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Biomedical subjects

J Geier

Publications and source records attributed to J Geier.

At least 37 records · Page 2Linked to original sources
PubMed2000

Patch testing with methyldibromoglutaronitrile.

BACKGROUND: The combination of methyldibromoglutaronitrile (MDBGN) and phenoxyethanol (PE) is widely used as a preservative in body care products. Sensitization rates to MDBGN have increased parallel to its increasing use in cosmetics, skin care products, and moist toilet paper since the early 1990s, whereas PE is obviously not a sensitizer. The optimum patch preparation for diagnosing a contact allergy to MDBGN is still a matter of debate. OBJECTIVE: This study was performed to assess an adequate patch test concentration for MDBGN/PE and MDBGN. METHODS: Based on previous results from other countries, the German Contact Dermatitis Research Group (DKG) performed parallel patch tests with MDBGN/PE 0.5% in petrolatum (pet.) and 1% pet. in 4,615 patients and with MDBGN 0.1% pet. and 0.3% pet. in 988 patients. The results of these tests, performed in routine patch testing, were collected and analyzed be the Information Network of Departments of Dermatology (IVDK). RESULTS: Comparing MDBGN/PE 0.5% pet. with 1.0% pet., the percentage of patients showing a positive test reaction increased from 2.3% to 3. 5% (P <.001), mainly because of an increase in weak positive reactions. The reaction index remained stable at 0.54. Comparing MDBGN 0.1% pet. with 0.3% pet., the percentage of patients with positive reactions increased from 1.4% to 3.3% (P <.001), and the reaction index decreased from 0.33 to -0.10. With the lower test concentration, 79% of the positive reactions were only +, with the greater concentration, this was true of 64%. CONCLUSION: Testing MDBGN/PE 1.0% pet. shows additional cases of contact allergy to MDBGN that would have remained undetected with MDBGN 0.5% pet. The greater test concentration seems to have no disadvantages in quality. The DKG decided to keep MDBGN/PE 1.0% pet. in the standard series. MDBGN 0.3% pet. leads to far more doubtful or irritant test reactions than MDBGN 0.1% and may produce false-positive patch test results. Therefore, the DKG recommends testing MDBGN 0.3% pet only in special cases.

Cosmetics↗
PubMed2000

Downward trend of sensitization to glyceryl monothioglycolate in German hairdressers. IVDK study group. Information Network of Departments of Dermatology.

BACKGROUND: Due to a high incidence of cases of (occupational) sensitization to glyceryl monothioglycolate (GMT), products containing this compound were withdrawn from the German market some 8 years ago. METHODS: We analyzed the data of the Information Network of Departments of Dermatology in Germany which included 1, 336 hairdressers who had been tested with GMT (1% in petrolatum) between 1992 and 1998. RESULTS: The proportion of hairdressers reacting positively to GMT fell from initially 45% in 1992 to less than 20% in 1997 and 1998. CONCLUSION: This most likely reflects the above-mentioned preventive action.

Allergens↗
PubMed2000

Allergic contact dermatitis in patients with anogenital complaints.

OBJECTIVE: Allergic contact dermatitis is a common anogenital disease. STUDY DESIGN: The results of patch testing performed on 1,008 patients evaluated for allergic anogenital contact dermatitis from 21 dermatologic departments in the Information Network of Departments of Dermatology (IVDK) from 1992 to 1997 were analyzed. RESULTS: A final diagnosis of allergic contact dermatitis was made in 351 patients (34.8%). Irritant contact dermatitis was diagnosed in 230 patients (22.8%) and other, nonspecified forms of perianal eczema in 228 patients (22.6%). The remaining cases were due to other distinct dermatologic diseases. Analyzing patch test data from this large group of patients showed that the allergen spectrum resembled that of all patients (54,000) tested from 1992 to 1997. However, dibucaine HCl ranked fourth among contact allergens in the study population. Positive reactions to (chloro-)-methyl-isothiazolinone and to benzocaine were observed more frequently among patients with anogenital complaints as compared to the total IVDK population (3.7% vs. 2.5% and 2.7% vs. 1.5%, respectively). In general, active agents of topical medications and popular remedies, preservatives and ointment bases appeared to cause allergic reactions most frequently. CONCLUSION: Patients with chronic anogenital diseases seem to have a high risk of becoming sensitized. For patch testing we recommend the standard series, dibucaine HCl, propolis, bufexamac and other ingredients from topical preparations according to the patient's history.

