Is benzyl alcohol a significant contact sensitizer?

BACKGROUND: Benzyl alcohol is a widely used preservative, solvent and fragrance material. According to published data, it is a rare sensitizer in humans. OBJECTIVES: To identify characteristics and sensitization patterns of patients with positive patch test reactions to benzyl alcohol and to check the reliability of the patch test preparation benzyl alcohol 1% pet. PATIENTS AND METHODS: Retrospective analysis of data from the Information Network of Departments of Dermatology (IVDK), 2010-2019. RESULTS: Of 70 867 patients patch tested with benzyl alcohol 1% pet., 146 (0.21%) showed a positive reaction, most of them (89%) only weakly positive. The number of doubtful and irritant reactions significantly exceeded the number of positive reactions. Reproducibility of positive test reactions was low. Among benzyl alcohol-positive patients, compared to benzyl alcohol-negative patients, there were significantly more patients with leg dermatitis (17.8% vs. 8.6%), more patients aged 40 years or more (81.5% vs. 70.5%) and more patients who were tested because of a suspected intolerance reaction to topical medications (34.9% vs. 16.6%). Concomitant positive reactions were mainly seen to fragrances, preservatives and ointment bases. CONCLUSIONS: Sensitization to benzyl alcohol occurs very rarely, mainly in patients with stasis dermatitis. In view of our results, benzyl alcohol cannot be regarded as a significant contact allergen, and therefore marking it as skin sensitizer 1B and labelling it with H 317 is not helpful.

Trends and current spectrum of contact allergy in Central Europe: results of the Information Network of Departments of Dermatology (IVDK) 2007-2018.

BACKGROUND: Changing patterns of exposure lead to changes in the spectrum of contact allergy in the general population and in patients patch tested for suspected contact allergy. The main contact allergens (haptens) are assembled in the so-called 'baseline series'. OBJECTIVES: To present the current spectrum of contact allergy to baseline series allergens, and its temporal development over the last 12 years, based on data collected by the 56 active departments of the trinational Information Network of Departments of Dermatology (IVDK). METHODS: Patch-test data, along with core demographic and clinical information, subdivided into 4-year periods for all patients patch tested with the baseline series in the IVDK, were analysed descriptively. Moreover, log-binomial regression analysis addressed temporal trends of specific contact allergies, adjusted for potentially confounding factors. RESULTS: Among the 125 436 patients tested with the German baseline series, the most common allergens were nickel (14·7%), fragrance mix I (8·1%), Myroxylon pereirae resin (7·5%) and cobalt (5·2%), with no conclusive trend. The rise and fall of contact allergy to methylchloroisothiazolinone/methylisothiazolinone (MI), following (self-) regulation in the European Union, reflected the MI contact allergy epidemic. Propolis showed a marked upward trend with a prevalence of 3·94% during the period 2015-2018. CONCLUSIONS: Decreases in sensitization prevalence likely reflect reduced exposure, with some lag, as seen with hydroxyisohexyl 3-cyclohexene carboxaldehyde. If no (sufficient) decrease can be observed despite interventions, such as for nickel and chromium, affected subgroups should be identified and their causative exposures explored. Finally, increases such as that observed with propolis, certainly warrant targeted investigation of the exposures driving sensitization, and possibly intervention. What is already known about this topic? Contact allergy is prevalent in the general population. Surveillance based on clinical data offers timely information on trends concerning certain allergens or subgroups at risk. What does this study add? This analysis provides an update of the current contact allergy prevalence in Central Europe, including time trends. This study describes the demographic and clinical profile of patients tested from 2007 to 2018. This research identifies contact allergens that require (further) preventive efforts. Linked Comment: Schuttelaar. Br J Dermatol 2020; 183:800-801.

Challenging a paradigm: skin sensitivity to sodium lauryl sulfate is independent of atopic diathesis.

