The European baseline series and recommended additions: 2019

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.

The European baseline series: Criteria for allergen inclusion (with reference to formaldehyde releasers)

Existing criteria for inclusion in the European baseline series are summarized. Additional criteria are developed to aid decision making where the current criteria do not yield an unequivocal result. These include a consideration of whether an allergen (hapten) is better placed in a special series and the frequency with which an allergen cross-reacts with existing markers in the baseline series.

Should methyldibromo glutaronitrile continue to be used in the European baseline Series? A REIDAC national cross-sectional study

BACKGROUND

Methyldibromo glutaronitrile (MDBGN) was one of the most frequent and relevant allergens found in patch testing at the beginning of this century. In 2008, this preservative was banned from cosmetics in Europe and ever since the prevalence of contact allergy to MDBGN has progressively decreased. Despite that gradual decline, MDBGN is still patch-tested in most baseline series. This study assessed the frequency of MDBGN sensitization, epidemiological characteristics of allergic patients, and the relevance of positive patch tests in a nationwide Spanish registry (REIDAC).

PATIENTS AND METHODS

We evaluated consecutively patch-tested patients in all participating centres. Using these data, we calculated the proportion of patients with positive patch tests to MDBGN from June 2018 to June 2020 and evaluated the relevance of the positive patch tests.

RESULTS

One hundred and fourteen out of 5072 (2.24 %) tested patients were sensitized to MDBGN. Clinical current relevance was confirmed in only one case.

CONCLUSION

Although the frequency of contact allergy to MDBGN remains high, no clinical significance was found in most of these patients (5072 tests needed to obtain one relevant positive result). The clinical usefulness of this allergen seems weak and its continued inclusion in the European baseline series is questionable.

HIGHLIGHTS

In 2008 methyldibromo glutaronitrile (MDBGN) was banned from cosmetics in Europe and since then, the prevalence of allergy to it has progressively decreased. Nevertheless, it is still being tested in European baseline series. This study assessed the frequency of MDBGN sensitization, epidemiological characteristics of allergic patients as well as the relevance of positive patch tests in a nationwide registry (REIDAC). The frequency of allergy to MDBGN remains high, but no clinical significance was found. Most of these patients are aged >40 years and probably represent historical sensitizations.

Associated positive patch test reactions to standard contact allergens: 10-year data from the Slovenian E-Surveillance System

BACKGROUND

A considerable share of patients tested with a baseline patch test series respond with a positive reaction to more than one allergen, and some associations between synchronous positive reactions to distinct baseline patch allergens have been described in the literature.

OBJECTIVES

To evaluate the prevalence of sensitization to haptens of the European baseline series as well as the prevalence of oligosensitization and polysensitization and the most significant associated positive patch test reactions in Slovenia.

METHODS

Patch testing data collected by the Slovenian E-Surveillance System from January 2008 to December 2017 were retrospectively analysed.

RESULTS

Of a total of 15 171 patients analysed, 39.29% showed at least one positive reaction. The highest prevalences were noted for metals (nickel[II]sulfate hexahydrate: 16.33%) and fragrances (fragrance mix I: 6.70%). The correlation analysis showed the strongest correlation between mercapto mix and 2-mercaptobenzothiazole (61.2%), fragrance Mix II and hydroxyisohexyl 3-cyclohexene carboxaldehyde (50.5%), and potassium dichromate and cobalt(II) chloride hexahydrate (33.3%).

CONCLUSIONS

Sensitization prevalences to the most common haptens were described, and their strongest correlations on a national level quantified. A comparison with other European results confirms already known associations between allergens in terms of cross-reactivity.

Nickel: Intrinsic Skin Sensitization Potency and Relation to Prevalence of Contact Allergy

Nickel remains the most commonly identified contact allergen. However, it has proven difficult to demonstrate significant skin-sensitizing activity for nickel in toxicology tests, which typically have indicated a weak skin sensitization potential. Information indicates that in vivo assays are not predictive of dermal sensitization hazard or potency for nickel due to a human-specific mechanistic route for nickel sensitization that animals lack. A similar rationale will apply to in vitro alternatives-although these currently have limited ability to determine intrinsic potency. Generally, in silico methods are not designed for metal allergens and cannot contribute to the analysis. For ethical reasons, human experimental work has been limited, with a single study suggesting moderate potency. Accordingly, it seems reasonable to conclude that the high frequency of contact allergy to nickel in humans is a function of both its intermediate potency coupled with a high level of dermal exposure, particularly to damaged/inflamed skin.

