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)

Comparison of patch testing Brazilian (Green) propolis and Chinese (poplar-type) propolis: Clinical epidemiological study using data from the Information Network of Departments of Dermatology (IVDK)

BACKGROUND

Propolis types differ regarding their chemical composition.

OBJECTIVES

To compare patch test results based on Brazilian (Green) propolis with data based on Chinese (poplar-type) propolis, and to evaluate the specifications of raw materials used for the PT preparations.

METHODS

In the Information Network of Departments of Dermatology (IVDK), 1290 consecutive patients were patch tested with Brazilian (Green) propolis (NH400, SmartPractice Europe). Patch test reactivity was compared with results obtained with Chinese (poplar-type) propolis (NA71, SmartPractice Europe) by calculating frequencies and corresponding 95% confidence intervals. Data on the specifications of raw materials used for NH400 and NA71 were obtained from the manufacturer.

RESULTS

Positive reactions to NH400 were found in 303 (23.5%) patients with unclear clinical relevance in most cases. Patients reacting to NH400 were less often sensitised to fragrances and colophony, but more often to nickel sulphate and cobalt chloride than patients reacting to NA71. The NH400 batch used contained high levels of aerobic bacteria, and was not purified by ethanolic extraction.

CONCLUSIONS

Pattern of concomitant reactivity along with raw material properties suggests that the high frequency of positive reactions to NH400 may primarily result from bacterial contamination or impurities in the PT preparation rather than from propolis constituents.

Is the Use of the Extended (Meth)acrylate Series - Nails Justified? Characterization of Nail Acrylate Allergy in a Tertiary Medical Centre

Methacrylate allergy is a common cause of allergic contact dermatitis, and its incidence has surged over the past decade. Consequently, the primary sensitizing agent, 2-hydroxyethyl methacrylate, was recently added to the European Baseline Series of contact allergens. This study aimed to assess the added value of testing for allergens included in the (Meth)Acrylate Series - Nails, in addition to 2-hydroxyethyl methacrylate, as well as to characterize patients who may benefit from more extensive testing. A retrospective analysis of medical records of patch-tested patients was conducted between June 2013 and July 2022. Among the 3,828 patients who underwent patch testing, 396 were tested with the (Meth)Acrylate Series - Nails; 153 (38.6%) of those patients tested positive for at least 1 acrylate. The most common hapten was 2-hydroxyethyl methacrylate (85.6%), followed by hydroxypropyl methacrylate (85.0%) and ethylene glycol dimethacrylate (80.4%). In our study, 22/153 patients (14.4%) would have been missed if tested only for 2-hydroxyethyl methacrylate. The analysis showed that including hydroxypropyl methacrylate and ethylene glycol dimethacrylate improved detection rate to 98%, rendering the use of the entire tray unnecessary in most cases.

Quality of patch testing patient's own material in patients with suspected occupational skin diseases throughout Germany: Interim results of the German Social Accident Insurance (DGUV) research project FB 317b

BACKGROUND

Due to limited availability of commercial test preparations, patch testing patient's own material (POM) is of great importance to diagnose occupational allergic contact dermatitis.

OBJECTIVES

To assess the quality of performance and documentation of patch testing with POM in patients with suspected occupational skin diseases (OSD) in Germany.

METHODS

Retrospective-prospective analysis of protocols of patch tests with POM was conducted between 2013 and 2021 in patients with suspected OSD and submitted to statutory accident insurance institutions. Assessments were done by predefined criteria.

RESULTS

Three thousand and four patch tests with POM from 460 patients were included. A full description of the POM was provided in 73.3% of all tests. The test concentration, test vehicle and pH value were documented in 74.3%, 70.5% and 42.2% of tests, for which the respective parameters were considered relevant. One hundred and sixty-one positive reactions to POM were documented. In 72%, sufficient patch testing with commercial test substances was conducted to investigate the positive reaction. In 30.4%, consecutive patch testing of all ingredients of the POM was done.

CONCLUSIONS

The results not only show considerable shortcomings mainly in documentation but also to some extent performance of patch tests with POM in patients with suspected OSD in Germany.

Analysis of Positive Patch Test Allergens in Allergic Contact Dermatitis Patients with Atopic Dermatitis

BACKGROUND

There has been debate regarding whether patients with atopic dermatitis (AD) have an altered frequency of contact allergen sensitization. Increased exposure to topical medications and moisturizers as well as impaired skin barrier function increase the risk of contact sensitization, whereas the Th2-skewed inflammatory pathway of AD is associated with a reduced risk.

OBJECTIVE

This retrospective study was performed to determine the characteristics of contact sensitization in allergic contact dermatitis (ACD) patients with a current or past history of AD.

METHODS

A clinical record review was conducted for patients referred to Ewha Womans University Medical Center, for patch tests between March 2017 and March 2021. We compared the rates of contact sensitization between ACD patients with and without AD.