BACKGROUND: Sodium lauryl sulfate (SLS) is the best-studied detergent in irritant contact dermatitis. In atopic dermatitis, the two major pathophysiological abnormalities concern skin barrier function and regulation of cutaneous immune responses. The probability of atopic skin diathesis can be assessed by comprehensive analysis of patient history, as well as clinical and laboratory findings, resulting in the Erlangen Atopy Score (EAS). OBJECTIVES: To investigate the impacts of (i) atopic skin diathesis according to the EAS and (ii) the physician-assessed diagnoses 'atopic dermatitis', 'allergic rhinitis' and 'allergic asthma' on SLS skin reactions. METHODS: This is a retrospective analysis of data from 2030 consecutive patients patch tested with SLS (0·25% aqueous) from two tertiary referral centres in Germany, from 2008 to 2014. RESULTS: Patients with a high probability of atopic skin diathesis showed no significant increase in positive SLS reactions compared with patients without atopic skin diathesis (14·2% vs. 16·8%). The grading of positive SLS skin reactions (1-4) revealed no differences in patients with or without atopic skin diathesis. Furthermore, diagnoses of atopic dermatitis, allergic rhinitis or allergic asthma had no impact on positive SLS skin reactions in multivariate logistic regression analysis. CONCLUSIONS: We found no association of increased skin irritability to SLS with atopic skin diathesis, atopic dermatitis, allergic rhinitis or allergic asthma in a large patient cohort. It therefore seems that the test of skin irritability with SLS, which is currently common practice in many centres, does not allow prediction of susceptibility to irritant eczematous inflammation in atopic vs. nonatopic individuals. What's already known about this topic? Irritant contact dermatitis and atopic skin diathesis share impaired skin barrier function as a pathophysiological pattern. Sodium lauryl sulfate (SLS) is tested at 0·25% aqueous as an irritant control in patch testing, and hence the results might be affected by atopic skin diathesis. What does this study add? Challenging a long-standing paradigm, we found no association of increased reactivity to SLS patch tests in individuals with atopic skin diathesis, atopic dermatitis, allergic rhinitis or allergic asthma in a large patient cohort. Thus, irritant control testing with SLS, which is useful in interpreting doubtful allergen patch test results, does not depend on individual atopy status.

Assessment of occupational exposure and spectrum of contact sensitization in metalworkers with occupational dermatitis: results of a cohort study within the OCCUDERM project.

BACKGROUND: Metalworkers occupationally exposed to metals, tools, metalworking fluids (MWFs), technical oils, gloves, skin care products etc. frequently suffer from occupational dermatitis (OD). OBJECTIVES: To investigate occupational exposure and to identify relevant occupational sensitizers in metalworkers with OD, and to evaluate suitability of current German patch test recommendations for this occupational group. PATIENTS AND METHODS: As part of the OCCUDERM project, occupational exposure of 230 metalworkers with suspected OD patch tested in the departments of dermatology in Göttingen and Osnabrück (both Lower Saxony, Germany) in 2012-2017 was recorded by questionnaire. These data, as well as results, of patch testing with standardized allergens and with workplace material were analysed. RESULTS: Metalworking fluids and skin care products were the most important exposures. Among MWF allergens, most frequently sensitizations to formaldehyde and formaldehyde releasers, colophony/abietic acid and monoethanolamine were observed. Sensitization to methylisothiazolinone (MI) was frequent, probably as part of the general European epidemic of contact allergy to MI in leave-on cosmetics. Sensitization to glove ingredients only played a minor role. CONCLUSIONS: The known occupational allergen spectrum could largely be confirmed. In order not to miss relevant sensitizations, patch testing with material from the patients' workplaces in parallel to baseline and MWF series is recommended. Sensitizations diagnosed could not always be linked to particular occupational exposures.

Atopy patch testing with aeroallergens in a large clinical population of dermatitis patients in Germany and Switzerland, 2000-2015: a retrospective multicentre study.

