Recommendation to include methyldibromo glutaronitrile in the European standard patch test series

High prevalence but no current clinical relevance of methyldibromo glutaronitrile since its ban in Turkey in 2015

BACKGROUND

Regulatory actions significantly reduced methyldibromo glutaronitrile (MDBGN)-induced allergic contact dermatitis (ACD) from cosmetics in Europe. Turkey banned MDBGN in 2015.

OBJECTIVES

To assess sensitization and ACD rates to MDBGN before and after its ban in Turkey.

METHODS

Data from 2653 consecutively patch tested patients between 1996 and 2023 with MDBGN 0.1% pet. (n = 573) or 0.2%-0.3% pet. (n = 1310) or 0.5% pet. (n = 770) were analysed. MDBGN was tested as MDBGN/phenoxyethanol (PE) in 1434 patients.

RESULTS

The sensitization prevalence was 1.7% (45/2653), peaking at 5.3% in 2018 and 2023 with MDBGN 0.3% pet. There was a two-fold male predominance, with patients exclusively ≥20 years old. None of the patients reacted to PE. ACD occurred in 0.7% (19/2653), mainly affecting hands and linked to non-occupational exposure (78.9%), particularly from rinse-off/leave-on cosmetics. The pattern of 'middle-aged men with hand eczema and fragrance allergy' was particularly notable. Occupational ACD was rare (21.1%), occurring mainly in hairdressers from hair gel. Positive reactions with current clinical relevance dropped from 48.3% (1996-2014) to zero after 2015 (p < 0.001).

CONCLUSIONS

The ban effectively reduced MDBGN-induced ACD in Turkey, yet the prevalence of positive patch test reactions remains high, likely due to past exposures or other undisclosed sources. We suggest continued testing of MDBGN in the EBS in Turkey.

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.

Young individuals with atopic disease and asthma or rhinoconjunctivitis may have clinically relevant contact allergies

BACKGROUND

Children and adolescents with atopic disease who have allergic asthma and/or rhinitis with and without atopic dermatitis may have hidden, clinically relevant contact allergies.

OBJECTIVE

The objective of this study was to survey contact allergies in children and adolescents who had been offered allergen-specific immunotherapy and accepted (exposed)/not accepted (unexposed) such treatment.

METHODS

Thirty-seven exposed and 24 unexposed individuals with atopic disease were patch tested with a standard series supplemented with aluminum chloride hexahydrate, an empty Finn Chamber, and 8 antigen preparations.

RESULTS

In the exposed group, 18 allergies were detected in 13 individuals with atopic disease when excluding reactions to aluminum and antigen preparations, whereas the corresponding figures for the unexposed group were 9 and 6, respectively (non-significant difference). Independent of the allergen-specific immunotherapy, significantly more (P = 0.013) individuals with atopic dermatitis had at least 1 contact allergy. Clinically relevant allergies were represented by sesquiterpene lactone mix, para-tertiary butylphenol-formaldehyde resin, tixocortol pivalate, and colophony.

CONCLUSIONS

Clinically relevant contact allergies are not uncommon in children and adolescents with atopic disease, which is why patch testing always should be considered in the management of dermatitis in individuals with atopic disease.

There is an association between contact allergy to aluminium and persistent subcutaneous nodules in children undergoing hyposensitization therapy

BACKGROUND

The development of persistent itchy nodules at the injection site following hyposensitization therapy with aluminium-precipitated antigen extract has been described in several reports. Occasionally, contact allergy to aluminium has been reported in individuals with such nodules.

OBJECTIVES

To investigate if hyposensitization therapy can induce contact allergy to aluminium and examine if there is any association between persistent subcutaneous nodules and aluminium allergy.

PATIENTS/METHODS

Sixty-one children with allergic asthma and/or allergic rhinitis participated in the study of whom 37 had had hyposensitization therapy. The study consisted of a non-clinical part based on a questionnaire and a clinical part with a physical examination, self-assessment of itching, and patch testing. To secure an unbiased evaluation of possible reactions, the investigators were blinded.

