1,721,028 research outputs found
The profile of patch test reactions to common contact allergens is related to sex
No full textBackground: Women are more often patch tested than men, and the reactivity to patch test allergens is dependent on sex. However, it is unclear whether the profiles of test reactions are also sex-related. Objective: To compare the profiles of patch test reactions of men and women. Methods: Sex-related reaction profiles of 16 common patch test allergens were analysed based on data of 47 626 patients filed by the Information Network of Departments of Dermatology in Germany. The proportions of weak positive reactions and of questionable and irritant reactions were evaluated by calculating the positivity ratio (PR) and the reaction index (RI) separately for men and women for each allergen. Results: Of the 16 allergens evaluated, 8 had a higher PR and a higher RI in women than in men. 4 allergens had a lower PR and another 4 had a lower RI in women than in men. For allergens with similar sensitization prevalence in men and women, female sex was associated with a higher PR and RI (P < 0.01). Conclusions: There is a marginal disparity in the reactivity of men and women to patch test allergens that is probably not of clinical relevance but constitutes a scientific challenge
Reproducibility of patch testing - an analysis of concordance with synchronous application
No full textThe reproducibility of diagnostic patch testing is an important quality criterion which has been addressed by several studies. The reanalysis presented utilises data of a previous study of the German Contact Dermatitis Research Group (DKG) on the synchronous left versus right reproducibilty of patch testing with 10 allergens of the standard series, quantifying reproducibility with Cohen's kappa coefficient. The degree of concordance between dichotomised reactions at 72 hours ("positive" versus "not positive") varies between allergens. The kappa coefficient was 0.80 and above for nickel sulphate, p-phenylenediamine, cobalt chloride and balsam of Peru, while for the two allergens tested in water, i.e., (chloro-) methylisothiazolinone and formaldehyde, it was below 0.70. Longer patch test exposure (48 hours compared to 24 hours) mostly improved concordance, which was, however, a significant effect only for potassium dichromate (p < 0,05). For the evaluation of concordance between chemically related allergens in terms of cross-reactivity, a quotient between the κ coefficient found with the related allergens and the κ coefficient found with the marker allergen involved (with synchronous duplicate application) is suggested
Reproducibility of patch testing - an analysis of concordance with synchronous application
No full textThe reproducibility of diagnostic patch testing is an important quality criterion which has been addressed by several studies. The reanalysis presented utilises data of a previous study of the German Contact Dermatitis Research Group (DKG) on the synchronous left versus right reproducibilty of patch testing with 10 allergens of the standard series, quantifying reproducibility with Cohen's kappa coefficient. The degree of concordance between dichotomised reactions at 72 hours ("positive" versus "not positive") varies between allergens. The kappa coefficient was 0.80 and above for nickel sulphate, p-phenylenediamine, cobalt chloride and balsam of Peru, while for the two allergens tested in water, i.e., (chloro-) methylisothiazolinone and formaldehyde, it was below 0.70. Longer patch test exposure (48 hours compared to 24 hours) mostly improved concordance, which was, however, a significant effect only for potassium dichromate (p < 0,05). For the evaluation of concordance between chemically related allergens in terms of cross-reactivity, a quotient between the κ coefficient found with the related allergens and the κ coefficient found with the marker allergen involved (with synchronous duplicate application) is suggested
The profile of patch test reactions to common contact allergens is related to sex
No full textBackground: Women are more often patch tested than men, and the reactivity to patch test allergens is dependent on sex. However, it is unclear whether the profiles of test reactions are also sex-related. Objective: To compare the profiles of patch test reactions of men and women. Methods: Sex-related reaction profiles of 16 common patch test allergens were analysed based on data of 47 626 patients filed by the Information Network of Departments of Dermatology in Germany. The proportions of weak positive reactions and of questionable and irritant reactions were evaluated by calculating the positivity ratio (PR) and the reaction index (RI) separately for men and women for each allergen. Results: Of the 16 allergens evaluated, 8 had a higher PR and a higher RI in women than in men. 4 allergens had a lower PR and another 4 had a lower RI in women than in men. For allergens with similar sensitization prevalence in men and women, female sex was associated with a higher PR and RI (P < 0.01). Conclusions: There is a marginal disparity in the reactivity of men and women to patch test allergens that is probably not of clinical relevance but constitutes a scientific challenge
