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Johannes Geier

Publications and source records attributed to Johannes Geier.

32 records · Page 2Linked to original sources
PubMed2003

Occupational rubber glove allergy: results of the Information Network of Departments of Dermatology (IVDK), 1995-2001.

About 21% of the patients with occupational contact dermatitis registered in the Information Network of Departments of Dermatology (IVDK) in the years 1995-2001 were patch tested due to suspected rubber glove allergy. We analysed reaction frequencies to thiurams, dithiocarbamates, mercaptobenzothiazole (MBT) and its derivatives, thioureas, and 1,3-diphenylguanidine (1,3-DPG). Thiurams were by far the most frequent rubber allergens in these patients (16.2% positive reactions, age- and sex-standardized), and the reaction frequency showed a decline from 20.9% in 1997 to 12.8% in 2000. However, this trend was not statistically significant, and was followed by an increase to 16.5% in 2001. All other rubber allergens showed no time trend at all. Although, according to manufacturers' information, the use of dithiocarbamates and MBT derivatives in rubber glove production increased in recent years, these allergens elicited positive reactions in only about 3% of the patients tested, and showed no increasing trend. Thioureas and 1,3-DPG are not widely used in rubber glove production, and play only a minor role in rubber glove contact allergy. Most of the positive reactions to 1,3-DPG are probably false-positive, irritant reactions.

Adult↗
PubMed2003

Patch testing with components of water-based metalworking fluids.

Water-based metalworking fluids (MWFs) may cause both irritant and allergic contact dermatitis. Several well-known MWF allergens are available for patch testing, but considering the wide variety of possible components used in MWF, our diagnostic arsenal covers only a small part of potential allergens. We therefore selected 13 frequently used MWF components that might be sensitizers and had not yet been tested routinely. In 5 centres, 233 dermatitis patients with present or past occupational exposure to MWF were patch tested with this and other panels. Only 7 patients showed positive reactions to the study panel. Allergic reactions to the emulsifier diglycolamine [syn. 2-(2-aminoethoxy) ethanol] were seen in 5 patients, and 1 patient each reacted positively to 2-amino-2-ethyl-1,3-propanediol (AEPD) and methyldiethanolamine (MDEA). Clinical relevance of the reactions to diglycolamine was unequivocally proven by its presence in the MWF from the patients' workplace in 3 cases. Diglycolamine seems to be an important MWF allergen, independently from monoethanolamine and diethanolamine. A test concentration of 1% petrolatum (pet.) appears to be appropriate. The importance of AEPD and MDEA as MWF allergens still remains to be established. The lack of positive test reactions to the other MWF components tested may be due to their low-sensitizing potential or too low a patch test concentration being used.

Adult↗
PubMed2003

Contact allergy to ingredients of hair cosmetics in female hairdressers and clients--an 8-year analysis of IVDK data.

Not only hairdressers, but also their clients or home-users of hair cosmetic products may become sensitized to one of the product constituents. The present analysis addresses the question whether the pattern of sensitization is different in these 2 groups and includes female patients who consulted with the participating centres of the IVDK (http://www.ivdk.org) between 1995 and 2002, and in whom hair cosmetics have been considered as being causative of their contact dermatitis. Among these, 2 subgroups were identified: (i) patients, currently or previously working as hairdressers, diagnosed with occupational skin disease (H, n = 884) and (ii) patients who never worked as hairdressers, i.e. clients (C, n = 1217). Previous atopic eczema was twice as common among H, who were also much younger (median age 24 versus 46 in C). Analysis of sensitization frequencies and patterns showed the well-known decline of contact allergy to glyceryl monothioglycolate (GMTG) in H from 31.2% to 8.5%. Among the C, 1.7% were allergic to GMTG. Concerning p-phenylenediamine, a steady decline from 27.6% to 17.2% was observed in H, while no trend was found in C (12.6% and 16.6% in the first and the last 2-year period, respectively). Conversely, a very slight decline of p-toluenediamine sensitization was observed in H (from 29.5% to 24.8%), while at the same time a significant increase was noted in C (from 8.7% to 16.7%). A slighter increase was also noted with ammonium persulfate in C (3.1-6.8%), while the proportion of H sensitized remained largely constant at about 26%.

