In the planning and implementation of measures aimed at preventing occupational contact dermatitis, the focus should be on the identified high-risk occupational groups and the most common occupational allergies.

Continuous surveillance of contact allergy based on network data offers the identification of time trends or persisting problems, and thus enables focussing in-depth research (subgroup analyses, exposure analysis) on areas where it is needed.

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. Objectives. To describe the prevalence of contact sensitization to allergens tested in consecutive patients in the years 2007 and 2008, and to discuss possible differences. Methods. Data from the 39 departments in 11 European countries comprising the European Surveillance System on Contact Allergy network (http://www.essca-dc.org) in this period have been pooled and analysed according to common standards. Results. Patch test results with the European baseline series, and country‐specific or department‐specific additions to it, obtained in 25 181 patients, showed marked international variation. Metals and fragrances are still the most frequent allergens across Europe. Some allergens tested nationally may be useful future additions to the European baseline series, for example methylisothiazolinone, whereas a few long‐term components of the European baseline series, namely primin and clioquinol, no longer warrant routine testing. Conclusions. The present analysis points to ‘excess’ prevalences of specific contact sensitization in some countries, although interpretation must be cautious if only few, and possibly specialized, centres are representing one country. A comparison as presented may help to target in‐depth research into possible causes of ‘excess’ exposure, and/or consideration of methodological issues, including modifications to the baseline series.

Prolonging strictly exclusive breastfeeding for > or =9 months was not helpful in atopy prevention, instead, it was associated with increased atopic dermatitis and food hypersensitivity symptoms in childhood.

Allergic contact dermatitis caused by to epoxy products cannot always be diagnosed by the use of commercial test substances. Workplace products need to be tested.

Early markers of atopic predisposition are needed for targeting allergy preventive measures to high‐risk infants. An elevated cord serum immunoglobulin E (CS‐IgE) level is considered a risk factor for subsequent allergy in childhood. However, the previous studies have not assessed the predictive value of CS‐IgE in a follow‐up extended to adulthood. We aimed at clarifying whether CS‐IgE is useful in predicting subsequent atopic manifestations up to age 20 yr. A cohort of 200 unselected, full‐term newborns were prospectively followed up from birth to age 20 yr. The CS‐IgE level was successfully measured in 190 subjects at birth. The subjects were re‐examined at ages of 5, 11 and 20 yr with assessment of the occurrence of allergic symptoms during the preceding year, skin prick testing and measurement of serum total IgE. An elevated CS‐IgE level was associated with allergic symptoms and skin prick test positivity at age 5 yr (p = 0.03 and 0.01), with allergic rhinoconjunctivitis at age 20 yr (p = 0.04) and with an elevated serum total IgE at ages of 11 and 20 yr (p = 0.02 and 0.01). The sensitivity of CS‐IgE, i.e. the probability of an elevated CS‐IgE in an infant who subsequently develops atopy, in predicting skin prick test‐verified atopy at ages of 5 and 20 yr was 50% and 26%, respectively. The combination of elevated CS‐IgE and positive family history of allergy was strongly associated with subsequent atopic manifestations. Nevertheless, it showed a reduced sensitivity as compared to CS‐IgE or family history of allergy. We conclude that an elevated CS‐IgE level predicts subsequent atopy up to age 20 yr.

Background Studies suggest that patch testing with formaldehyde releasers (FRs) gives significant additional information to formaldehyde 1% aq. and should be considered for addition to the European baseline series (EBS). It is not known if this is also true for formaldehyde 2% aq. Objectives To determine the frequency of sensitization to formaldehyde 2% aq. and co‐reactivity with FRs. To establish whether there is justification for including FRs in the EBS. Materials and Methods A 4‐year, multi‐center retrospective analysis of patients with positive patch test reactions to formaldehyde 2% aq. and five FRs. Results A maximum of 15 067 patients were tested to formaldehyde 2% aq. and at least one FR. The percentage of isolated reactions to FR, without co‐reactivity to, formaldehyde 2% aq. for each FR were: 46.8% for quarternium‐15 1% pet.; 67.4% imidazolidinyl urea 2% pet.; 64% diazolidinyl urea 2% pet.; 83.3% 1,3‐dimethylol‐5, 5‐dimethyl hydantoin (DMDM) hydantoin 2% pet. and 96.3% 2‐bromo‐2‐nitropropane‐1,3‐diol 0.5% pet. This demonstrates that co‐reactivity varies between FRs and formaldehyde, from being virtually non‐existent in 2‐bromo‐2‐nitropropane‐1,3‐diol 0.5% pet. (Cohen's kappa: 0, 95% confidence interval [CI] −0.02 to 0.02)], to only weak concordance for quaternium‐15 [Cohen's kappa: 0.22, 95%CI 0.16 to 0.28)], where Cohen's kappa value of 1 would indicate full concordance. Conclusions Formaldehyde 2% aq. is an inadequate screen for contact allergy to the formaldehyde releasers, which should be considered for inclusion in any series dependant on the frequency of reactions to and relevance of each individual allergen.

Contact dermatitis tremendously impacts the quality of life of suffering patients. Currently, diagnostic regimes rely on allergy testing, exposure specification, and follow-up visits; however, distinguishing the clinical phenotype of irritant and allergic contact dermatitis remains challenging. Employing integrative transcriptomic analysis and machine-learning approaches, we aimed to decipher disease-related signature genes to find suitable sets of biomarkers. A total of 89 positive patch-test reaction biopsies against four contact allergens and two irritants were analyzed via microarray. Coexpression network analysis and Random Forest classification were used to discover potential biomarkers and selected biomarker models were validated in an independent patient group. Differential gene-expression analysis identified major gene-expression changes depending on the stimulus. Random Forest classification identified CD47, BATF, FASLG, RGS16, SYNPO, SELE, PTPN7, WARS, PRC1, EXO1, RRM2, PBK, RAD54L, KIFC1, SPC25, PKMYT, HISTH1A, TPX2, DLGAP5, TPX2, CH25H, and IL37 as potential biomarkers to distinguish allergic and irritant contact dermatitis in human skin. Validation experiments and prediction performances on external testing datasets demonstrated potential applicability of the identified biomarker models in the clinic. Capitalizing on this knowledge, novel diagnostic tools can be developed to guide clinical diagnosis of contact allergies.