Adult↗
PubMed1999

The association between size of test chamber and patch test reaction: a statistical reanalysis.

A recent study by Brasch and co-workers reported on the association between size of test chamber and patch test reaction. The investigators interpreted their data on 495 patients as having conclusively shown that standard preparations of fragrance mix, wool wax alcohols, Kathon CG and formaldehyde led to more positive test reactions when large Finn Chambers were used for patch testing. We have scrutinized the statistical aspects of this study and conclude that the authors should have adopted a statistical approach suitable to analyse dependent samples. After explaining the correct methodological way of dealing with quadratic contingency tables formed by 2 dependent samples, we reanalyze the data accordingly and compare the results to those of the original paper. Based on this reanalysis, the conclusions are more complex: the reaction pattern for the fragrance mix and wool wax alcohols is significantly different between small and large test chambers; however, this discrepancy arises primarily from changing weak positive reactions with small chambers to strong positive reactions with large chambers. For formaldehyde, no relationship between chamber size and patch test reaction was found in the data, while for Kathon CG, statistical evidence is borderline that more positive test reactions are yielded by large test chambers than by small ones.

Adult↗
PubMed1999

Patch test reactions at D4, D5 and D6.

In this retrospective study, patch test reactions in 3 groups of patients were analysed, in order to obtain information on the best day for the 2nd patch-test reading after day 2 (D2), on the usefulness of additional readings after D3, and on the dependence of patch-test reactions at D4, D5, or D6 on allergen and/or patient characteristics. In the years 1990 to 1995, patch tests were routinely read at D3 and D4 in 1096 patients, at D3 and D5 in 1243 patients, and at D3 and D6 in 1136 patients. In all of the 3 groups, significantly more positive reactions diminished than appeared de novo from D3 to the later reading. Virtually identical results were observed in subgroups of patients formed by sex, age or atopy. However, men might possibly react more slowly than women on patch testing, showing more increasing than diminishing reactions in the D3/D4- and the D3/D5-comparison. Reactions to individual allergens showed wide differences in this connection. Neomycin sulfate, cobalt salts, and p-phenylenediamine can be characterized as slow allergens, with more reactions increasing than diminishing from D3 to the later readings. With fragrance mix and balsam of Peru, the opposite pattern occurred. In all subgroups of patients, and with most allergens, the gain in positive reactions was biggest when an additional reading was performed at D5. We conclude that for a single 2nd patch test reading after D2, D3 is the best day, and especially better than D4. If a 3rd reading is performed, it should be done at D5 to get the maximum information out of patch testing. However, this extends the test procedure to at least 1 day of the weekend.

Adult↗
PubMed1998

[Differentiated contact allergy lists serve in quality improvement].

Through cooperation between the German Contact Dermatitis Research Group (DKG) and the Information Network of Departments of Dermatology (IVDK), results of standardized patch tests performed by the participating centres are centrally recorded in Germany. For this study, data from 24 departments of dermatology (19678 patients) were evaluated retrospectively and separately for 1995 and 1996. With decreasing frequency, nickel, fragrance mix, balsam of peru, and thimerosal yielded positive reactions most often; surprisingly high numbers of positive reactions were also seen with amerchol L-101 and palladium. Differentiated lists of allergens were compiled for 1995, referring to subgroups of patients (defined by gender, age, localization of eczema, geographical region, occupation, sensitization) and particular problems. In men, percentages of positive reactions were markedly lower for nickel, fragrance mix and balsam of peru than in women. Younger patients reacted more often to thimerosal and older ones to topical medical preparations. Medical allergens were also often positive in patients with leg eczema, whereas occupational allergens were found more frequently in patients with hand eczema. A comparison of positive reactions obtained in distinct geographical regions was problematic because of differences between test populations. The spectrum of allergens found in office workers was similar to that of the whole test population. Patients with positive reactions to nickel and fragrance mix had more positive reactions to unrelated allergens than the total test population. Sex- and age-adjusted frequencies of sensitization revealed a decrease in reactions to nickel and an increase in reactions to mercury allergens from 1995 to 1996. The clinical relevance of mercury reactions was often not apparent. Differentiated lists of allergens can be used to improve the quality of diagnostic and prophylactic procedures in allergic contact dermatitis.