Adolescent↗
PubMed2003

Contact sensitization to N-(cyclohexylthio)phthalimide.

Previous reports revealed relative high sensitization rates to the rubber chemical N-(cyclohexylthio)phthalimide (CTP; CAS-No. 17796-82-6), but the relevance of positive reactions remained unknown. It was discussed whether the test concentration of 1% pet. needed to be changed. The German Contact Dermatitis Research Group (DKG) added CTP in 3 concentrations, i.e. 0.25% pet., 0.5% pet, 1% pet., to the rubber series. From June 1999 to December 2000, 1936 patients in 30 departments of dermatology were tested with CTP. Of the 56 patients with a positive test reaction (2.9%), 52 reacted to CTP 1% pet., 21 to CTP 0.5% pet., and 9 to CTP 0.25% pet. The reaction indices were about the same with all concentrations. 34 patients with a positive reaction to CTP 1% pet. did not react to the lower concentrations. The majority of these reactions are probably false-positive. With CTP 0.25% pet., however, the majority of true allergic reactions to CTP were missed. Analysis of population characteristics and concomitant sensitizations to other rubber chemicals led to the conclusion that a positive reaction to CTP 0.5% pet. was a good indicator of contact allergy to CTP. Thus, the DKG decided to continue patch testing with CTP 0.5% pet. in the rubber series. Manufacturers' information about the use of CTP seem to partly contradict the patients' characteristics seen in this study. So the relevance of positive CTP patch test reactions, and the causative exposures in patients with CTP allergy, still remain to be clarified.

Adult↗
PubMed2002

Type IV allergy in the food processing industry: sensitization profiles in bakers, cooks and butchers.

Data about the impact of allergic contact dermatitis in food processing occupations are scarce. The objective of this study was to identify the most frequent allergens and sensitization profiles in employees of the food processing industry. The results of patch testing performed in 873 bakers, cooks and butchers suspected of having occupational allergic contact dermatitis from 33 dermatological departments of the Information Network of Departments of Dermatology (IVDK) from 1992 to 1999 were analysed. A final diagnosis of allergic contact dermatitis was made in 213 patients (24.4%). Qualitative and quantitative differences in allergen profiles could be identified. Significantly higher sensitization rates were found in employees in the food processing industry, compared to the total test population, for nickel sulphate (22.4% versus 17.2%, p < 0.0005), thiuram mix (4.9% versus 2.6%, p < 0.0005), formaldehyde (3.5% versus 2.1%, p < 0.005) and Compositae mix (6.2%, p < 0.0005). Significantly lower sensitization rates were found for thimerosal (4.5% versus 6.9%, p < 0.05). For patch testing in food workers, we recommend the standard, the rubber and the Compositae series, as well as patients' own products according to the individual history.

Adult↗
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

Patch test reactions to Biobans in metalworkers are often weak and not reproducible.

Contact allergy to the industrial preservative group of Biobans has been reported in individual cases. We have performed a prospective study on 408 metalworkers who were tested with 6 different Biobans, formaldehyde and 5 other preservatives. Furthermore, retesting was performed after a time interval of 6 months to 4 years. The test results were also compared with those of the multicentric data provided by the Information Network of Departments of Dermatology in Germany and Austria (IVDK), particularly with regard to cross-reactivity between the various Biobans and formaldehyde. In 408 metalworkers 14 (3.4%) showed positive reactions to Biobans (2.2% P 1487, 2.0% CS 1246, 1.5% CS 1135), the majority being + reactions. On retesting 10 patients, the reactions were confirmed in only 2 cases (P 1487 and CS 1135). 4 patients showed positive reactions to 3 Biobans (P 1487, CS 1135, CS 1246), while 9 patients had only solitary sensitizations. Concomitant sensitization to formaldehyde was present in 5 out of 10 patients, being reproducible in 3 of them. In the IVDK data, sensitization prevalence in 3400 patients ranged from 1.8% (P 1487) to 0.8% (CS 1246). A high proportion of doubtful or irritant reactions as well as weak + reactions was observed. Cross-reactivity between the various Biobans was low, moderate agreement being calculated for CS 1135 and CS 1246 (kappa coefficient 0.43). The consensus pattern between formaldehyde and the tested Biobans was even lower. In conclusion, patch test reactions to Biobans are not rare among metalworkers but are often weak and not reproducible. Simultaneous reactivity to various Biobans and formaldehyde may be due to cross-reactivity or cosensitization from common exposure.