Strong allergic patch test reactions may indicate a general disposition for contact allergy
No full textBackground: Patch test patients have two or more positive reactions to unrelated allergens more often than to be expected by chance. This study evaluates synchronous patch test reactions to test the hypothesis that in such cases an allergen-independent disposition for contact sensitization may be involved. Methods: Data of 87 834 patients tested with a standard patch test series in 42 centers of a Central European Network were retrospectively evaluated. Analyses were done for synchronous positive reactions of graded strength to nickel sulfate, fragrance mix, and to those five allergens that followed in frequency of positive results. All seven allergens selected were not related by chemical structure or exposure. Descriptive univariate and bivariate analyses as well as a polytomous logistic regression analysis were performed. Odds ratios with 95% confidence intervals were calculated. Results: With an increasing strength of a positive reaction to nickel or to fragrance mix the likelihood of further positive reactions to unrelated contact allergens increased significantly, and the mean strength of such additional reactions raised steadily with an increasing strength of a nickel or fragrance reaction. Conclusions: Our findings support the idea that patients who respond with a strong patch test reaction may have a particular general disposition to acquire contact sensitivity to additional unrelated allergens. They should therefore not only be advised to avoid their known allergen but in addition to minimize exposure other contact allergens
Simultaneous sodium lauryl sulphate testing improves the diagnostic validity of allergic patch tests. Results from a prospective multicentre study of the German Contact Dermatitis Research Group (Deutsche Kontaktallergie-Gruppe, DKG)
No full textBackground There is evidence that a higher skin susceptibility may induce nonspecific erythematous or weak positive reactions to contact allergens in patch testing. Objectives To evaluate whether simultaneous application of sodium lauryl sulphate (SLS) along with diagnostic patch tests with contact allergens can provide information regarding skin irritability which may help to discriminate allergic from nonspecific irritant reactions to contact allergens. Methods Between July 2001 and June 2003, this prospective study collected patch test data of 5971 patients from 19 centres in Germany and Austria in the Information Network of Departments of Dermatology (IVDK). In addition to contact allergens (standard series and eight known 'problematic' allergens with a low reaction index and a high positivity ratio: 1,3-diphenylguanidine, amerchol L-101, benzalkonium chloride, benzoyl peroxide, cocamidopropyl betaine, octyl gallate, phenyl mercuric acetate and propylene glycol), patches with SLS 0.5% and 0.25% aq. were applied. Reactions to the allergens and to SLS were analysed at the IVDK data centre. The association between an erythematous or positive reaction to a certain allergen and an irritant reaction to SLS was assessed with logistic regression analysis, at the same time controlling for the influence of age and sex. Results Of the 29 allergens of the standard series, 23 and 21 gave a higher percentage of nonspecific erythematous reactions in patients with an irritant reaction to 0.25% and 0.5% SLS, respectively, in comparison with SLS-negative patients. All eight 'problematic' allergens gave an increased percentage of nonspecific erythematous reactions. Similarly, 22 and 21 allergens of the standard series gave a higher percentage of positive allergic reactions in patients with an irritant reaction to 0.25% and 0.5% SLS, respectively, and seven of the eight 'problematic' allergens gave a higher percentage of positive allergic rections (exception: octyl gallate). For most allergens, the markers of skin reaction (reaction index and positivity ratio) were worse in SLS-positive patients. Differences were more pronounced when testing with SLS 0.25% than with SLS 0.5%. Conclusions Because there is a convincing association between skin irritability (evaluated by SLS test) and the degree of skin reaction to contact allergens, the SLS test may help in deciding whether a doubtful erythematous or weakly 'positive' skin reaction should be interpreted as allergic or irritant
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