Adolescent↗
PubMed1998

Patch testing with preservatives, antimicrobials and industrial biocides. Results from a multicentre study.

Preservatives are biologically reactive substances, and their allergenic potential has been known for a long time. This study examined the role of different preservatives in a large number of patients with suspected allergic contact dermatitis. Patch test data and data from the patients' history were collected from the 24 departments participating in the Information Network of Departments of Dermatology from 1 January 1990 to 31 December 1994. Patch test data from 28,349 patients tested with preservatives of the standard series (SS), from 11,485 patients tested additionally with a preservative series (PS), and from 1787 patients tested with an industrial biocide tray (IB) were evaluated. Sensitization rates (standardized) of the SS preservatives were all > 1%, with thiomersal rating highest (5.3%), the parabens lowest (1.6%), and the remainder (chlormethylisothiazolinone/methylisothiazolinone, formaldehyde and methyldibromoglutaronitrile/phenoxyethanol (MDBGN/PE)) in the range of 2%. The most important allergens of the PS were, in women, alkylaminobenzoate (contained in milking fat) (2.5%), MDBGN/PE (2.2%), benzalkonium chloride (1.8%), chloracetamide (1.4%), diazolidinyl urea (1.3%), octylgallate (1.2%) and Bronopol (1.1%). In men rates differed only with regard to alkylaminobenzoate (0.9%). Patients tested with the IB series reacted most often to methylene-bis-thiocyanate (5%), but with a reaction index of -0.7, many reactions were most probably false positives. A further seven preservatives, mostly formaldehyde-releasers used in cutting fluids, gave sensitization rates of between 1% and 3%. Glutaraldehyde, not contained in the series but often tested additionally, showed a remarkable increase in sensitization during the study period. Health care personnel were frequently affected. Altogether, this study identified areas of concern within the different groups of preservatives. The overall impact of most of the preservatives on public health seems to be low, but for diagnostic reasons preservatives must be included in patch test series.

Adult↗
PubMed1998

Contact allergies in healthcare workers. Results from the IVDK.

Healthcare workers often suffer from occupational skin disease frequently caused by allergic sensitization. Therefore the patch-test results and important patient history items of 31,849 patients recorded between 1992 and 1995 in the 24 allergy departments participating in the Information Network of Departments of Dermatology (IVDK) were evaluated. Significantly increased sensitization rates common to the healthcare sector as a whole were found for the vaccine preservative thiomersal (12.6% vs. 4.9%), the surface and instrument disinfectants glutardialdehyde (9.9% vs. 2.6%), formaldehyde (3.6% vs. 2.1%) and glyoxal (4.2% vs. 1.4%), and for the compounds of the thiuram mix (6.7% vs. 2.6%) present in protective gloves. Formaldehyde seems to lose its importance, but glyoxal must be added to the list of occupational allergens in the healthcare sector. In addition, occupation-specific sensitization was observed, with fragrances in massage therapists (16.1% vs. 10.6%) and nurses (13.8% vs. 11.4%), as well as with methacrylates in dental technicians. The often assumed importance of drugs as type-IV allergens was not confirmed, at least in terms of quantity. The identification of subgroups of increased risk and of occupation-specific allergens could be the basis of targeted preventive action in the healthcare sector.

Adult↗
PubMed1998

Genotype and phenotype of N-acetyltransferase 2 (NAT2) polymorphism in patients with contact allergy.

We investigated whether patients with contact allergy differed from non-contact-allergic, non-atopic controls with regard to genotype and phenotype of the polymorphic enzyme N-acetyltransferase 2 (NAT2). 55 contact-allergic patients recruited from the Information Network of Departments of Dermatology (IVDK) were compared to 85 controls from among local health care personnel. NAT2 activity was calculated from HPLC analysis of the ratio of the caffeine metabolites 5-acetylamino-6-formylamino-3-methyluracil (AFMU) and 1-methylxanthine (1MX) in the urine. NAT2 genotype was determined by polymerase chain reaction (PCR). A statistically significantly increased proportion of rapid acetylators was found in contact-allergic patients. This may have 2 possible implications: acetylation may enhance contact sensitization; or NAT2 status may be a genetic marker for contact sensitizability.

