Search PubMed⌕ Search

Biomedical subjects

A Schnuch

Publications and source records attributed to A Schnuch.

At least 55 records · Page 3Linked to original sources
PubMed2001

Association between occupation and contact allergy to the fragrance mix: a multifactorial analysis of national surveillance data.

OBJECTIVES: To assess the role of potential (occupational) risk factors for fragrance contact allergy (FCA). Most studies assessing the range of contact sensitisation in various clinical populations found the fragrance mix, a good screening tool for the detection of FCA in general, to be one of the leading allergens. The role of occupational exposure to fragrances is, however, yet unclear. METHODS: Firstly, crude analyses of the prevalence of FCA in various occupational fields including all 57,779 patients patch tested in the participating centres of the Information Network of Departments of Dermatology (IVDK) between January 1992 and December 1998. Secondly, a multifactorial Poisson regression analysis of these patients, including several potential risk factors. RESULTS: (a) The proportion of patients with FCA varied greatly between different occupational groups from 2.5% to 17.4%, (b) the highest occupational risk of FCA was associated with work as a masseur or physiotherapist, metal furnace operator, potter or glass maker etc, or geriatric nurse, (c) non-occupational factors that influenced risk of FCA included atopy, female sex, several sites, in particular the axillae, and increasing age. CONCLUSIONS: Occupations with a high risk of FCA were identified as targets of preventive action--that is, the substitution of scented products with fragrance free materials with which to work (skin disinfectants, cleaning solutions, personal care products) wherever possible.

Adult↗
PubMed2000

Homozygous gene deletions of the glutathione S-transferases M1 and T1 are associated with thimerosal sensitization.

OBJECTIVE: Thimerosal is an important preservative in vaccines and ophthalmologic preparations. The substance is known to be a type IV sensitizing agent. High sensitization rates were observed in contact-allergic patients and in health care workers who had been exposed to thimerosal-preserved vaccines. There is evidence for the involvement of the glutathione system in the metabolism of thimerosal or its decomposition products (organomercury alkyl compounds). Thus detoxification by polymorphically expressed glutathione S-transferases such as GSTT1 and GSTM1 might have a protective effect against sensitization by these substances. METHODS: To address this question, a case control study was conducted, including 91 Central European individuals with a positive patch-test reaction to thimerosal. This population was compared with 169 healthy controls and additionally with 114 individuals affected by an allergy against para-substituted aryl compounds. The latter population was included in order to test whether possible associations were due to substance-specific effects, or were a general feature connected with type IV immunological diseases. Homozygous deletions of GSTT1 and GSTM1 were determined by polymerase chain reaction. RESULTS: Glutathione S-transferase M1 deficiency was significantly more frequent among patients sensitized to thimerosal (65.9%, P = 0.013) compared with the healthy control group (49.1%) and the "para-compound" group (48%, P = 0.034). Glutathione S-transferase T1 deficiency in the thimerosal/mercury group (19.8%) was barely elevated versus healthy controls (16.0%) and the "para-compound" group (14.0%). The combined deletion (GSTT1-/GSTM1-) was markedly more frequent among thimerosal-sensitized patients than in healthy controls (17.6% vs. 6.5%, P = 0.0093) and in the "para-compound" group (17.6% vs. 6.1%, P =0.014), revealing a synergistic effect of these enzyme deficiencies (healthy controls vs. thimerosal GSTM1 negative individuals, OR = 2.0 [CI = 1.2-3.4], GSTT1-, OR = 1.2 [CI = 0.70-2.1], GSTM1/T1-, OR = 3.1 [CI = 1.4-6.5]). CONCLUSIONS: Since the glutathione-dependent system was repeatedly shown to be involved in the metabolism of thimerosal decomposition products, the observed association may be of functional relevance.

Adolescent↗
PubMed2000

Increase in sensitization to oil of turpentine: recent data from a multicenter study on 45,005 patients from the German-Austrian Information Network of Departments of Dermatology (IVDK).

Contact allergy to oil of turpentine was reported to have become rare. However, the evaluation of standardized data of 45,005 patients tested 1992-1997 in 30 Dermatological Centers associated with the German-Austrian Information Network of Departments of Dermatology (IVDK) showed an increase in positive patch test reactions to turpentine from 0.5% during the years 1992-1995, up to 1.7% in 1996 and 3.1% in 1997. In particular, 17,347 patients tested in 1996-1997 were evaluated in detail by comparing 431 individuals with positive patch test reactions with the rest of the group found negative to turpentine. Using the so-called MOAHLFA index, the following characteristics were shown. Turpentine allergy (a) was found to be significantly less frequent in men and in patients with occupational dermatitis, (b) showed no difference in its association with atopic dermatitis, (c) patients with turpentine allergy had significantly less symptoms of the hands, more symptoms of the legs or in the face and (d) were significantly more often aged over 60 years. Also, patients sensitized to turpentine had increased rates of additional sensitizations. The definite reason for the increase in turpentine sensitization in the population tested here is not clear. Therefore, a detailed exposure analysis is necessary; the new increase in turpentine allergies may be due to popular topical remedies or household chemicals.

Adult↗
PubMed2000

N-acetyltransferase 1 and 2 polymorphisms in para-substituted arylamine-induced contact allergy.

Sensitization to arylamines such as p-phenylenediamine is frequently diagnosed in patients with allergic contact dermatitis. Reactive metabolites of p-phenylenediamine might be produced in the skin by O-acetylation of N-hydroxylamines catalysed by local N-acetyltransferases (NATs). In this study, we tested whether genetic polymorphisms of NATs, which are known to affect enzyme activity, may influence the susceptibility to para-substituted arylamine-induced contact eczema. Using polymerase chain reaction and restriction enzyme analysis, the distribution of polymorphisms of NAT1 and NAT2 was investigated in 88 patients sensitized to para-substituted aryl compounds and 123 healthy controls. NAT2 rapid acetylators, i.e. carriers of the NAT2*4 wild-type allele, were more common in the contact allergy (44%) than in the healthy control group [30%; P = 0.042, odds ratio 1.9 (95% confidence interval, CI 1. 05-3.27)]. Slow acetylators carrying the NAT2*5b/2*6a genotype were significantly less frequent among patients [13% vs. 38% in controls; P = 0.009, odds ratio 0.39 (95% CI 0.19-0.78)]. The carriage rate of the NAT1*10 allele, which is supposed to encode for a rapid NAT1 phenotype, was not significantly different between patients and controls [43% vs. 36%; odds ratio 1.5 (95% CI 0.88-2.68)]. Interactions between NAT2*4 and NAT1*10 were suggested by the increased frequency of the NAT2*4/NAT1*10 haplotype in patients (27%) compared with controls [15%; P = 0.039, odds ratio 2.1 (95% CI 1.04-4.04)]. As the NAT1 and NAT2 encoding genes are located in close proximity on chromosome 8p22, the latter finding could at least partly be due to genetic linkage. In fact, a linkage disequilibrium between NAT2*4 and NAT1*10 was observed in the contact allergy (P = 0.0025) and in the control group (P = 0.042). Our data indicate an association between the NAT2*4/NAT1*10 haplotype and contact sensitization to para-substituted aryl compounds. Therefore, acetylation may either enhance contact sensitization or NAT2*4 and NAT1*10 might be linked to an unknown susceptibility factor.

Adolescent↗
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↗
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↗