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Biomedical subjects

A Schnuch

Publications and source records attributed to A Schnuch.

At least 19 recordsLinked to original sources
PubMed2003

[Severe allergic contact dermatitis with generalized spread due to bufexamac presenting as the "baboon" syndrome].

HISTORY AND CLINICAL FINDINGS: A 48-year-old woman presented with acute, pruritic, sharply demarcated, erythematous, maculopapulous exanthem in the anogenital area with disseminated maculae over the back. Several days before, the patient had applied as topical treatment a bufexamac-containing ointment to the anal region. INVESTIGATIONS: The patch test showed an allergic test reaction to bufexamac. DIAGNOSIS: The case presents a serious allergic contact dermatitis with generalization, imitating a baboon syndrome, unequivocally linked to the previous topical treatment. CONCLUSION: During the last 10 years allergic reactions to bufexamac have increasingly been reported, sometimes with erythema multiforme-like reactions. Because of the high rate of sensitization, the serious clinical course of bufexamac allergy and the insidious symptoms of this side effect, sometimes mimicking the disease to be treated, the substance should be used neither for proctological nor for dermatological diseases, even more as these patients are considered to be at high risk of developing allergic contact dermatitis because of the abnormal skin barrier. Considering the data presented, the use of bufexamac should be critically reassessed.

Administration, Topical↗
PubMed2003

Risk factors for contact allergy to nickel - results of a multifactorial analysis.

To quantify the independent impact of potential risk factors for nickel contact allergy (NCA), a multifactorial Poisson regression analysis of standardized anamnestic and patch test data (with nickel sulfate, 5% in petrolatum) was performed, comprising 74 940 patients assessed in the 33 German and Austrian contact dermatitis units of the Information Network of Departments of Dermatology (IVDK) between 1992 and 2000. NCA was observed in 15.5% patients. Female sex was the strongest risk factor (prevalence ratio 3.74, 95% CI: 3.51-3.98). Risk increased monotonically and significantly with decreasing age. Atopic dermatitis was not a risk factor. The year of patch test had no influence on NCA risk. Significant variation of risk between occupations was observed. In conclusion, our multifactorial analysis was able to quantify the impact of established risk factors and additionally address other, e.g. occupational, factors yet unidentified.

Adult↗
PubMed2002

The preservative iodopropynyl butylcarbamate: frequency of allergic reactions and diagnostic considerations.

The preservative iodopropynyl butylcarbamate (IPBC) (0.1% in petrolatum) was tested in 4883 consecutive patients for 18 months between January 1998 and June 1999. With regard to the MOAHLFA-Index, the study population comprised 37% males; 17% with occupational and 19% with atopic dermatitis; 31% with hand, 10% with leg and 17% with face dermatitis; 61% were age 40 and above. According to readings at D3, 0.3% were allergic to IPBC, with 14 + and 2 + + reactions. Doubtful or irritant reactions occurred twice as frequently. Patients exposed for 24 h (n = 1814) reacted less frequently (0.1%) than the remaining patients exposed for 48 h (0.5%). Considering the possibility that a certain proportion of + reactions could be false positive, the reaction pattern was evaluated. More than 80% of the positive reactions displayed a crescendo or plateau time pattern. Furthermore, 18 of 43 doubtful reactions (?) appeared as late as D3 (thus, these could be false negative), whereas the majority of doubtful reactions occurred earlier and displayed a decrescendo pattern (corresponding to a typical irritant pattern). In conclusion, the large proportion of '?' reactions may be due not only to the irritant potential of the substance, but also to test concentrations not being high enough to elicit an allergic reaction. We propose that higher concentrations of IPBC (0.3%) should be evaluated in a study also addressing suitable validation tests like ROAT or PUT.

Adult↗
PubMed2002

Epidemiology of contact allergy: an estimation of morbidity employing the clinical epidemiology and drug-utilization research (CE-DUR) approach.

Clinical epidemiology (CE) is considered unable to estimate morbidity concerning either contact sensitization (CS) or allergic contact dermatitis (ACD) at the population level. Drug-utilization research (DUR) methods estimate the morbidity of suitable diseases based on prescription data for disease-specific drugs. Our objective was to estimate population figures for incidence and prevalence of ACD and CS based on sales data for patch test material in Germany and on patient data from the Information Network of Departments of Dermatology (IVDK). Approximately 600000 standard series are sold per year in Germany, according to the 2 main manufacturers. This raw sales figure was corrected for certain effects (discarded preparations, proportion of formerly patch-tested patients, proportion of patients with ACD seeking medical advice) to obtain an estimate of the denominator of patients eligible for patch testing annually, and combined with patch test results from the Information Network of Departments of Dermatology (IVDK). In 17.8% (of 9266 IVDK patients) ACD was established. Extrapolated to the general population, an incidence of ACD of between 1.7 and 7 per 1000 per year was estimated, depending on whether conservative or more liberal assumptions concerning the above effects were made. Of 78067 IVDK patients tested between 1992 and 2000, 46.8% had at least 1 positive reaction (+ to + + +), and 22.7% had at least 1 stronger positive reaction (+ + or + + +). The 9-year prevalence of CS was estimated to lie between 4.0% and 16.6% for the first outcome, and between 2.0% and 8.1% for the second. Concerning single allergens, 1.9-4.5 million individuals are probably sensitized to nickel, and 1.4-3.4 million to fragrance mix among the German population of 82 million inhabitants. The morbidity data found in this study are in good accordance with data from population-based epidemiological studies. In comparison to these, the CE-DUR approach seems to be an economically feasible method to estimate continuously the population impact of ACD and CS.