BACKGROUND: The diagnostic significance of the atopy patch test for the management of dermatitis possibly triggered by aeroallergens is still controversial. However, sufficiently large studies with routinely tested standardized aeroallergen patch test preparations in dermatitis patients are lacking. OBJECTIVE: To evaluate the reaction frequency and the reaction profiles of 10 until mid-2015 commercially available, standardized aeroallergen patch test preparations of the 'Stallerpatch' test series (Stallergenes, Antony Cedex, France) in a large multicentre patient cohort. METHODS: A retrospective data analysis of patients with suspected aeroallergen-dependent eczematous skin lesions was performed, who were patch tested in 15 Information Network of Departments of Dermatology-associated clinics between 2000 and 2015. Patients were stratified according to their atopic dermatitis (AD) status. RESULTS: The study group included 3676 patients (median age 41 years, 34.8% males, 54.5% AD). The most common aeroallergens causing positive patch test reactions were Dermatophagoides pteronyssinus (19.6%), Dermatophagoides farinae (16.9%), birch (6.2%), timothy grass (6.0%), cat dander (5.4%), mugwort (4.9%) and dog dander (4.6%). Reactions to other pollen allergen preparations, that is 5 grasses (3.2%), cocksfoot (2.1%) and plantain (1.6%), were less common. Positive patch test reactions to aeroallergens were consistently more frequent in patients with AD. These patients showed proportionally less dubious, follicular, irritant and weak positive reactions. Independent of AD status, a patient history of past or present allergic rhinitis was associated with an increased chance of a positive aeroallergen patch test reaction to pollen allergens. CONCLUSION: The aeroallergen patch test is a useful add-on tool in clinical routine, especially in patients with AD and/or respiratory allergy. A patch test series comprising Dermatophagoides pteronyssinus, Dermatophagoides farinae, birch, timothy grass, cat dander and mugwort seems to be suitable. Controlled studies with specific provocation and elimination procedures are required to further evaluate the diagnostic significance of the proposed screening series.

[How common is fragrance allergy really?] / Wie häufig ist die Duftstoffallergie wirklich?

BACKGROUND: Fragrances are regarded as the most common contact allergens after nickel. In this context, the frequency of positive patch test reactions to fragrance mix is often presented as proof. According to EU regulation No. 1223/2009, 26 fragrances that are regarded as significant allergens have to be declared on cosmetic products. OBJECTIVES: The frequency of patch test reactions to fragrances and differentiation between frequently and rarely sensitizing fragrances were evaluated. MATERIALS AND METHODS: Data from the Information Network of Departments of Dermatology (IVDK), mostly of the years 2016-2018, were retrospectively analyzed. RESULTS: Frequency of positive reactions to fragrance mix I in the departments of dermatology joining the IVDK reached a historical low of 5.4% in 2018. Since 2013, positive reactions to fragrance mix II have been declining, yielding 3.2% in 2018. Of fragrance mix I, the allergen with the most positive test reactions is no longer oakmoss absolute, but isoeugenol. In fragrance mix II, hydroxyisohexyl 3­cyclohexene carboxaldehyde (HICC) is still leading. Only 11 of the 26 fragrances subject to mandatory declaration elicited allergic test reactions in more than 1% of the patients tested. DISCUSSION: The decline of positive test reactions to the fragrance mixes is mainly due to the reduced use of oakmoss containing atranol and chloroatranol, and HICC. Use of these substances in cosmetic products was prohibited within the EU starting in August 2019. Therefore, a further decline of the sensitization frequencies can be expected. A differentiated consideration of the individual fragrances under allergological aspects is urgently required.

[Preservative allergy : An enduring issue]. / Dauerbrenner Konservierungsmittelallergie : Was geht, was kommt, was bleibt?