Sensitization to benzyl salicylate and other allergens in patients with frontal fibrosing alopecia

BACKGROUND

Contact sensitization is frequent among patients with frontal fibrosing alopecia (FFA) (52%-76%).

OBJECTIVE

To evaluate the frequency of sensitization/photosensitization in an FFA population.

METHODS

A population of FFA patients were patch tested (Spanish Contact Dermatitis Research Group [GEIDAC] baseline; cosmetic and fragrance series), and photopatch tested (sunscreen series).

RESULTS

Thirty-six patients (mean age: 64.6 years; 35/36: women) were studied. A history of dermatitis was recorded in 69.4% (frequently involving the face). Overall, 80.5% patients showed positive patch-test reactions. The most frequently positive allergens were nickel sulfate (25%), benzyl salicylate (22%), gallates (16.6%), propolis (16.6%), and limonene hydroperoxides (13.8%). Benzyl salicylate was likely relevant to the dermatitis (labeled on personal care products and most patients reporting clinical improvement with allergen avoidance). Patch tests with sunscreens showed positive reactions to 11 materials (five patients). Photopatch tests were positive in one case.

CONCLUSION

We speculate a possible relationship between sensitization to benzyl salicylate and FFA. Hypothetically, the most likely explanation is that sensitization to benzyl salicylate involving FFA patients is a consequence of increased exposure to it. It is unclear whether allergen avoidance may impact the prognosis of alopecia. However, it seems to significantly improve the patients´ quality of life by lessening dermatitis and pruritus.

Topical corticosteroid allergy: Results of sequential testing to a corticosteroid series in New Zealand

BACKGROUND

Our institution tests the European Baseline Series (EBS) and a steroid series sequentially in all patients presenting for patch testing. The rate of steroid sensitization in New Zealand has not previously been documented.

OBJECTIVES

To investigate the rate of corticosteroid sensitization and assess additional benefit of testing the full steroid series over the steroid allergy markers in the EBS.

METHODS/PATIENTS

Retrospective analysis of all patient demographics and patch test results over a 5-year period (2014 to 2019) was performed at a tertiary patch test clinic in Auckland, New Zealand.

RESULTS

A total of 319 patients completed patch testing, and 4.4% were sensitized to one or more corticosteroids. As much as 79% of positive reactions were of current relevance; 11/14 reactions were to tixocortol pivalate or budesonide. The "number needed to test" to detect one additional case of corticosteroid sensitization by using the full corticosteroid series over the EBS alone was 107.

CONCLUSIONS

Although corticosteroid sensitization was not uncommon in our population, the results suggest that sequential testing with the corticosteroid markers (budesonide and tixocortol) in the standard series alone is adequate. The additional corticosteroid series should be added if the markers are positive or where there is a clinical suspicion of corticosteroid allergy.

Hand eczema in children referred for patch testing: North American Contact Dermatitis Group Data, 2000-2016

BACKGROUND

Little is known about the aetiologies and relevant allergens in paediatric patients with hand eczema (HE).

OBJECTIVES

To characterize the aetiologies and determine the proportion of positive and currently relevant allergens in children/adolescents (age < 18 years) with HE referred for patch testing.

METHODS

A retrospective analysis (2000-2016) of North American Contact Dermatitis Group data was performed.

RESULTS

Of 1634 paediatric patients, 237 (14·5%) had involvement of the hands. Final physician diagnoses included allergic contact dermatitis (49·4%), atopic dermatitis (37·1%) and irritant contact dermatitis (16·9%). In multivariable logistic regression models, employment was the only association with increased odds of any HE or primary HE. Children with HE vs. those without HE had similar proportions of positive patch tests (56·1% vs. 61·7%; χ² -test, P = 0·11). The five most common currently relevant allergens were nickel, methylisothiazolinone, propylene glycol, decyl glucoside and lanolin. In multivariable logistic regression models of the top 20 relevant allergens, HE was associated with significantly higher odds of currently relevant reactions to lanolin, quaternium-15, Compositae mix, thiuram mix, 2-mercaptobenzathiazole and colophony. The allergens with the highest mean significance-prevalence index number were methylisothiazolinone, carba mix, thiuram mix, nickel and methylchloroisothiazolinone/methylisothiazolinone.

