1,721,127 research outputs found
Iodopropynylbutyl carbamate 0 center dot 2% is suggested for patch testing of patients with eczema possibly related to preservatives
No full textBackground Iodopropynyl butylcarbamate (IPBC) is a new preservative in medical and cosmetic leave-on products. Although cases of allergic contact dermatitis to IPBC have been reported, it is not known whether the usual test concentration of 0.1% is appropriate for screening tests with IPBC. Objectives To determine the concentration of IPBC that should be used in screening patch tests. Methods An analysis was made of data filed by 26 centres of dermatology on patch tests performed with one or two concentrations of IPBC (0.1%, 0.2%, 0.3% or 0.5%) in 8106 unselected patients. Criteria used to determine the best test concentration of IPBC were the reaction index, the positivity ratio, the rate of crescendo reactions, and the relations between IPBC reactions and the MOAHLFA index irritant reactions to sodium lauryl sulphate (SLS), and allergic reactions to other contact allergens including preservatives. Results IPBC 0.1%, 0.2%, 0.3% and 0.5% yielded 0.5%, 0.8%, 1.3% and 1.7% positive reactions, but this increase was accompanied by an even greater increase in doubtful and irritant reactions. These figures and the other criteria examined suggested the range of suitable test concentrations of IPBC to lie between 0.2% and 0.3%. A detailed analysis of MOAHLFA indices and of associations between reactions to IPBC and reactions to other allergens and to SLS showed that most of the positive reactions to IPBC 0.2% can be assumed to be allergic ones and that with IPBC 0.2% fewer false-positive reactions can be expected than with IPBC 0.3%. Conclusions Patch testing with IPBC 0.2% is suggested for patients with eczema possibly related to preservatives
Patch testing of nickel sulfate and potassium dichromate with a standardized ready-to-use test system gives highly reproducible results: A double-blind multicentre study
No full textThere is still some doubt about the reproducibility of patch tests, A sound assessment needs optimized and unbiased studies. This study analysed the results of a double-blind multicentre study with nickel sulfate and potassium dichromate patch tests attached synchronously to both sides of the back of patients with a history of nickel allergy, conducted with a highly standardized randomized test system (TRUE-test((R))), Out of 589 patients tested, a total of 388 had responded with allergic reactions to nickel sulfate and 130 to potassium dichromate, The reproducibility of positive nickel (dichromate) patch tests mas 99.2% (90.8%), The reaction index nas also calculated, which relates the number of allergic reactions obtained with a test preparation to the number of questionable and irritant reactions; the reaction index can range from -1 (questionable and irritant reactions only occur) to 1 (allergic reactions only occur). For nickel sulfate the reaction index mas 0.91, but it was only 0.23 for potassium dichromate, as a result of considerably more questionable reactions. In conclusion, a highly synchronous reproducibility of results can be achieved by using a well-standardized patch-test system, especially with nickel sulfate, However, distinct allergens and test systems need to be evaluated separately
Guidelines of the German Dermatological Society (DDG) for conducting epidermal tests with contact allergens
No full textAllergic Reactions to Pigments, Metals, and More? Body Art from the Allergist’s Point of View
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Positive nickel patch tests do not intensify positive reactions to adjacent patch tests with dichromate - Results from a double-blind multicentre study of the German Contact Dermatitis Research Group (Deutsche Kontaktallergie-Gruppe, DKG)
No full textThe possible interference of neighbouring allergic patch-test reactions is still an open question. In this study, we investigated whether there is a distance-related mutual modification of neighbouring allergic patch-test reactions to nickel sulfate and potassium dichromate. We used a double-blind multicentre study design with randomized attachment of special TRUE Tests with 1, 3 and 7 cm distance between nickel sulfate and potassium dichromate patches. 589 patients with a history of nickel allergy (523 female, 66 male) were tested, with a mean age of 35 years. A log-linear modelling approach was used for statistical assessment of the relation between the distance separating neighbouring patch tests with nickel and dichromate and the reactions to the allergens. Non-reproducibility coefficients were compared by the generalized version of Fisher's exact test for arbitrary 2-dimensional contingency tables. For the left side of the back, virtually no differences (p=0.70) were found in the reaction patterns obtained for the 3 distances separating nickel and dichromate patch tests. On the right side of the back, the number of reactions to dichromate patches with only 1 cm distance from moderate/strong nickel reactions was lower than the number of positive dichromate tests at larger distances from nickel tests (on the border of statistical significance: p= 0.05). Corresponding side-related results were obtained for subgroups of patients with and without a history of atopic dermatitis. The non-reproducibility of reactions to dichromate was not significantly related to the distance between neighbouring tests. Our data argue against a "spillover" effect of strong/moderate nickel reactions, but indicate that such reactions may, under certain conditions, attenuate adjacent reactions to an unrelated allergen. In the case of future verification, this will have implications for the interpretation of patch tests
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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