BACKGROUND: Preservatives in cosmetics are often suspected as contact sensitizers and hence frequently patch tested in dermatitis patients. Exposure in this field has changed over the course of years. OBJECTIVE: To describe the frequency of contact sensitization to various preservatives. MATERIALS AND METHODS: Retrospective data analysis from the Information Network of Departments of Dermatology (IVDK) for the years 2009-2018. RESULTS: Frequency of sensitization to methylisothiazolinone (MI) has increased from 2.0% in 2009 to 7.2% in 2013. Since 2014, the rate has been falling again. Increasing the patch test concentration of methyldibromo glutaronitrile (MDBGN) in 2016 has caused a sudden rise in positive patch test reactions from 2.0% to more than 4.5%. Allergic reactions to other preservatives occurred in less than 1% of the patients tested. DISCUSSION: Since 2014, the worldwide "epidemic" of sensitization to MI has been subsiding in Central Europe, thanks to corresponding restrictions on use. Since 2008, there is no longer any widespread exposure to MDBGN; the new, higher test concentration elicits many false-positive test reactions and explains the sudden rise in positive patch test reactions since 2016. Despite widespread use, phenoxyethanol, benzoates, benzyl alcohol, parabens and sorbates rarely cause allergic reactions. Therefore, they can be recommended for cosmetics from the epidemiological-allergological point of view.

The frequency of specific contact allergies is reduced in patients with psoriasis.

BACKGROUND: Earlier studies suggested an inverse association between contact allergy and psoriasis, although the results of clinical studies have been inconsistent. Gene expression studies in human contact allergy focusing on immune responses revealed nickel being an inducer of T helper (Th)1/Th17 and some Th22 immune polarization, whereas fragrances were found to promote a Th2-dominated immune activation. OBJECTIVES: To investigate the epidemiological association between contact allergy and psoriasis in a large multicentre cohort and to analyse the sensitization profile to specific allergens in these patients. METHODS: Retrospective analysis of patch-tested patients from 56 departments of dermatology (1996-2015), including 2387 patients with psoriasis and 161 989 control patients. All patients with atopic dermatitis were excluded from both groups. RESULTS: The odds ratio (OR) for contact allergy was calculated to be 0·55 in patients with psoriasis (95% confidence interval 0·50-0·59). Logistic regression analyses with several independent variables indicated a 'protective effect' of having psoriasis for most allergens, independently of age, sex, affected body site and patch test indication. Fragrance mix II (OR 0·36) and lanolin alcohols (OR 0·38) were found to be among the least common allergens in patients with psoriasis. In contrast, the frequency of contact dermatitis to nickel was only marginally affected in patients with psoriasis compared with controls (OR 0·75). CONCLUSIONS: The inverse association between psoriasis and allergic contact sensitization is likely to be not exclusively mediated by psoriasis itself. The polarization of the activated immune response by specific allergens may influence the occurrence and significance of contact allergies in underlying immune-mediated diseases, eventually even beyond the skin.

[Type IV contact allergies in the food processing industry: an update]. / Typ-IV-Kontaktallergien in Nahrungsmittelberufen: Eine aktuelle Übersicht.

BACKGROUND: The food sector is one of the high-risk areas for occupational irritative and allergic contact eczema. OBJECTIVES: The present work provides an overview of the main allergens as well as sensitization frequencies and risk in various food industry occupations. METHODS: The literature on type IV sensitization in the food sector is summarized. RESULTS: The relative risk of developing a work-related eczema in food processing is increased by more than 3 times. The comparison group was calculated on the basis of the proportion of documented cases in the IVDK (Informationsverbund Dermatologischer Kliniken) network per 100,000 working persons in relation to the average of the years 2005 and 2010. For this purpose, the average risk of all patients was set as reference to 1. Bakers, pastry chefs, cooks and meat and fish processors are mainly affected. In addition to irritant contact eczema, allergic contact eczema and protein contact dermatitis often occur. Leading haptens (main allergens) are rubber ingredients, but also disinfectants and compositae. CONCLUSION: Only a few contact allergens are responsible for the majority of job-relevant sensitizations in the food industry.