CONCLUSIONS

Children with HE who were referred for patch testing had a high proportion of positive patch tests, which was similar to the proportion found in children without HE. Children with HE had a distinct and fairly narrow profile of currently relevant allergens.

Value of photo assessment in late patch test readings-A multicenter study from six European patch test clinics

BACKGROUND

It is recommended that patch test readings include a day (D)7 reading. Substitution of the D7 reading with a photo may be a valid option.

OBJECTIVES

To compare the sensitivity of digital photos at D7 to clinical readings, to assess the number of positive reactions appearing at D7 only (late reactions), and after D7 only (delayed reactions).

METHODS

Patients patch tested in six European clinics were instructed to forward photos of the patch test reactions to the respective clinics at D7 (before attending the clinic) and at D21. Only allergens in the baseline series or TRUE Test were included in the data analysis.

RESULTS

Two hundred ninety-three of 629 patients had a total of 599 positive reactions, with 6.3% occurring at D7 only. When substituting the D7 reading with a photo (90% submitted), 26.3% of late reactions were missed and nine false-positive reactions were found. Delayed reactions were detected in four patients at D21 (65.3% submitted).

CONCLUSION

Our data show that if the D7 reading is not performed, 6.3% of positive reactions from the baseline series would be missed, and if substituting the D7 reading by digital photo, 26.3% late reactions would be missed. Delayed reactions seemed rare.

Changes in Chinese patch testing practices over 13 years: Updated cross-sectional survey and possible international implications

BACKGROUND

Patch testing, the standard method for diagnosing allergic contact dermatitis, has been utilized for over 30 years in China. A 2006 survey found that patch testing was widespread among Chinese dermatologists, but the practice and perceptions were unsatisfactory.

OBJECTIVE

To evaluate the current situation of patch testing practice and perception, we resurveyed Chinese dermatologists.

METHODS

A cross-sectional survey of Chinese dermatologists was conducted by electronic questionnaires at the 15th National Congress of Dermatology in November 2019.

RESULTS

There were 2199 valid questionnaires collected. About 75% of dermatologists performed patch testing; the majority (59.2%) utilized the baseline (standard) allergen series made in China; others used TRUE Test or the Chemotechnique Diagnostics series, a greater share compared with 2006. Most (92.8%) performed only one single reading, more than 2006. About two-thirds offered patient education after patch testing, but only 27% were executed by trained dermatologists. Dermatologists from regional hospitals more likely performed patch testing and had better perception of patch testing. The majority (88.1%) had received patch testing training, which however did not significantly improve dermatologists' perception.

CONCLUSIONS

There was an insignificant improvement in practice and perception of dermatologists compared with 2006. Further education and studies should be conducted. Similar surveys in other countries would be of interest.

Concomitant positive patch test reactions in FreeStyle-allergic patients sensitized to isobornyl acrylate

BACKGROUND

Concomitant positive patch test reactions in patients sensitized to isobornyl acrylate (IBOA) have rarely been documented.

OBJECTIVES

To report concomitant sensitizations in patients with allergic contact dermatitis (ACD) from the glucose sensor FreeStyle Libre and sensitized to IBOA.

METHODS

In 2019, 26 patients with suspected ACD from FreeStyle Libre were patch tested to a baseline series and to a (meth) acrylate series containing IBOA and 2-phenoxyethyl acrylate (PEA) 0.1% pet. Diabetes devices and patch test preparations were analyzed with gas chromatography - mass spectrometry (GC-MS) for the presence of IBOA and PEA.

RESULTS

Of the 26 patients, 18 (69%) were sensitized to IBOA, and eight (44%) and 11 (61%) of these were co-sensitized to sesquiterpene lactones and fragrances, respectively. Ten patients (56%) were co-sensitized to PEA, which, contrary to IBOA, could not be detected in any device. The PEA test material was shown to be contaminated with IBOA.

