.

Adult↗

The intra- and inter-individual variability and reliability of transepidermal water loss measurements.

An analysis of variance was conducted to estimate the intra- and inter-individual variations in TEWL on the forearms, by sites (8 measurement sites) and by days (10 different days), in 30 non-exposed healthy individuals. The estimated intra- and inter-individual variations, by sites, were 15.5% and 84.5%, respectively, the sum of the 2 components always being 100%. With the exclusion of the 2 most distal sites near the wrist, which had significantly higher baseline TEWL values and fluctuations in TEWL, an improvement in the intra-individual variation was obtained. Thus, of the 6 sites, the estimated intra- and inter-individual variations were 8.4% and 91.6%, respectively. This finding supports the exclusion of these most distal sites for future investigations. The estimated intra- and inter-individual variations, by days, were 20.6% and 79.4%, respectively. The low site-to-site (8.4%) and day-to-day (20.6%) intra-individual variations, as compared to the large inter-individual variations of the same (91.6% and 79.4%), indicate that baseline TEWL is a stable personal characteristic. Thus, individual susceptible to irritant contact dermatitis (ICD), due to occupational exposure, may be reliably characterized by utilizing their baseline TEWL values, for "prediction" of risk in epidemiological field studies.

Adult↗

Transepidermal water loss with and without sweat gland inactivation.

The influence of eccrine sweating on transepidermal water loss (TEWL) was investigated. TEWL was simultaneously measured on both forearms, with and without topical inactivation of the eccrine sweat glands by 0.3 ml of 0.5% aqueous scopolamine hydrobromide (HBr), applied under 1 h occlusive patches. The degree of sweat inhibition, after exercise, was measured at 2, 3 and 4 h after patch removal. In 42 out of 44 subjects, complete sweat inhibition (on exercise) was achieved only at 4 h after removal. After a 15-min rest in a room at 20 degrees C, the pre-exercise TEWL values (at 4 h) on the treated and untreated sites were not different (P greater than 0.05), in 38 out of 44 subjects. By this rest period, sweating due to slight physical, thermal or even emotional stimuli may be prevented in most subjects. In the other 6 subjects, the pre-exercise TEWL values (at 4 h) on the untreated site were 1-1.8 g/m2h higher than (P less than 0.001) on the treated site, due to emotional sweating. Thus, accurate baseline TEWL measurements may only be made after anticholinergic suppression of the sweat glands. In this way, accurate TEWL measurements may be made even outside favourable laboratory conditions, at industrial sites etc., where circumstances are far from ideal. The effect of this agent applied to a skin site previously irritated artificially by a 24-h occlusive sodium lauryl sulphate (SLS, 0.3 ml, 0.5% aq.) patch, was also investigated in 17 subjects. In all subjects, 4 h after removal, sweating (on exercise) was completely inhibited on the scopolamine-treated site, pre-irritated with SLS.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Maculopapular rash due to coumarin derivatives.

The case history is presented of a patient who developed a maculopapular rash following treatment with 3 different coumarin derivatives. Apparently cross-sensitivity between coumarin derivatives may occur.

Acenocoumarol↗