Occupational contact sensitization in female geriatric nurses: Data of the Information Network of Departments of Dermatology (IVDK) 2005-2014.

BACKGROUND: Geriatric nurses (GN) have a high risk of occupational contact dermatitis (OCD), with chronic irritant contact dermatitis predominating. However, allergic contact dermatitis is an important issue as well. Little is known whether the relevant occupational allergen spectrum reported in the 1990s, including fragrances, preservatives, rubber chemicals and ingredients of surface disinfectants to be the most common sensitizers in GN, is still valid. OBJECTIVES: To monitor the current allergen spectrum in GN with OCD and verify the validity of the patch test recommendations (baseline-, preservative-, ointment base-, rubber-, disinfectant, series and fragrances) in GN with suspected OCD given by the German Contact Dermatitis Research Group (DKG). METHODS: Retrospective analysis of IVDK data (2005-2014) of 743 female GN with OCD, in comparison to 695 GN without OCD. RESULTS: GN with OCD reacted significantly more frequently to both fragrance mixes, hydroxyisohexyl 3-cyclohexene carboxaldehyde (HICC), thiuram mix, zinc diethyldithiocarbamate and mercaptobenzothiazole than GN without OCD. Reactions to MDBGN, methylchloroisothiazolinone/methylisothiazolinone and oil of turpentine occurred substantially, but not significantly more frequently among GN with OCD. The latter may be due to former use of a special alcoholic liniment in geriatric care. Among material from the patients' workplaces, tetrazepam was a frequent allergen, due to dust exposure from pill crushing. Furthermore, occupationally used protective gloves, body care products as well as surface disinfectants were often tested positively. CONCLUSIONS: The general allergen spectrum in GN with OCD is unchanged, so the DKG patch test recommendations are still valid. Prevention of occupational sensitization should focus on fragrance-free hygiene and body care products, usage of accelerator-free protective gloves and avoidance of drug dust exposure.

Contact sensitization in patients with suspected cosmetic intolerance: results of the IVDK 2006-2011.

BACKGROUND: Ingredients of leave-on cosmetics and body care products may sensitize. However, not every case of cosmetic intolerance is due to contact sensitization. OBJECTIVE: To describe the frequency of contact sensitization due to cosmetics in a large clinic population, and a possible particular allergen pattern. METHODS: Retrospective analysis of data from the Information Network of Departments of Dermatology, 2006-2011. RESULTS: Of 69 487 patients tested, 'cosmetics, creams, sunscreens' was the only suspected allergen source category in 10 124 patients (14.6%). A final diagnosis 'allergic contact dermatitis' was stated in 2658 of these patients (26.3%).Compared to a control group, there were significantly more reactions to fragrance mixes I and II, balsam of Peru, methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) and lanolin alcohols. No special pattern of fragrance sensitization could be identified. Among the preservatives, MI was by far the leading allergen, while sensitization to other widely used compounds like parabens or phenoxyethanol was rare. CONCLUSIONS: True allergic reactions to cosmetic ingredients are rarer than generally assumed. Limitation of exposure to MI in leave-on cosmetics and body care products is urgently needed.

[Diagnostic workup of fragrance allergy]. / Diagnostik der Duftstoffallergie.

The diagnostic workup of contact allergy to fragrances must not be limited to patch testing with the two well-established fragrance mixes. False-positive reactions to these mixes occur in up to 50 % of the patch tested patients. For the diagnostic work-up of positive reactions, and in cases of suspected fragrance allergy, patch testing with the single mix components and additional fragrances is mandatory. Frequently sensitizing fragrance materials are the 14 components of the two fragrance mixes and tree moss (Evernia furfuracea), ylang ylang oil (I + II; Cananga odorata), lemongrass oil (Cymbopogon schoenanthus), sandalwood oil (Santalum album), jasmine absolute (Jasminum spp.), and, less frequently, clove oil (Eugenia caryophyllus), cedarwood oil (Cedrus atlantica/deodara, Juniperus virginiana), Neroli oil (Citrus aurantium amara flower oil), salicylaldehyde, narcissus absolute (Narcissus spp.), and patchouli oil (Pogostemon cablin).