Acetylation↗
PubMed1997

National rates and regional differences in sensitization to allergens of the standard series. Population-adjusted frequencies of sensitization (PAFS) in 40,000 patients from a multicenter study (IVDK).

Sensitization rates to contact allergens vary between centers and are influenced by sex and age. Eliminating the latter 2 factors by standardization of data by age and sex, the present analysis addresses possible differences between centers remaining after elimination of these confounders, and analyzes other factors which might influence rates, e.g., the MOAHL index. Overall standardized rates were well within the range reported in previous studies and may be regarded as representing the rates of the "patch test population" in Central Europe (e.g., nickel sulfate 12.9%, fragrance mix 10.5%, balsam of Peru 7.3%, thimerosal 5.6%). For this analysis, data of those departments which contributed more than 2000 patients, or of those with extreme proportions concerning sex, age and occupational cases were selected. Patients from these 10 departments differed considerably with regard to the items of the MOAHL index and with regard to standardized rates. The items of the MOAHL index proved to be suitable for describing different patch test populations and for explaining some differences between centers. Only 'atopic dermatitis' seems to have little influence on (standardized) rates. Face dermatitis is not yet represented in the MOAHL index, but should be included, together with age > 40 years, in an extended index (acronym: MOAHLFA). Regional allergen exposure (with striking differences between East Germany, West Germany and, to a lesser extent, Austria) seems to have a great influence on the sensitization pattern observed in a department. In addition, sociological factors may influence sensitization rates, which is exemplified by high rates of nickel allergy in a socially defined subgroup. Future studies should focus on these factors, as well as on factors concerning patch test practices and quality control.

Adult↗
PubMed1997

Patch test results in schoolchildren. Results from the Information Network of Departments of Dermatology (IVDK) and the German Contact Dermatitis Research Group (DKG)

Our aim was to explore the current spectrum of contact allergens in schoolchildren, as a basis for diagnosis and prevention of allergic contact dermatitis. Results of patch tests in children 6-15 years old, performed in the years 1990-1995 by 22 centres of the German Contact Dermatitis Research Group and filed by the Information Network of Departments of Dermatology, were analysed and evaluated retrospectively, including epidemiologic data. Children with positive tests (62 out of 156 boys and 108 out of 260 girls tested) had a higher frequency of allergic contact dermatitis and a lower frequency of atopic dermatitis than patch test negative ones. 16 distinct allergens elicited positive reactions in > or = 1% of the children tested. Reactions to nickel sulfate occurred in 15.9% of all children tested, but in 25.0% of girls 14/15 years old, and in only 4.5% of boys 6-13 years old. Double-sensitizations with cobalt salts, potassium dichromate and palladium were seen. Mercury compounds were found in 2nd place (thimerosal: all children: 11.3%; 6-13 years old: 14.3%; 14/15 years old: 8.0%), followed by fragrance allergens. We conclude that contact allergy in children is related to their sex and age. Prophylaxis against nickel, mercury, and fragrance allergy needs to be improved. A shortened standard series may be sufficient for testing children.

Adolescent↗
PubMed1996

[Dental materials--problem substances in allergologic diagnosis? I: Analysis of test results in patients with mouth mucosa/dental material problems].

Patch testing as a part of the diagnostic evaluation of patients suffering from oral mucosal complaints or with symptoms where dental materials are suspected to be the cause is hampered by numerous difficulties. The ingredients of denture materials as well as their liberation in the oral cavity are often unknown. Contact with many of the potential ingredients of denture materials can occur on other occasions, as well, thus making it difficult to find out where the patient has acquired his or her sensitization. The special morphological and immunological situation in the oral mucosa may produce tolerance of substances which evoke a positive patch test reaction on the skin of the back. This paper introduces the possible spectrum of allergens in these patients and discusses the difficulties in the assessment of the relevance of positive patch test reactions. From August 1992 to July 1994, 756 patients with complaints of the oral mucosa and/or suspected contact allergy to denture materials were patch tested in the departments of dermatology joining the Information Network of Departments of Dermatology in Germany (IVDK). Among these patients, women were overrepresented, while individuals with atopic dermatitis were underrepresented. The allergen spectrum included amalgam, mercury compounds, gold salts, palladium chloride and methyl methacrylate. However, the epidemiological value of these data is limited. A second part of this paper will review the various groups of allergens.

Adult↗