RESULTS

In total, 515 patch test results were reviewed and divided into the AD group (n=53) and non-AD group (n=462). The AD group showed decreased any-allergen positivity (1+, 2+, or 3+) (56.6%) compared to the non-AD group (72.9%) (p=0.013). The positivity rate for budesonide was significantly higher in the AD group (p=0.011), while the prevalence of a positive result for balsam of Peru was higher in the non-AD group (p=0.036). Nickel sulfate, cobalt chloride, and potassium dichromate were the most common sensitized allergens in both groups.

CONCLUSION

Our study shows a decreased prevalence of contact sensitization in AD patients compared to non-AD patients. Clinicians should be aware of the risk of corticosteroid allergies in ACD patients with history of AD.

Allergenicity and Bioavailability of Nickel Nanoparticles Compared to Nickel Microparticles in Mice

Metal allergy is a common disease that afflicts many people. Nevertheless, the mechanism underlying metal allergy development has not been completely elucidated. Metal nanoparticles might be involved in the development of a metal allergy, but the associated details are unknown. In this study, we evaluated the pharmacokinetics and allergenicity of nickel nanoparticles (Ni-NPs) compared with those of nickel microparticles (Ni-MPs) and nickel ions. After characterizing each particle, the particles were suspended in phosphate-buffered saline and sonicated to prepare a dispersion. We assumed the presence of nickel ions for each particle dispersion and positive control and orally administered nickel chloride to BALB/c mice repeatedly for 28 days. Results showed that compared with those in the Ni-MP administration group (MP group), the Ni-NP administration group (NP group) showed intestinal epithelial tissue damage, elevated serum interleukin (IL)-17 and IL-1β levels, and higher nickel accumulation in the liver and kidney. Additionally, transmission electron microscopy confirmed the accumulation of Ni-NPs in the livers of both the NP and nickel ion administration groups. Furthermore, we intraperitoneally administered a mixed solution of each particle dispersion and lipopolysaccharide to mice and then intradermally administered nickel chloride solution to the auricle after 7 days. Swelling of the auricle was observed in both the NP and MP groups, and an allergic reaction to nickel was induced. Particularly in the NP group, significant lymphocytic infiltration into the auricular tissue was observed, and serum IL-6 and IL-17 levels were increased. The results of this study showed that in mice, Ni-NP accumulation in each tissue was increased after oral administration and toxicity was enhanced, as compared to those with Ni-MPs. Orally administered nickel ions transformed into nanoparticles with a crystalline structure and accumulated in tissues. Furthermore, Ni-NPs and Ni-MPs induced sensitization and nickel allergy reactions in the same manner as that with nickel ions, but Ni-NPs induced stronger sensitization. Additionally, the involvement of Th17 cells was suspected in Ni-NP-induced toxicity and allergic reactions. In conclusion, oral exposure to Ni-NPs results in more serious biotoxicity and accumulation in tissues than Ni-MPs, suggesting that the probability of developing an allergy might increase.

Patch test results with the European baseline series, 2019/20-Joint European results of the ESSCA and the EBS working groups of the ESCD, and the GEIDAC

BACKGROUND

Continual analyses of patch test results with the European baseline series (EBS) serve both contact allergy surveillance and auditing the value of included allergens.

OBJECTIVES

To present results of current EBS patch testing, obtained in 53 departments in 13 European countries during 2019 and 2020.

METHODS

Anonymised or pseudonymised individual data and partly aggregated data on demographic/clinical characteristics and patch test rest results with the EBS were prospectively collected and centrally pooled and analysed.

RESULTS

In 2019 and 2020, 22 581 patients were patch tested with the EBS. Sensitization to nickel remained most common (19.8 [19.2-20.4]% positivity [95% confidence interval]). Fragrance mix I and Myroxylon pereirae yielded very similar results with 6.80 (6.43-7.19)% and 6.62 (6.25-7.00)% positivity, respectively. Formaldehyde at 2% aq. yielded almost one percentage point more positive reactions than 1% concentration (2.49 [2.16-2.85]% vs. 1.59 [1.33-1.88]); methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) and MI alone up to around 5% positives. Among the new additions, propolis was most commonly positive (3.48 [3.16-3.82]%), followed by 2-hydroxyethyl methacrylate (2.32 [2.0-2.68]%).

CONCLUSION

Ongoing surveillance on the prevalence of contact sensitization contributes to an up-to-date baseline series containing the most frequent and/or relevant contact sensitizers for routine patch testing in Europe.

Prevalence of contact allergy to corticosteroids in a Danish patient population

Background

Allergic contact dermatitis to corticosteroids can be a challenging diagnosis as corticosteroids are used in the treatment of dermatitis. The prevalence of contact allergy to corticosteroid varies between previous studies.

Objective

To study the prevalence of sensitization to budesonide, tixocortol‐21‐pivalate and hydrocortisone‐17‐butyrate in a Danish patient population from 2006‐2020, cross‐sensitization, risk factors and clinical relevance.

