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Notes: To determine normal levels of transepidermal water loss (TEWL), capacitance and sebum according to different sex and age groups, 93 healthy subjects were studied at 14 different anatomical locations with three different instruments: the Evaporimeter EP 1, the Corneometer CM 820, and the Sebumeter SM 810, evaluating respectively the transepidermal water loss, the capacitance and the causal level of sebum. Differences depending on the anatomical site were noticed. Unlike the capacitance, the transepidermal water loss and the causal level of sebum significantly decreased according to age. Furthermore, in some sites, male subjects showed a significantly higher transepidermal water loss than females, while hydration of the horny layer expressed by the capacitance showed an opposite trend. Correlations between the above-mentioned skin parameters were calculated: a positive correlation between TEWL and hydration was observed only at plantar and palmar areas.

Notes: 5 non-disperse azo dyes, used for colouring natural fibers, were added to the standard patch test series, as 5% pet. Preparations, 1814 consecutive patients attending the patch test clinic were patch tested, of whom 16 (0.88%) reacted to the newly added dyes: 8 to Direct Orange 34. 5 to Acid Yellow 61. 2 to Acid Red 359 and 1 to Acid Red 118. On the basis of clinical history and results of patch tests with pieces of rubrics, contact sensitization to non-disperse azo dyes seemed to be related to the appearance of skin lesions at least in 8 subjects. We conclude that systematic exploration of the sensitizing potential of textile dyes, selected after careful investigation, can provide additional information on the frequency of occurrence of textile dye dermatitis, supporting individual investigation in sensitized subjects.

Notes: Abstract The human skin blanching assay is a well established method for ranking the efficacy of corticosteroids after epicutaneous application. Vasoconstriction is a pharmacological activity, which correlates well with the clinical efficacy, the intensity of skin blanching after a single application under occlusion corresponding, generally, to the clinical efficacy after repealed application without occlusion. However, in studies dealing with the comparison between the vasoconstriction assay and the evaluation of the clinical effects on inflammatory skin diseases, some exceptions to this correlation have been reported. Therefore, in a pre-clinical phase, it would be useful to combine the blanching assay with at least one anti-inflammatory assay. In the present study the blanching assay and the allergic contact dermatitis inhibition test were performed in parallel, in order to compare the two testing procedures in the same group of subjects, utilizing standardized study designs supported by objective means of evaluation. Three commercial preparations of corticosteroids containing clobetasol propionate (CP), clobetasone butyrate (CB) and hydrocortisone acetate (HA), respectively, were employed both to treat nickel-induced positive patch test responses on the volar forearms, and to perform a vasoconstrictor assay on normal forearm skin in 16 nickel-sensitised healthy volunteers. For evaluating skin blanching, we employed colorimetric measurements, whereas for the quantitative determination of the inhibition of the intensity of allergic patch test reactions, 20 MHz B-scanning supported by image analysis was used. Both colorimetric and echogenicity values enabled us to distinguish between the three corticosteroids (at the 17 h evaluation and the 64 h assessment, respectively). A fair correlation was noted between colorimetric and echogenicity values. Both testing procedures ranked the three corticosteroids in the expected order. Corticosteroid preparations should be compared using methods which allow different effects to be simultaneously monitored, without involving a high number of patients. We are proposing this double procedure for the parallel intraindividual evaluation of the vasoconstrictory action and the anti-allergic activity of topical steroids.

Notes: Background/aims: The possibility of identifying allergic reactions while they are not clinically evident could prove extremely useful in studying the evolution of skin responses in experimentally-induced contact dermatitis. In drug research and in cosmetological research, the sensitizing properties of new molecules or haptens present in the product in a low concentration also need be clarified. The object of the present study was to validate noninvasive techniques and their use for the study of subclinical allergic reactions. Methods: 70 nickel-sensitized subjects previously standard tested with 5% nickel sulphate in petrolatum were challenged with a 0.05% nickel sulfate solution on the volar aspect of the forearm, application for 24 h and measurement at 72 h. Colorimetry, evaporimetry (transepidermal water loss, TEWL) and high-frequency echography were used to characterize reactions. Results: Colorimetry and TEWL did not show any significant differences between patch test areas and control areas. Skin thickness determination, conversely, evidenced a significant increase both with respect to baseline values and control areas. Conclusion: Echographic evaluation is able to detect modification of skin thickness of subclinical allergic patch test reactions to nickel sulfate while colorimetry and TEWL failed to detected such minute changes.

Notes: Background/aims: Skin thickness relative to age is complex and may be influenced both by intrinsic changes, extrinsic changes related to sun exposure and constitution, including sex. Age-related changes may also differ in different anatomical sites. The object was to characterize skin aging relative to these influences.Methods: A-mode and B-mode high-frequency (20 MHz) ultrasound examination was performed using the Dermascan C. 162 subjects were examined (91 women, 71 men) in the age range 27 to 90 years. 6 anatomical locations (forehead, cheek, volar forearm, dorsal forearm, upper abdomen, buttocks) were studied.Results: Females have thinner skin than men. Subjects aged more than 70 years have significant thinning of the skin. Age-related thinning is more pronounced in women. Relative skin-thickness decrease is less at sun-exposed areas in comparison with protected areas.Conclusion: Ultrasund examination allows characterization of skin aging, and the influences of sex and anatomical site with sun-induced changes were differently superimposed on intrinsic changes and constitution.

Notes: Background/aims: Sodium lauryi sulfate (SLS) is the most frequently used model for studying in vivo irritation. It is also one of the most frequent surfactants in soap preparations and cosmetic emulsions. To investigate the irritant potential of sodium salts of n-alkyl sulfates with different carbon chain length (n=8, 12, 14), we applied these substances on the volar forearm of 10 healthy human volunteers aged 24 to 35 years.Methods: To allow the equal solubilization of the surfactants, we used a 0.2% solution (w/v). A colorimeter to assess erythema, an evaporimeter to assess transepidermal water loss (TEWL) and a corneometer to evaluate skin hydration were employed to estimate the effects of the chemicals on the skin. Evaluations were performed at baseline, 24, 48 and 72 h.Results: TEWL had increased at 24 h: SLS showed the highest increase, followed by octyl and tetradecyl sulfate. Skin hydration was reduced for the three substances, and a slight increase in redness was noticed. TEWL and hydration values at different times of assessment enabled the ranking of n-alkyl sulfates in the following order: lauryi sulfate, tetradecyl sulfate and octyl sulfate.Conclusions: We could not prove a direct correlation between barrier impairment, skin dehydration and surfactant-induced inflammation, as evaluated by color measurements. This discrepancy suggests that the irritation potential of n-alkyl sulfates at the dermal level differs from their action on skin barrier.