[Contact allergies in the German workforce : Data of the IVDK network from 2003-2013]. / Kontaktallergien bei Erwerbstätigen in Deutschland : Ergebnisse des IVDK-Netzwerkes 2003-2013.

BACKGROUND: In Germany, occupational skin diseases rank first in the occupational skin disease statistics for many years. Especially, occupationally acquired contact allergies as well as multi-sensitization are the most important predictors for a poor prognosis and persistent eczema. OBJECTIVES: To update the spectrum and sensitization frequencies of most frequent allergens from the standard series in Germany in patients with occupationally acquired type IV sensitizations in general and within different occupational groups. METHODS: Data of all employed patients (age range: 16-68 years, n = 14234) patch tested between 2003 and 2013 in the German Departments of the Information Network of Departments of Dermatology (IVDK) and diagnosed occupationally acquired contact dermatitis after patch testing were analyzed. The control group was composed of all other patients (n = 31706) within the same time frame, in which occupationally acquired allergic contact dermatitis was negated explicitly. RESULTS: The prevalence Ratio (PR; indicating risk) was significantly increased for: Thiuram-mix (PR 5.63 95 %CI 4.97-6.4), zinkdiethyldithiocarbamate (PR 6.22 95 %CI 4.76-8.22), mercaptobenzothiazole (MBT) (PR 3.88 95 %CI 3.09-4.89), mercapto-mix without MBT (PR 3.23 95 %CI 2.59-4.03), N-isopropyl-N'-phenyl-p-phenylene diamine (IPPD) (PR 2.3195 %CI 1.87-2.86), epoxy resin (PR 2.82 95 %CI 2.45-3.25), chloromethylisothiazolinone/methylisothiazolinone (MCI/MI) (PR 2.19 95 %CI 1.97-2.42) and compositae mix II (PR 2.05 95 %CI 1.45-2.89). They were the predominant occupational allergens and were at least associated with a doubled risk (PR ≥ 2.0) for acquiring occupationally allergic contact dermatitis. The highest risk increase was identified in employees in the health services, in agriculture, metal industry, food and service industry as well as building trades CONCLUSIONS: A limited number of occupationally relevant allergens cause the majority of sensitizations in the workforce, if standard series allergens are concerned. Data analysis of national and international contact allergy data bases provide valuable information on sensitization rates and profiles in skin risk occupations to implement targeted prevention strategies. To diagnose occupational allergic contact dermatitis in individual cases additional testing of occupation related patch test series as well as patients' own products is commonly inevitable.

[Not Available]. / Kontaktallergien im Kindesalter.

Allergic contact eczema in children is frequent. If clinically suspected, a patch test should be performed. In the present study, data obtained from 116,742 patients who had undergone a patch test from 2005-2014 were analysed. The children group (range 0-12 years) included 925 patients. If at least 700 tested individuals were considered, the most frequent sensitizations in this group were nickel sulfate (8.5 %), fragrance mix I (5.5 %), and colophony (3.4 %), whereby sensitisation in adults was higher for nickel sulfate (15.5 %) and fragrance mix 1 (8.4 %), while being similar for colophony (3.7 %). In adolescents with and without a profession, nickel sulfate (11.1 and 13.6 %, respectively) and cobalt (II) chloride (3.9 and 3.4 %, respectively) were the most frequent positively tested contact allergens. Sensitisations toward fragrance mix I was low (3.9 and 3.4 %, respectively) in comparison to the adult group (8.4 %). In both children and adolescents, toluene diamine and paraphenylenediamine sensitizations were not infrequent, but it must be considered that these allergens were only tested if suspected. The data show that the sensitisation profile among children and adolescents display patterns similar to those in adults. Sensitisations in childhood and adolescence towards dyes like paraphenylendiamine may be associated with increased use of tattooing in these groups.