Methods

A retrospective analysis of patch test data and MOAHLFA index was performed among 6823 patients consecutively patch tested with TRUE test as part of the baseline series.

Results

A positive patch test for corticosteroids was found in 185 patients (1.2% budesonide, 1.6% tixocortol‐21‐pivalate, 1.0% hydrocortisone‐17‐butyrate) without gender difference. For women, the prevalence of tixocortol‐21‐pivalate sensitization increased significantly from 1.3% in 2006–2008 to 2.9% in 2018–2020. Tixocortol‐21‐pivalate sensitization had more frequently clinical relevance in women (61.3%) compared to men (34.5%). Age above 40 years was positively associated to corticosteroid sensitization. Budesonide and hydrocortisone‐17‐butyrate accounted for 67.7% of co‐sensitizations.

Conclusions

The prevalence of corticosteroid sensitization was 2.7%. Age was the only risk factor for corticosteroid sensitization. The frequency of corticosteroid sensitization was stabile over time except for tixocortol‐21‐pivalate sensitization for women. About one third of sensitized patients had co‐sensitizations to other corticosteroid groups.

European patch test results with audit allergens as candidates for inclusion in the European Baseline Series, 2019/20 - Joint results of the ESSCAA and the EBSB working groups of the ESCD, and the GEIDACC

BACKGROUND

In 2019, a number of allergens (haptens), henceforth, 'the audit allergens,' were considered as potential additions to the European baseline series (EBS), namely, sodium metabisulfite, 2-bromo-2-nitropropane-1,3-diol, diazolidinyl urea, imidazolidinyl urea, Compositae mix II (2.5 or 5% pet), linalool hydroperoxides (lin-OOH), limonene hydroperoxides (lim-OOH), benzisothiazolinone (BIT), octylisothiazolinone (OIT), decyl glucoside, lauryl glucoside; Evernia furfuracea (tree moss), was additionally tested by some departments, too.

OBJECTIVES

To collect further data on patch test reactivity and clinical relevance of the audit allergens in consecutive patients across Europe.

METHODS

Patch test data covering the audit allergens in 2019 and 2020 were collected by those departments of the ESSCA testing these, as well as further collaborators from the EBS working group of the ESCD, and the Spanish GEIDAC. As patch test outcome, reactions between day (D) 3 and D5 were considered.

RESULTS

Altogether n=12403 patients were tested with any of the audit allergen. Positive reactions were most common to lin-OOH 1% pet. (8.74 (8.14-9.37)), followed by lin-OOH 0.5% pet., and lim-OOH 0.3% pet (5.41 (4.95-5.89)). Beyond these terpene hydroperoxides, BIT 0.1% pet. was the second most common allergen with 4.72 (4.2-5.28), followed by sodium metabisulfite 1% pet. (3.75 (3.32-4.23)) and Compositae mix 5% pet. (2.31 (1.84-2.87). For some allergens, clinical relevance was frequently difficult to ascertain.

CONCLUSIONS

Despite many positive patch test reactions, it remains controversial whether lin- and lim-OOH should be tested routinely, while at least the two preservatives BIT and sodium metabisulfite appear suitable. The present results are a basis for further discussion among the ESCD members and ultimately decision on their implementation into routine testing. This article is protected by copyright. All rights reserved.

Allergens in Hand, Foot, and Hand-Foot Eczema: An Intercomparison by Patch Testing

Background:

Hand eczema (HE), foot eczema (FE), and hand–foot eczema (HFE) manifest on exposure to various agents in day-to-day life or in occupations or both.

Objectives:

The objectives of this study were to identify pattern of allergens causing HE, FE, and HFE and to identify multiple and concurrent contact allergies.

Materials and Methods:

A study was conducted from October 2013 to August 2015 which included 190 patients. Patch test was performed for 78.94% of patients (n = 150). The statistical tests used were descriptive, Cramer's V, and Chi-square tests.

Results:

The most commonly affected group was HFE (55.8%) followed by HE (22.1%) and FE (22.1%). Allergens showed positivity either singly 56.3% (n = 67) or in combination 43.69% (n = 52). Nickel (41.79%) was the most common allergen in all the three groups followed by potassium dichromate. Late reactions (after day 7) were observed in 17.64% of patients (n = 21). Nickel was observed in 42.85% (n = 9) and paraphenylenediamine was observed in 28.57% of patients (n = 6) with P values of <0.001 and 0.050, respectively. Multiple contact allergies were seen in 44% of patients (n = 52). Concurrent reactions (55.8% [n = 29]), polysensitization (34.6% [n = 18]), and mixed reactions (9.6% [n = 5]) (P value of <0.001) were observed.

Conclusion:

Significant multiple contact allergies including concurrent reactions with nickel sulfate, potassium dichromate, cobalt chloride, and polysensitization were observed. No significant differences in allergen pattern were observed in HE, FE, and HFE.