Allergens↗
PubMed2002

When should a substance be designated as sensitizing for the skin ('Sh') or for the airways ('Sa')?

In the List of MAK and BAT Values compounds are designated with 'Sa' ('sensitizing for the airways') or 'Sh' ('sensitizing for the skin') if, according to scientific evidence, they are allergens. Mainly based on suggestions by a WHO working group and based on our own experience, extended criteria have been elaborated by the working group 'skin and allergy' of the Commission of the Deutsche Forschungsgemeinschaft for the Investigation of Health Hazards of Chemical Compounds in the Work Area, which are presented in this article. They serve as guidelines for deciding which substances have to be labelled 'Sa' and 'Sh', respectively, for the prevention of sensitization and subsequent allergic diseases in workers. Although in some special cases their strict application may not be deemed necessary or possible, the proposed new criteria should be used to make the procedure of classification of substances: 1) more rational, 2) more consistent, 3) more comprehensible, and 4) more transparent. This paper informs readers working scientifically or administratively in this field and invites a critical discussion of the issue.

Allergens↗
PubMed2001

Another look at seasonal variation in patch test results. A multifactorial analysis of surveillance data of the IVDK. Information Network of Departments of Dermatology.

There is conflicting evidence concerning seasonal variability of patch test results and no evidence concerning the influence of season on weak-positive, possibly false-positive, irritant reactions, which was analysed in the present study. Data collected in the German Information Network of Departments of Dermatology (IVDK) 1992 to 1997 were combined with external environmental data on temperature and absolute humidity in Germany, and bivariate as well as logistic regression analyses performed concerning the association between reactivity to selected allergens and air temperature and absolute humidity on the respective days of patch testing. Between 39,239 and 41,629 patients had been tested with the 4 allergens considered here. Only formaldehyde exhibited a distinct increase in questionable or irritant as well as weak-positive reactions associated with dry, cold weather. Methylchloroisothiazolinone/methylisothiazolinone and lanolin alcohol showed only a weak, and epoxy resin no, association with climatic conditions. The results indicate that weak-positive reactions, at least to formaldehyde as a prototype of an allergen which is at the same time a marginal irritant, may sometimes be irritant rather than allergic. Patients showing these should be re-tested to improve the poor reproducibilty observed with this allergen.

Climate↗
PubMed2001

Associated positive patch test reactions to standard contact allergens.

BACKGROUND: Patch testing with a standard allergen series often yields positive reactions to more than 1 allergen in a patient. OBJECTIVE: To identify all significantly associated pairs of positive reactions and to assess their relation to the strength of the reactions and to the irritative potential of the allergens. METHODS: Based on the filed data of 57,822 patients, associations between positive reactions to 2 different allergens were quantified with odds ratios. Statistical methods included Fisher's exact test, the Bonferroni adjustment to account for the effect of multiple testing, and the Spearman rank correlation. RESULTS: Out of the 32,779 patients with complete readings of 24 standard allergens, 7,501 had shown more than 1 positive reaction. Statistically significant associations were detected for 166 out of the 276 possible different combinations of 2 distinct positive reactions, including combinations that had not been identified before. Patients with a strong reaction or a positive reaction to an allergen with a high irritative potential tended to have additional positive reactions to further allergens more often than others, but the number of significant associations was not dependent on these parameters. CONCLUSION: There are more significant associations that have to be taken into account for patch testing than has been known so far. Although irritation can favor a higher number of positive reactions, significant associations of positive reactions to distinct allergens are probably caused by other mechanisms that require further analyses.

Adult↗
PubMed2001

Glyoxal is an important allergen for (medical care) cleaning staff.

While disinfection is essential in medical practice, it carries the risk of serious adverse effects, including allergic contact dermatitis. To assess the current importance of glyoxal [CAS 107-22-2] as occupational allergen, a retrospective descriptive analysis of records of an occupational dermatitis clinic in Osnabrück and of national surveillance data of the Information Network of Departments of Dermatology (IVDK) in Germany and Austria was performed. Of 189 highly selected patients with occupational dermatitis tested with glyoxal (1% in water or, as trimer, 1% in petrolatum) in Osnabrück, 11 had positive reactions to glyoxal, which were occupationally relevant in 9 cases. Causative occupations included mainly nursing and room cleaning. In a less selected population of 2626 additional patients tested in other centres of the IVDK, 40 further positive reactions to glyoxal were observed. Concomitant sensitisation to glutardialdehyde and formaldehyde, respectively, was frequently observed. In conclusion, glyoxal should be tested in all patients with contact dermatitis working in occupations with possible exposure to respective disinfecting/cleaning agents.

Adult↗
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↗