Jochen Brasch

The European baseline series in 10 European Countries, 2005/2006 : results of the European Surveillance System on Contact Allergies (ESSCA)

Background: Continual surveillance based on patch test results has proved useful for the identification of contact allergy.

Reproducibility of patch tests: A multicenter study of synchronous left- versus right-sided patch tests by the German Contact Dermatitis Research Group

BACKGROUND The efficiency and reproducibility of patch tests remain controversial. OBJECTIVE Our purpose was to determine the efficiency and reproducibility of patch tests and to identify factors influencing these features. METHODS We double-tested 1285 patients concomitantly with 10 standard allergens by manually filled test chambers. Additional information was obtained from all patients with a standardized protocol. RESULTS Patch test efficiency was good (> or = 0.94) with all 10 allergens. In contrast, nonreproducibility of patch tests was strongly allergen dependent, ranging from 0.2 for nickel sulfate to 0.6 for formaldehyde. The likelihood of nonreproducible allergic reactions increased when more than four positive reactions were seen at the same time, and with another positive reaction located in close proximity to an allergic reaction. Sex and age of patients, atopy, dermatitis at distant sites, sleeping habits, and the time of allergen exposure (24 or 48 hours) did not affect the rate of nonreproducible results. CONCLUSION To increase patch test reproducibility, specific preparations of patch test allergens need to be improved. Furthermore, amplification effects by synchronous neighboring positive reactions should be excluded.

Patch testing with contact allergens

One-year prevalence of contact dermatitis in the general population is 7%. 15 to 20% of the general population are sensitized to one of the common allergens [1, 2]. Contact dermatitis is the subject of a current guideline of the German Dermatologic Society (Deutsche Derma tologische Gesellschaft, DDG) [3]. The patch test is the only instrument suitable for routine diagnostics to prove sensitization to a substance causing an allergic contact dermatitis. Synchronous reproducibility ranges from 60 to 90 %, depend ing on test method and allergen [4, 5].

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 ≥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.

Oral lichenoid reactions associated with amalgam: improvement after amalgam removal

Background  The pathogenetic relationship between oral lichenoid reactions (OLR) and dental amalgam fillings is still a matter of controversy.

Current patch test results with the European baseline series and extensions to it from the 'European Surveillance System on Contact Allergy' network, 2007-2008

Background. The pattern of contact sensitization to the supposedly most important allergens assembled in the baseline series differs between countries, presumably at least partly because of exposure differences.

The reaction index: a parameter to assess the quality of patch test preparations.

Allergic contact dermatitis might have been caused by epoxy resin 6360, the non-bisphenol-A-type epoxy resin. The hardener GY-051 and HD-electrician specialized filling powder might also have been allergens. But many of the skin and lip lesions might have been due to the other epoxy resin and to additives. These would have been mild chronic irritant reactions, such as the nail changes. It has already been reported that contact dermatitis from epoxy Contact Dermatitis 1992: 27: 203

Integrity of the permeability barrier regulates epidermal Langerhans cell density.

Summary Previous studies have shown that barrier requirements regulate epidermal liquid and DNA synthesis. In the present study, we examined the possibility that the integrity of the permeability barrier influences epidermal Langerhans cells involved with the immune response. Barrier disruption was achieved by treatment of human skin with acetone, sodium dodecylsulphate (SDS), or tape stripping, until a 10–20‐fold increase in transepidermal water loss was achieved. Serial biopsies were performed 6–168 after treatment, and Langerhans cells were complexed with anti‐CD1a (Leu6) or S‐l00 antibodies, and visualized with an immunoperoxidase technique. Acetone treatment resulted in an increase in epidermal Langerhans cell density, reaching a maximum of 94% over control (P < 0.01) by 24 and 48 h post‐treatment. Following SDS treatment or tape stripping, epidermal Langerhans cell density was increased by 100 and 175% (P < 0.01), respectively. There was a linear correlation between the degree of barrier disruption and the increase in epidermal Langerhans cell density. Studies with the Ki‐S3 proliferation‐associated nuclear antigen revealed a two‐ to threefold increase in epidermal proliferation after barrier disruption. The time curves of the increase in Langerhans cell density and the increase in epidermal proliferation were similar, suggesting that there was a coordinate regulation. In contrast with our previous studies employing patch test reactions to allergens or irritants, disruption of barrier function neither resulted in an increased dermal Langerhans cell density, nor influenced T lymphocytes (CD3+. Leu4+). Macrophages (KiM8+), ICAM‐1 or ELAM‐1 expression in the skin. In addition, barrier disruption did not result in either dermal inflammation or epidermal spongiosis. In summary these findings support our hypothesis that the permeability barrier influences epidermal Langerhans cell density, which is involved in maintaining an immunological barrier.

Polysensitization and increased susceptibility in contact allergy: a review.

Genetic factors presumably play a role in contact allergy (CA). There is, however, a lack of conclusive evidence from clinical studies. This may be on account of the strongly competing or modifying impact of exogenous factors, namely the potency of allergens and the intensity of exposure, and the fact that – in principle – everybody can be sensitized. Regarding phenotype, in contrast, polysensitization (PS) seems to indicate a subset of individuals at greater risk. In human sensitization experiments with dinitrochlorobenzene, induction was facilitated in PS, and elicitation enhanced. Recent clinical epidemiological data, taking confounders for PS, such as age, sex, and other skin diseases into account, demonstrated the following: (i) PS was the greatest risk factor to be sensitized to a number of (even weak) index allergens, indicating higher susceptibility on the level of induction; (ii) patch test reactions in PS patients were generally stronger indicating higher susceptibility on the level of elicitation. These findings are complemented by reports on polymorphisms of TNF‐α and IL‐16 in PS patients. Future studies on the genetics of CA should be performed in subgroups with PS, focussing on polymorphisms relevant for CA‐specific and nonspecific (inflammatory) processes.

Evaluation of patch test results by use of the reaction index. An analysis of data recorded by the Information Network of Departments of Dermatology (IVDK)

Results of patch tests performed in 15.553 patients by IS dermatological department (members of the German Contact Dermatitis Research Group) and recorded by the Information Network of Departments of Dermatology (IVDK) were analysed by comparing recently defined reaction indices (RIs). The RIs studied were calculated from the numbers of allergic (a), questionable (q), and irritant (i) reactions (RI = (a‐q‐i/(a+q+l)), which were obtained using 13 European standard allergens. RIs were calculated for all patients and for separate subgroups defined by age, sex, history of atopic dermatitis time of allergen exposure (1 versus 2 days), and lime of patch test reading (2 or 3 days after allergen application), Higher RIs were consistently obtained when patch tests were applied for 1 day, as compared to 2 days. Readings at 3 days after allergen application resulted in higher RIs than readings after 2 days. In contrast, sex, age, and history of atopic dermatitis of patients were not found to have LI consistent influence on the RIs. We suggest that reading after 3 days should be obligatory, and that allergen exposure for 1 day instead of 2 days might make patch test evaluation easier. These suggestions need to be substantiated by data on clinical relevance.