Recommendation:

Day 7 reading is recommended in HFE.

Atopic skin diathesis rather than atopic dermatitis is associated with specific contact allergies

BACKGROUND

The association of atopic dermatitis (AD) and allergic contact dermatitis has been a matter of considerable uncertainty. Study results range from lack of any association to increased sensitization for multiple allergens, but fail to identify consistent allergen associations.

OBJECTIVE

We studied a large patch test cohort of patients stratified by their atopic skin diathesis using the Erlangen Atopy Score (EAS), independent of active skin disease.

METHODS

Retrospective multi-center data analysis from five departments of dermatology in Germany with 4,509 patients. Patients were grouped as "no atopic skin diathesis" (n = 2,165) and "atopic skin diathesis" (n = 1,743), according to EAS.

RESULTS

Significantly more individuals with atopic skin diathesis showed at least one positive patch test reaction to the baseline series compared to individuals without atopic skin diathesis (49.1 % vs. 38.3 %). In logistic regression analyses, atopic skin diathesis was associated with a significantly higher risk of sensitization to methylchloroisothiazolinone/methylisothiazolinone (OR 2.383) and methylisothiazolinone (OR 1.891), thiuram mix (OR 1.614), as well as nickel (OR 1.530), cobalt (OR 1.683), and chromium (OR 2.089).

CONCLUSIONS

Atopic skin diathesis proved to be the most important intrinsic risk factor for contact sensitization to few, specific allergens. Past or present AD was a less relevant variable.

Contact Allergy in Canada Versus United States: Analysis of the North American Contact Dermatitis Group Data 2005-2016

Differences in consumer product availability, distribution, and use may lead to national differences in contact sensitization frequencies.

OBJECTIVE

The aim of the study was to describe the differences in contact allergy between the United States (US) and Canada.

METHODS

This is a retrospective cross-sectional analysis of the North American Contact Dermatitis Group data from 2005 to 2016. Frequencies of demographics, clinical characteristics, positive reactions, trends, and occupations were calculated.

RESULTS

A total of 28,640 patients underwent patch testing. At least 1 positive patch test was observed in 18,599 patients (US, 11,641 [66.5%]; Canada, 6958 [62.5%]). When comparing the 2 groups, US positive reactions were more likely to occur in male patients (odds ratio [OR] = 1.40, 95% confidence interval [CI] = 1.31-1.49), older than 40 years (OR = 1.30, 95% CI = 1.22-1.38), Black (OR = 2.67, 95% CI = 2.24-3.19) or Hispanic race (OR = 3.53, 95% CI = 2.61-4.78), and/or patients with scattered generalized dermatitis (OR = 1.96, 95% CI = 1.80-2.13). They were less likely to occur in patients with eczema (OR = 0.61, 95% CI = 0.57-0.65) and Asian race (OR = 0.50, 95% CI = 0.44-0.56). Nickel (US, 16.0%; Canada, 22.4%) and methylisothiazolinone (US, 13.4%; Canada, 11.0%) were the top allergens. The third most frequent was neomycin (US, 11.7%) and fragrance mix I (Canada, 10.2%).

CONCLUSIONS

National differences in allergen prevalence and trends exist in North America.

Prevalence of contact allergies in the population compared to a tertiary referral patch test clinic in Jena/Germany

BACKGROUND

The contact allergy prevalences in patch-tested patients are usually higher than those in the population, owing to morbidity-driven selection.

OBJECTIVES

To examine the differences between two samples, one from the population, one from the patch test clinic, in one area of Germany (Jena, Thuringia).

METHODS

Between August 2008 and October 2011, a total of 519 participants of the population-based european dermato-epidemiology network (EDEN) fragrance study were patch tested in Jena using a TRUE Test baseline series extended with some pet.-based (fragrance) allergen preparations. Between 2007 and 2012 (inclusive), 1906 routine patients were patch tested for suspected allergic contact dermatitis (ACD) in the Jena University Hospital Department; of these 1694 (83.2%) with the German baseline series using pet./aq.-based, investigator-loaded allergens.

RESULTS

In the population (clinical) sample, 19.6% (41.1%) were sensitized to at least one of the allergens considered. The most common baseline series allergens in the population/clinical sample were nickel (10.5%/13.2%), fragrance mix (FM) II (2.9%/6.7%), FM I (2.3%/8.3%), and cobalt (1.6%/5%). The clinical sample was slightly older (71.5% vs 55.9% age 40+) and included less males (36% vs 49.3%).

CONCLUSIONS

Results are quite similar, although prevalences are usually higher in the clinical setting, with the exception of p-tert-butylphenol formaldehyde resin.