CONCLUSIONS

Contact allergy to IBOA appears to be declining and IBOA-sensitized patients are most often co-sensitized to sesquiterpene lactones and fragrances. Vigilance is required when patch testing (acrylate) materials obtained from industry, as these might be contaminated and, hence, alter the results and their interpretation.

The Effect of Atopy in the Prevalence of Contact Sensitization: The Experience of a Greek Referral Center

Contact dermatitis is a well-known skin condition, which is related to stimuli and environmental exposure to chemicals, affecting all ages as well as both genders. In the present work, we attempt to investigate the patterns of contact sensitization, with respect to the personal history of atopy (AT), in Greece in a large number of allergens, using patch testing. The retrospective analysis included clinical routine data of 1978 patients collected from 2014 to 2016 in the Laboratory of Patch Testing, National Referral Centre of Occupational Dermatoses. Sensitization, in all cases, was tested with 28 allergens of the European baseline series as adjusted to our local circumstances and clinical experience. A total population of 1978 patients was evaluated, with a male-to-female ratio of 0.45 (1359 females/619 males). From our patient cohort, 693 (35%) patients were evaluated with a history of atopy, while 1285 (65%) were nonatopic. The five most prevalent allergens in the total population without AT were nickel sulphate 5% (15.47%), fragrance mix (I) 8% (9.10%), balsam of Peru (6.47%), cobalt chloride 1% (4.70%), and thiomersal 0.1% (4.10%). Respectively, in the total population with AT, the five most prevalent allergens were nickel sulphate 5% (10.36%), fragrance mix (I) 8% (5.11%), balsam of Peru (3.29%), thiomersal 0.1% (3.03%), and cobalt chloride 1% (2.78%). Contact dermatitis surveillance is of great importance towards the clinical and systematic understanding of the disease. Further studies should be directed towards that end, in order to facilitate more effective health policies.

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.

Medical devices in allergy practice

Medical devices provide people with some health benefits in terms of diagnosis, prevention, treatment, and monitoring of disease processes. Different medical specialties use varieties of medical devices more or less specific for them. Allergology is an interdisciplinary field of medical science and teaches that allergic reactions are of systemic nature but can express themselves at the level of different organs across the life cycle of an individual. Subsequently, medical devices used in allergology could be regarded as: 1) general, servicing the integral diagnostic and management principles and features of allergology, and 2) organ specific, which are shared by organ specific disciplines like pulmonology, otorhinolaryngology, dermatology, and others. The present position paper of the World Allergy Organization (WAO) is meant to be the first integral document providing structured information on medical devices in allergology used in daily routine but also needed for sophisticated diagnostic purposes and modern disease management. It is supposed to contribute to the transformation of the health care system into integrated care pathways for interrelated comorbidities.

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.

In vivo demonstration of immunologic cross-reactivity to octylisothiazolinone in patients primarily and strongly sensitized to methylisothiazolinone

BACKGROUND

Notwithstanding that concomitant exposure to different isothiazolinone derivatives may result in concomitant sensitization, clinical and animal studies have suggested cross-reactivity between these derivatives, notably between methylisothiazolinone (MI) and octylisothiazolinone (OIT).

OBJECTIVE

To investigate if patients sensitized to MI show cross-reactions to OIT and/or to benzisothiazolinone (BIT) by applying the concept of the re-test method.

PATIENTS AND METHODS

From March to October 2019 consecutive patients were patch tested with MI 0.2% aqueous in duplicate at the two lower corners of both shoulder blades. Patients sensitized to MI, but not to OIT 0.1% petrolatum (pet.) nor to BIT 0.1% pet., were re-tested, 2 months later, with the latter two derivatives at the skin sites where the MI reactions had fully disappeared.

RESULTS

Of 116 patients, 15 (13%) were sensitized to MI, eight of these not sensitized to BIT nor to OIT. Of these, seven patients, all (very) strongly sensitized to MI, were re-tested: five patients showed positive patch test reactions to OIT 0.1% pet.; one patient to OIT 0.1% pet. and BIT 0.1% pet.; and one other patient showed no reactions.

CONCLUSION

This study suggests that patients primarily and strongly sensitized to MI may show immunologic cross-reactions to OIT, and to a far lesser extent to BIT.