Allergens↗
PubMed2002

The spectrum of contact allergy in elderly patients with and without lower leg dermatitis.

BACKGROUND: There is a strong influence of lower leg dermatitis on the spectrum of allergic contact sensitivity in elderly patients. OBJECTIVE: To quantitatively assess the impact of this factor which confounds the age-related pattern of allergic contact sensitivity. METHODS: Stratified analysis of allergic contact sensitivity data collected between 1996 and 1999 in the 32 centres of the Information Network of Departments of Dermatology (three age groups: < or =60, 61-75, > or =76 years), both as crude and as directly standardised (for sex and leg dermatitis) proportions. RESULTS: Among the 36,070 patients tested with the German standard series, allergic contact sensitivity to neomycin, lanolin, cetostearylic alcohols, colophony, fragrance mix and balsam of Peru, among others, was (much) more common in the elderly, with proportions more or less affected by standardisation. CONCLUSION: The comparison of crude and standardised proportions provides evidence that allergic contact sensitivity to several allergens strongly depends not only on age itself, but on age-related and thus confounding co-morbidity.

Age Factors↗
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↗
PubMedDate not supplied

An attempt to improve diagnostics of contact allergy due to epoxy resin systems. First results of the multicentre study EPOX 2002.

Epoxy resin systems (ERSs) are a frequent cause of occupational allergic contact dermatitis. Sensitization occurs not only to the resins, but also to hardeners and reactive diluents. However, only a fraction of the ERS components currently in use are available for patch testing. With the multicentre study EPOX 2002, we attempted to improve diagnostics in this field by patch testing with components currently used in ERSs. During the first study period (October 2002 to July 2003), in addition to commercially available ERS patch test substances, 16 study substances (1 resin, 9 hardeners and 6 reactive diluents) were patch tested in 70 patients with suspected contact allergy due to ERSs and 22 patients with a prior positive patch test reaction to epoxy resin (ER) in the standard series. Most frequently, allergic reactions to ER based on diglycidyl ether of bisphenol A and F were observed (55.2% and 43.7%, respectively). Agreement between positive reactions to both resins, which can be explained by immunological cross-sensitization and/or coexposure, was substantial [Cohen's kappa 0.65 (95% CI: 0.49-0.80)]. Among the reactive diluents, 1,6-hexanediol diglycidyl ether (1,6-HDDGE) and 1,4-butanediol diglycidyl ether (1,4-BDDGE) were the most frequent allergens, with 19.5% and 18.4% positive reactions, respectively. Although agreement between positive reactions to 1,6-HDDGE and 1,4-BDDGE was even better than with the 2 resins, the sample size is considered too small to decide reliably whether 1,6-HDDGE alone could serve as a marker allergen for both. Allergic reactions to p-tert-butylphenyl glycidyl ether and to phenyl glycidyl ether (PGE) occurred in 11.5% of the patients tested, with only moderate agreement. All patients positive to cresyl glycidyl ether (6.8%) also reacted to PGE. Of the hardeners tested, m-xylylene diamine was the most frequent allergen (13.8%), followed by isophorone diamine (5.7%). No reactions were observed to several substances, the test concentration of which may have been too low and will be increased in the future.

Adolescent↗