Multiyear Group and Medical Center Patch Test Frequency Data: Confounding Variables

Patch test frequency data have been extensively published by research groups, such as the International Contact Dermatitis Research Group, North American Contact Dermatitis Group, Dermato-Allergology Study and Research Group, and European Environmental Contact Dermatitis Research Group. As this knowledge accumulation is widely applied in clinical and public health settings, we describe confounding factors to consider when using such data for medical policy considerations. These concepts can also be used in individual reports of new allergens or series of cases. Some of these confounders may have been reported in current literature (until October 2020), whereas others have not been mentioned/considered in most group publications.

Candidate Allergens for Inclusion in the Spanish Standard Series Based on Data from the Spanish Contact Dermatitis Registry

BACKGROUND

Standard patch test series must be updated using objective data on allergen sensitization. The Spanish standard series was last updated in 2016 and the European series in 2019, and the inclusion of several emerging allergens needs to be evaluated.

MATERIAL AND METHODS

We conducted a prospective, observational, multicenter study of consecutive patients from the registry of the Spanish Contact Dermatitis and Skin Allergy Research Group (GEIDAC) who were patch tested in 2019 and 2020 with linalool hydroperoxide, limonene hydroperoxide, 2-hydroxyethyl-methacrylate, benzisothiazolinone, octylisothiazolinone, textile dye mix (TDM), sodium metabisulfite, propolis, bronopol, Compositae mix II, diazolidinyl urea, imidazolidinyl urea, decyl glucoside, and lauryl glucoside.

RESULTS

We analyzed data for 4654 patients tested with diazolidinyl urea, imidazolidinyl urea, and bronopol, and 1890 tested with the other allergens. The values for the MOAHLFA index components were 30% for male, 18% for occupational dermatitis, 15% for atopic dermatitis, 29% for hand, 6.5% for leg, 23% for face, and 68% for age > 40 years. Sensitization rates above 1% were observed for 7 allergens: linalool hydroperoxide, 2-hydroxyethyl-methacrylate, benzisothiazolinone, limonene hydroperoxide, TDM, sodium metabisulfite, and propolis. Three allergens had a current relevance rate of over 1%: linalool hydroperoxide, 2-hydroxyethyl-methacrylat, and limonene hydroperoxide. Benzisothiazolinone and TDM had a relevance rate of between 0.9% and 1%.

CONCLUSIONS

Our results indicate that 7 new allergens should be considered when extending the Spanish standard patch test series. The data from our series could be helpful for guiding the next extension of the European baseline series.

European Surveillance System on Contact Allergies (ESSCA): Characteristics of patients patch tested and diagnosed with irritant contact dermatitis

BACKGROUND

Irritant contact dermatitis (ICD) is caused by the acute locally toxic effect of a strong irritant, or the cumulative exposure to various weaker physical and/or chemical irritants.

OBJECTIVES

To describe the characteristics of patients with ICD in the population patch tested in the European Surveillance System on Contact Allergies (ESSCA; www.essca-dc.org) database.

METHODS

Data collected by the ESSCA in consecutively patch-tested patients from January 2009 to December 2018 were analyzed.

RESULTS

Of the 68 072 patients, 8702 were diagnosed with ICD (without concomitant allergic contact dermatitis [ACD]). Hand and face were the most reported anatomical sites, and 45.7% of the ICD was occupational ICD (OICD). The highest proportions of OICD were found in metal turners, bakers, pastry cooks, and confectionery makers. Among patients diagnosed with ICD, 45% were found sensitized with no relevance for the current disease.

CONCLUSIONS

The hands were mainly involved in OICD also in the subgroup of patients with contact dermatitis, in whom relevant contact sensitization had been ruled out, emphasizing the need for limiting irritant exposures. However, in difficult-to-treat contact dermatitis, unrecognized contact allergy, or unrecognized clinical relevance of identified allergies owing to incomplete or wrong product ingredient information must always be considered.

Frequency of sensitization to the individual fragrances of fragrance mix I and II according to the factors included in the MOAHLFA index

BACKGROUND

Fragrances constitute the second most frequent cause of allergic contact dermatitis in Spain.

OBJECTIVES

To determine the rate of sensitization to the individual fragrances of fragrance mix (FM) I and FM II for each of the demographic and clinical factors included in the MOAHLFA (male, occupational dermatitis, atopic dermatitis, hand dermatitis, leg dermatitis, facial dermatitis, age) index.

METHODS

We conducted a 5-year retrospective study in 23 Spanish centres. We identified the patients who had undergone patch testing with a specific fragrance series after reacting positively to fragrance markers in a baseline series. We obtained the MOAHLFA index items in this population, then calculated for each demographic and clinical factor the frequencies of sensitization to the individual fragrances of FM I and FM II.

RESULTS

A specific fragrance series was patch tested in 1013 patients. The most frequent allergens in men, women, children, and retired people were Evernia prunastri (16%), geraniol (16.6%), isoeugenol (17.9%), and geraniol (22.4%), respectively. Citral (20.5%) and hydroxyisohexyl 3-cyclohexene carboxaldehyde (HICC) (14.5%) were the most common allergens in occupational eczemas and were also associated with a large proportion of hand and facial dermatitis.