What is in? What is out? Updating the British Society for Cutaneous Allergy facial series

BACKGROUND

Allergic contact dermatitis (ACD) to cosmetics is widely reported. To ensure we are accurately diagnosing ACD, patch test series should be continually reviewed to identify relevant and emerging allergens and highlight those that are outdated. The current British Society for Cutaneous Allergy (BSCA) facial series recommends 26 allergens and was last modified in 2012.

OBJECTIVES

To review and update the BSCA facial series.

METHODS

We retrospectively reviewed the results from 12 UK and Ireland patch test centres' facial series from January 2016 to December 2017. We recorded the number of allergens tested in each centre and the detection rate for each allergen. Using a 0·3% positive rate as the inclusion threshold, we established which allergens in the BSCA facial series had positive patch test rates < 0·3% and > 0·3%. Allergens not in the BSCA facial series that had a positive patch test rate > 0·3% were identified.

RESULTS

Overall, 4224 patients were patch tested to the facial series. The number of allergens included in individual centres' facial series ranged from 24 to 66, with a total of 103 allergens tested across all centres. Twelve of the 26 allergens in the BSCA facial series had a positive patch test rate < 0·3% and 14 had a rate > 0·3%. Twenty-five allergens not recommended in the BSCA facial series had a positive patch test rate > 0·3%.

CONCLUSIONS

This audit has highlighted the significant variation in practice that exists among patch test centres, despite a recommended facial series. The BSCA facial series has been updated and now contains 24 allergens. Fifteen allergens remain, 11 allergens have been dropped and nine new allergens have been added.

Contact Allergy-Emerging Allergens and Public Health Impact

Contact allergy (sensitisation) and allergic contact dermatitis (ACD) resulting from it have a considerable public health impact. For the present review, all pertinent articles were systematically searched via Medline and Web of Science™; additionally, all available issues of the journals "Contact Dermatitis" and "Dermatitis" were manually searched, covering the years 2018-2019, thereby extending and re-focusing a previous similar review. New allergens, or previously described allergens found in a new exposure context or of other current importance, are described in sections according to substance classes, e.g., metals, preservatives, fragrances. As a common finding in many investigations, a lack of information on product composition has been noted, for instance, regarding a newly described allergen in canvas shoes (dimethylthiocarbamylbenzothiazole sulfide) and, most notably, absence of co-operation from manufacturers of glucose-monitoring devices and insulin pumps, respectively. These latter devices have been shown to cause severe ACD in a considerable number of diabetic patients caused by the liberation of isobornyl acrylate and N,N'-dimethylacrylamide, respectively, as demonstrated by an international collaboration between dermatologists and chemists. Improved and complete ingredient labelling for all types of products, and not just cosmetics, must be put on the legislative agenda.

Methylchloroisothiazolinone and/or Methylisothiazolinone Contact Allergies in Thailand

BACKGROUND

Methylchloroisothiazolinone, in combination with methylisothiazolinone (MCI/MI), and MI alone are common preservatives. The incidences of MCI/MI and MI-alone contact allergies have risen markedly worldwide, leading to changes in their use in products.

OBJECTIVES

The aim of the study was to determine the incidences of positive patch test reactions and factors associated with MCI and/or MI contact allergies during the recent decade in Thailand.

METHODS

Medical records of patients who underwent patch testing at Siriraj Hospital from 2009 to 2018 were retrospectively reviewed. The incidences of positive reactions, histories, and clinical data of MCI/MI and MI-alone contact allergy patients were analyzed.

RESULTS

Of 2789 patients undergoing patch testing, most were female (76.1%). The mean ± SD age was 42.7 ± 15.7 years. Positive reactions to MCI/MI increased from 2009 to 2016 before declining. The MCI/MI contact allergy was most common in females, middle-aged patients, and those with metal allergy histories, with the hands and arms being the predominant sites. However, MI-alone contact allergy was more common in males and mainly at the trunk. Its incidence significantly declined for the last 5 years.

CONCLUSIONS

The incidences of MCI/MI and MI-alone contact allergies began to decline because the Food and Drug Administration Thailand regulations restricted their use. The risk factors for the allergies reported in this study provide important information for patient care.