Biomedical subjects

Jochen Brasch

Publications and source records attributed to Jochen Brasch.

22 records · Page 2Linked to original sources

PubMed2002

Patch tests with thiurams at 0.25% pet. and 1% pet. are of equal diagnostic value.

Thiuram mix is tested in the standard series at a test concentration of 1% pet. The single thiurams (DPTD, TMTD, TMTM, TETD), however, are usually tested at 0.25% pet. in Germany. In other countries, the individual components of thiuram mix are tested at 1% pet. The German Contact Dermatitis Research Group (DKG) compared both patch test concentrations in 530 patients in order to find out if (i) a significant number of positive patch tests are missed by testing at the lower concentration, (ii) problems with irritant test reactions occur by increasing the test concentration to 1%, and (iii) the sensitivity of the thiuram mix rises when the breakdown test is done with the higher concentration. Slightly more positive reactions were seen with the higher concentration, but this increase did not reach statistical significance. The reaction index, as a measure for the relation of positive to irritant and/or questionable reactions, remained unchanged for the individual thiurams. The sensitivity of the mix also did not change when the breakdown test was performed with 1% pet. instead of 0.25% pet. Thus, we conclude that both concentrations are of equal diagnostic value in patch testing.

Dermatitis, Allergic Contact↗

PubMed2002

Lyral has been included in the patch test standard series in Germany.

Lyral 5% pet. was tested in 3245 consecutive patch test patients in 20 departments of dermatology in order (i) to check the diagnostic quality of this patch test preparation, (ii) to examine concomitant reactions to Lyral and fragrance mix (FM), and (iii) to assess the frequency of contact allergy to Lyral in an unselected patch test population of German dermatological clinics. 62 patients reacted to Lyral, i.e. 1.9%. One third of the positive reactions were + + and + + +. The reaction index was 0.27. Thus, the test preparation can be regarded a good diagnostic tool. Lyral and fragrance mix (FM) were tested in parallel in 3185 patients. Of these, 300 (9.4%) reacted to FM, and 59 (1.9%) to Lyral. In 40 patients, positive reactions to both occurred, which is 13.3% of those reacting to FM, and 67.8% of those reacting to Lyral. So the concordance of positive test reactions to Lyral and FM was only slight. Based on these results, the German Contact Dermatitis Research Group (DKG) decided to add Lyral 5% pet. to the standard series.

Aldehydes↗

PubMed2002

Diagnostic screening for contact allergy to mercaptobenzothiazole derivatives.

BACKGROUND: A patch test with an allergen mix used as screening test should be highly sensitive so that allergic patients are not missed. A previous analysis based on patch test data from 1990 to 1993 has shown that the mercapto mix lacked sensitivity. Chemical analyses on the stability of the mix components led to a new composition of the mix in 1995. METHODS: The authors analyzed retrospectively patch test data from the Information Network of Departments of Dermatology to evaluate the sensitivity of the newly formulated mercapto mix and mercaptobenzothiazole (MBT) for detecting contact allergies to the 3 MBT derivatives contained in the present mix. RESULTS: The new mercapto mix had a sensitivity of only 0.60, whereas MBT had a significantly higher sensitivity of 0.69. However, even this means that more than 30% of the patients allergic to MBT derivatives are missed. The combination of MBT and mercapto mix had a sensitivity of 0.77 for detecting contact allergies to the MBT derivatives. CONCLUSION: The German Contact Dermatitis Research Group decided to test both mercapto mix and MBT within the standard series, and to apply the 3 single components of the mix in case of a positive reaction to the mix or MBT.

Allergens↗

PubMedDate not supplied

The MOAHLFA index of irritant sodium lauryl sulfate reactions: first results of a multicentre study on routine sodium lauryl sulfate patch testing.

In a multicentre study of the German Contact Dermatitis Research Group, sodium lauryl sulfate (SLS) 0.25% and 0.5% aq. has been added to routine allergen patch tests to assess its properties as a convenient diagnostic indicator of individual susceptibility to irritation at the time of patch testing. Previous studies indicated that irritant SLS reactivity may be related to individual factors such as age and sex. As these factors are, in turn, among the important predictors of contact allergy to many allergens, e.g. summarized in the 'MOAHLFA index', the impact of the MOAHLFA factors on irritant SLS patch test reactivity, and thus a potential for confounding, was assessed in the 5971 participating patients. As a result of 2 logistic regression analyses with an irritant reaction to 0.25% and 0.5% SLS, respectively, as outcome, male sex was identified as a relatively weak but significant risk factor (OR 1.38), while age 40 years or older was an even weaker risk factor (OR 1.22 and 1.15, respectively). Upon detailed analysis, no clear age gradient could, however, be identified. 1-day exposure time almost halved the odds of an irritant SLS reaction. In conclusion, this type of SLS patch test can be regarded as robust, indicating individual irritability relatively independent from the individual factors analysed here.

Adult↗