CONCLUSIONS

Frequency of sensitization to the individual fragrances of FM I and FM II varies with age, sex, affected body region, and history of occupational or atopic dermatitis.

Patch Testing With Carmine 2.5% in Petrolatum by the North American Contact Dermatitis Group, 2011-2012

BACKGROUND

Carmine is a natural red dye that may cause allergic contact dermatitis.

OBJECTIVE

The aim of this study was to analyze patch test reactions to carmine (2.5% in petrolatum) and characterize carmine-positive patients.

METHODS

This study conducted a retrospective analysis of North American Contact Dermatitis Group data compiled between 2011 and 2012.

RESULTS

Of 4240 patients patch tested to carmine, 132 (3.1%) had reactions with a final interpretation of "allergic" (positive). Carmine-positive patients were significantly more likely to be female (77.7% vs 68.3%; P = 0.0237) and have a final primary diagnosis of allergic contact dermatitis (74.8% vs 47.2%; P < 0.0001). As compared with carmine-negative patients, carmine-positive patients were significantly more likely to have involvement of all facial sites combined (48.1% vs 29.9%; P < 0.0001) and the lips (7.6% vs 3.6%; P = 0.0166). At final reading, most carmine reactions were weak (+; 64.9%). Approximately half (53.4%) were currently clinically relevant; identified sources were primarily personal care products (77.1%), especially makeup (31.4%) and lip products (8.6%).

CONCLUSIONS

Weak patch test reactions to carmine should be interpreted with caution. Allergic contact dermatitis to carmine should be suspected in women with facial and/or lip dermatitis, especially those using carmine-containing cosmetics.

Patch test results with the European baseline series and additions thereof in the ESSCA network, 2015-2018

BACKGROUND

Clinical surveillance of the prevalence of contact allergy in consecutively patch tested patients is a proven instrument to continually assess the importance of contact allergens (haptens) assembled in a baseline series.

OBJECTIVES

To present current results from the European Surveillance System on Contact Allergies, including 13 countries represented by 1 to 11 departments.

METHODS

Anonymized or pseudonymized patch test and clinical data from various data capture systems used locally or nationally as transferred to the Erlangen data centre were pooled and descriptively analysed after quality control.

RESULTS

In the 4 years (2015-2018), data from 51 914 patients patch tested with the European baseline series (EBS) of contact allergens were analysed. Contact allergy to nickel was most frequent (17.6% positive), followed by contact allergy to fragrance mix I (6.9%), methylisothiazolinone (MI; 6.2%), and Myroxylon pereirae resin (balsam of Peru; 5.8%).

CONCLUSIONS

While the prevalence of MI contact allergy decreased substantially following regulatory intervention, the persistently high levels of allergy to metals, fragrances, other preservatives, and rubber chemicals point to problems needing further research and, potentially, preventive efforts. Results with national additions to the baseline series provide important information on substances possibly to be considered for inclusion in the EBS.

Developing a cosmetic series: Results from the ESSCA network, 2009-2018

BACKGROUND

There is considerable variability across European patch test centres as to which allergens are included in local and national cosmetics series.

OBJECTIVES

To propose a standardized, evidence-based cosmetic series for Europe based on up-to-date analysis of relevant contact allergens.

METHODS

We collated data from the European Surveillance System on Contact Allergies (ESSCA) from 2009 to 2018 to determine which cosmetic allergens produce a high yield of contact allergy. Contact allergens with a prevalence of >0.3% that were considered relevant were included. Rare contact allergens were excluded if deemed no longer relevant or added to a supplemental cosmetic series for further analysis.

RESULTS

Sensitization prevalences of 39 cosmetic contact allergens were tabulated. Thirty of these allergens yielded >0.3% positive reactions and are therefore included in our proposed European cosmetic series. Six were considered no longer relevant and therefore excluded. Three were included in a supplementary European cosmetic series. An additional nine allergens were included in either the core or supplemental European cosmetic series following literature review.

CONCLUSION

We have derived a potential European cosmetic series based upon the above methods. This will require ongoing investigation based upon the changing exposure profiles of cosmetic allergens as well as new and evolving substances.

Cross-Reactivity of Palladium in a Murine Model of Metal-Induced Allergic Contact Dermatitis

Metal allergy is usually diagnosed by patch testing, however, the results do not necessarily reflect the clinical symptoms because of cross-reactivity between different metals. In this study, we established the novel mouse model of cross-reactive metal allergy, and aimed to elucidate the immune response in terms of T-cell receptor repertoire. This model was classified into two groups: the sensitization to nickel and challenge with palladium group, and the sensitization to chromium and challenge with palladium group. This model developed spongiotic edema with intra- and peri-epithelial infiltration of CD4⁺ T cells in the inflamed skin that resembles human contact dermatitis. Using T cell receptor analysis, we detected a high proportion of T cells bearing Trav8d-1-Traj49 and Trav5-1-Traj37 in the Ni- and Cr-sensitized Pd-challenged mice. Furthermore, mucosal-associated invariant T cells and invariant natural killer T cells were also detected. Our results indicated that T cells bearing Trav8d-1-Traj49 and Trav5-1-Traj37 induced the development of palladium-cross reactive allergy, and that mucosal-associated invariant T and invariant natural killer T cells were also involved in the cross-reactivity between different metals.