[Should metal alloy discs be used for patch testing in suspected metal implant intolerance reaction?]. / DKG-Stellungnahme zur Epikutantestung von Metalllegierungsplättchen bei Verdacht auf Metallimplantat-Unverträglichkeit.

Intolerance reactions to metal implants may be caused by metal allergy. However, prior to implantation, patch testing should not be done in a prophylactic-prophetic approach. Pre-implant patch testing should only be performed to verify or exclude metal allergy in patients with a reported respective history. In the case of implant-in particular arthroplasty-related complications like, for example, pain, effusion, skin changes, reduced range of motion, or loosening, orthopedic-surgical differential diagnostics should be performed first. Allergological workup of suspected metal implant allergy should be done with the DKG baseline series which contains nickel-, cobalt- and chromium-preparations. Various studies assessing the usefulness of metal alloy discs for patch testing proved that this approach does not give reliable information about metal allergy. Positive patch test reactions to the discs cannot be assigned to a specific metal within the disc alloy components. Furthermore, availability of such metal discs might be an invitation to uncritical testing. Accordingly, due to lack of benefit in comparison to patch testing with standardized metal salt preparations, we do not recommend patch testing with metal alloy discs.

Skin irritability to sodium lauryl sulfate is associated with increased positive patch test reactions.

BACKGROUND: As previous observations have indicated an inter-relationship between irritant and allergic skin reactions we analysed data of synchronous allergen and sodium lauryl sulfate (SLS) patch tests in terms of a relationship between SLS responsiveness and allergic patch test reactions. OBJECTIVES: To analyse differences in terms of allergen-specific and overall reaction profiles between patients with vs. those without an irritant reaction to SLS. METHODS: Clinical data of 26 879 patients patch tested from 2008 to 2011 by members of the Information Network of Departments of Dermatology were analysed. After descriptive analyses, including the MOAHLFA index, the positivity ratio and the reaction index, a negative binomial hurdle model was adopted to investigate the correlation between SLS reactivity and positive patch test reactions. RESULTS: Men, patients aged ≥ 40 years and patients with an occupational dermatitis background were over-represented in the SLS-reactive group. Patients with an irritant reaction to SLS showed a higher proportion of weak positive reactions, as well as more questionable and irritant reactions to contact allergens than patients not reactive to SLS. The risk of an additional positive patch test reaction increased by 22% for SLS-reactive patients compared with those who were SLS negative. CONCLUSIONS: The marked association between SLS reactivity and the number of positive reactions in patch test patients may be due to nonspecific increased skin reactivity at the moment of patch testing only. However, increased SLS reactivity could also be due to longer-lasting enhanced skin irritability, which may have promoted (poly-)sensitization. Further studies, for example with longitudinal data on patients repeatedly patch tested with SLS and contact allergens, are necessary.

Surveillance of contact allergies: methods and results of the Information Network of Departments of Dermatology (IVDK).

Contact allergy (CA) surveillance networks provide information to a multitude of stakeholders, which is indispensable for evidence-based decision-making in the field of prevention. Methods and results of the German surveillance system on CA are reviewed and discussed with reference to other systems. The German network structure comprises 56 departments of dermatology and includes all patients who are patch-tested for suspected CA. Data analysis considers the results of patch testing and further pertinent information for each patient. Following aspects are addressed: (i) the description of the clinical population, (ii) evaluation of patch test reactions, (iii) relationship between patch test results and population characteristics. Trend analyses on chromate (decreasing), epoxy resin (increasing) and nickel (heterogeneous) served as examples for surveillance system analyses, with the identification of sentinel events, as well as proof of success or failure of prevention. In addition, external data sources can be used such as sales data of patch test preparations to estimate frequencies of sensitization on a population level. National prescription data of drugs and statistics of labelling of preservatives on cosmetics can be included, the latter two approaches allowing for risk estimates conferred by specific allergens.