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.

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.

Trend of relevant contact allergens of the feet in Spain over a period of 10 years

INTRODUCTION

Allergic contact dermatitis (ACD) of the feet accounts for approximately 10% of all patch tested patients.

OBJECTIVE

To study the clinical profile of patients with feet dermatitis and relevant contact allergens in Spain over a 10-year period.

METHODS

Retrospective observational study of patients with suspected ACD from the GEIDAC (Spanish Research Group on Contact Dermatitis and Cutaneous Allergy) baseline series from eight hospitals in Spain between 2004 and 2014. The clinical data collected from each patient were age, sex, occupation, history of atopic dermatitis, and eczema location.

RESULTS

A total of 450 cases clinically presented dermatitis affecting the feet; of these, 41% of were males and 5.6% were suspected to be of occupational origin. As much as 47% were diagnosed with ACD, 20% with atopic dermatitis/dyshidrotic eczema, and 5% with psoriasis. The "feet group" included statistically significantly more females in the age range of 21 to 60 years. The most frequent relevant contact allergens were potassium dichromate, cobalt(II) chloride, p-tert-butylphenol formaldehyde resin, mercapto mix, and mercaptobenzothiazole.

CONCLUSIONS

ACD is the most frequent clinical diagnosis of feet dermatitis in our series. The most frequent allergens are similar to those published in other series of foot ACD in Europe and the trend has not changed in the studied decade.

Contact urticaria: Frequency, elicitors and cofactors in three cohorts (Information Network of Departments of Dermatology; Network of Anaphylaxis; and Department of Dermatology, University Hospital Erlangen, Germany)

BACKGROUND

Contact urticaria (CU) is an infrequent, mostly occupational disease that may be life-threatening (CU syndrome stage 4).

OBJECTIVES

To identify the current frequency, elicitors and cofactors of CU.

PATIENTS

Three cohorts were retrospectively analysed for CU: (a) patients from the Information Network of Departments of Dermatology (IVDK) database (2000-2014; n = 159 947); (b) patients from an allergy unit (Department of Dermatology, University Hospital Erlangen, 2000-2015; n = 4741); and (c) patients from the Anaphylaxis Registry (2007-2015: 6365 reported cases, including 2473 patients with Ring and Messmer grade III-IV reactions) for severe cases with skin/mucosal manifestations occurring at the workplace vs cases not occurring at the workplace (n = 68 vs n = 1821).

RESULTS

Four hundred and forty-eight CU patients (0.28%) were diagnosed in the IVDK cohort, and 16 (0.34%) (10 of immunological aetiology, and 6 of non-immunological aetiology) in the Erlangen cohort. The most frequent elicitors in the IVDK cohort were cosmetics, creams, sun protection agents (although these were less frequent in CU patients than in controls without CU; 26.8% vs 35.6%, P < .0001), and gloves (significantly more frequent in CU patients than in controls; 18.1% vs 6.5%, P < .0001). The most frequent elicitors in the Erlangen cohort were natural rubber latex and sorbic acid. Among the MOAHLFA index characteristics, in both cohorts occupational disease was more common in CU patients than in patients without CU. CU was significantly associated with allergic rhinitis and allergic asthma. Wet work was a relevant cofactor. In the Anaphylaxis Registry, 19 cases (0.3%) were identified with severe reactions including skin symptoms at the workplace linked to common occupational elicitors.

CONCLUSIONS

CU is a rare occupational skin manifestation with a frequency of <0.4% in the examined patients; it may, however, progress to anaphylaxis. Preventive measures are important, and should take into account the identified elicitors and cofactors.

Methyl Green-Pyronine Staining of Porcine Organotypic Skin Explant Cultures: An Alternative Model for Screening for Skin Irritants

We describe a new alternative method for screening for skin irritants by using fresh intact porcine skin biopsies. Test chemicals were applied to the epidermis of the biopsies, which were then incubated for different times in tissue culture medium at 37°C and with 5% carbon dioxide. A decrease in epidermal keratinocyte RNA staining, visualised in frozen sections by using a modified methyl-green pyronine (MGP) staining procedure, was employed as a marker of irritancy. If a decrease in epidermal RNA was observed after incubation for 4 hours (strong irritant), the chemical had an MGP score of 3; if after incubation for 24 hours (moderate irritant), the MGP score was 2; and if after incubation for 48 hours (weak irritant), the MGP score was 1. If no keratinocyte cytotoxicity was observed after incubation for 48 hours, the chemical was classified as non-irritant (MGP score = 0). At least three ears were used per chemical. The average MGP score was used to classify the chemical. Based on the MGP score for 20% sodium dodecyl sulphate, chemicals classified as strong or moderate irritants by using the MGP test were grouped together as category R38 chemicals. Weak irritants or non-irritants were not classified (NC). The MGP staining correctly identified 23 of 25 skin irritants for which reference data were available.

European Surveillance System on Contact Allergies (ESSCA): Contact allergies in relation to body sites in patients with allergic contact dermatitis

Background

Analyses of the European Surveillance System on Contact Allergies (ESSCA) database have focused primarily on the prevalence of contact allergies to the European baseline series, both overall and in subgroups of patients. However, affected body sites have hitherto not been addressed.

Objective

To determine the prevalence of contact allergies for distinct body sites in patients with allergic contact dermatitis (ACD).

Methods

Analysis of data collected by the ESSCA (www.essca‐dc.org) in consecutively patch tested patients, from 2009 to 2014, in eight European countries was performed. Cases were selected on the basis of the presence of minimally one positive patch test reaction to the baseline series, and a final diagnosis of ACD attributed to only one body site.

Results

Six thousand two hundred and fifty‐five cases were analysed. The head and hand were the most common single sites that ACD was attributed to. Differences between countries were seen for several body sites. Nickel, fragrance mix I, cobalt and methylchloroisothiazolinone/methylisothiazolinone were the most frequent allergens reported for various body sites.

Conclusions

Distinct allergen patterns per body site were observed. However, contact allergies were probably not always relevant for the dermatitis that patients presented with. The possibility of linking positive patch test reactions to relevance, along with affected body sites, should be a useful addition to patch test documentation systems.

Contact sensitization to hydroperoxides of limonene and linalool: Results of consecutive patch testing and clinical relevance

Background

Hydroperoxides of limonene and linalool are potent sensitizers.

Objectives

To investigate the prevalence of contact allergy to both hydroperoxides of limonene and hydroperoxides of linalool, to report clinical relevance, and to investigate patient demographics.

Methods

A total of 821 patients (35.6% male, mean age 42.4 years ± 17.8 years) were consecutively patch tested with our departmental baseline series and our fragrance series, including hydroperoxides of limonene 0.3% pet. and hydroperoxides of linalool 1.0% pet. The clinical relevance was assessed for all positive reactions.

Results

Positive patch test reactions to hydroperoxides of limonene and to hydroperoxides of linalool were observed in 77 patients (9.4%, 95% confidence interval [CI]: 7.4%‐11.4%) and in 96 patients (11.7%, 95%CI: 9.5%‐13.9%), respectively; 38 of these patients (4.6%, 95%CI: 3.2%‐6.0%) reacted to both. Most reactions were considered to be possibly or probably clinically relevant (66.3% and 68.8%, respectively), and a small proportion were deemed to be of certain clinical relevance (18.2% and 19.8%, respectively).

Conclusion

As compared with previous studies, high numbers of positive reactions to both hydroperoxides of limonene and hydroperoxides of linalool were observed, the majority of which were clinically relevant, supporting their inclusion in the European baseline series.

Epidemiology of nickel sensitivity: Retrospective cross-sectional analysis of North American Contact Dermatitis Group data 1994-2014

BACKGROUND

Nickel is a common allergen.

OBJECTIVE

To examine the epidemiology of nickel sensitivity in North America.

METHODS

Retrospective, cross-sectional analysis of 44,097 patients patch tested by the North American Contact Dermatitis Group from 1994 to 2014. Nickel sensitivity was defined as a positive patch test for nickel. We evaluated the frequency of nickel sensitivity and patient demographics. For each positive reaction to nickel, we tabulated clinical relevance, occupational relatedness, and exposure sources.

RESULTS

The average frequency of nickel sensitivity was 17.5% (1994-2014). Nickel sensitivity significantly increased over time (from 14.3% in 1994-1996 to 20.1% in 2013-2014 [P < .0001]). Nickel-sensitive patients were significantly more likely to be female, young, nonwhite, and atopic (have eczema and asthma) and/or have dermatitis affecting the face, scalp, ears, neck, arm, or trunk (P values ≤ .0474). Overall, 55.5% of reactions were currently clinically relevant; this percentage significantly increased over time (from 44.1% in 1994-1996 to 51.6% in 2013-2014 [P < .0001]). The rate of occupational relatedness was 3.7% overall, with a significant decrease over time (from 7.9% in 1994-1996 to 1.9% in 2013-2014 [P < .0001]). Jewelry was the most common source of nickel contact.

LIMITATIONS

Tertiary referral population.

CONCLUSIONS

Nickel allergy is of substantial public health importance in North America. The frequency of nickel sensitivity in patients referred for patch testing has significantly increased over a 20-year period.