RESULTS

Contact allergy to aluminium was found in eight participants, all in the exposed group (8/37 versus 0/24, P = 0.02). Examination showed nodules on the upper arms in 13 participants, all in the group exposed to hyposensitization therapy. Nodules were over-represented in patients with contact allergy to aluminium.

CONCLUSIONS

There was a statistically significant association between contact allergy to aluminium and persistent subcutaneous nodules in children who had had hyposensitization therapy.

The European Surveillance System of Contact Allergies (ESSCA): results of patch testing the standard series, 2004

BACKGROUND

The European Surveillance System on Contact Allergies (ESSCA) began in 2001 as project funded by a European Union grant to monitor and evaluate contact sensitization (CS) based on clinical data collected by participating European dermatology departments.

OBJECTIVES

ESSCA aims to detect trends in CS in an international patch test population, monitoring the frequency of CS to (standard series) allergens, evaluating the effectiveness of intervention (e.g. governmental regulations) and improving standardization of the patch test procedure on an international level.

METHODS

In 2004, 31 ESSCA dermatology departments in 11 European countries collected patch test results and medical histories of patients tested with the European Standard Series (ESS) or a local standard allergen series using the multilingual Winalldat/ESSCA database, the German Winalldat/Information Network of Departments of Dermatology (IVDK) database or a locally created database including the items of the ESSCA 'minimal data set'. Data were sent to the ESSCA data centre where they were imported, pooled, examined for quality and subsequently analysed.

RESULTS

The departments patch tested 11 643 patients with a standard series, and 44% of the patients tested positive to one or more substances of the ESS. Nickel sulphate, the fragrance mix, Myroxylon pereirae resin, cobalt chloride, potassium dichromate, methyldibromoglutaronitrile and paraphenylenediamine are (still) the most important allergens detected. Several additional substances tested on consecutive patients in some clinics were also examined. Among these allergens, propolis and Compositae mix had a relatively high CS prevalence.

CONCLUSIONS

The expanding ESSCA network continues to provide up-to-date information regarding the pattern of CS diagnosed in participating departments across Europe.

High frequency of contact allergy to gold in patients with endovascular coronary stents

BACKGROUND

Stent implantation is an effective method for treatment of atherosclerotic disease. Factors predisposing to in-stent restenosis are still largely unknown. Contact allergy to metal ions eluted from the stent has been suggested to be a risk factor.

OBJECTIVES

To explore whether there is a possible induction of contact allergy to metals used in stents among patients with a stainless steel stent containing nickel (Ni stent) and patients with a gold-plated stent (Au stent).

METHODS

Adults (n = 484) treated with coronary stent implantation participated in the study with patch testing. The study design was retrospective and cross-sectional with no assessment of contact allergy before stenting. Age- and sex-matched patch-tested patients with dermatitis (n = 447) served as controls.

RESULTS

Of Au-stented patients, 54 of 146 (37%) were allergic to gold compared with 85 of 447 (19%) controls (P < 0.001). Within the stented population there were no statistically significant differences in contact allergy to gold or nickel between Ni-stented and Au-stented patients. In multivariate models where other risk factors for contact allergy to gold were considered, the Au stent showed a trend towards statistical significance (odds ratio 1.43, 95% confidence interval 0.95-2.16; P = 0.09).

CONCLUSIONS

As the frequency of contact allergy to gold is higher in stented patients independent of stent type it suggests a previous sensitization. However, several pieces of circumstantial evidence as well as statistical analysis indicate the possibility of sensitization in the coronary vessel by the Au stent. Ni stents and Au stents should not be ruled out as risk factors for induction of contact allergy to these metals.

Patch test results with patients' own perfumes, deodorants and shaving lotions: results of the IVDK 1998-2002

OBJECTIVE

Assessment of the value of patch testing patients' own perfumes, eau de toilette, deodorants and shaving lotions with regard to diagnosing contact allergy to fragrances, and an analysis of the spectrum of concurrent patch test reactions to single fragrance allergens.

STUDY DESIGN

Data of the Information Network of Departments of Dermatology (IVDK; http://www.ivdk.org) regarding patch test results with above products brought in by the patient, considered as possible cause of contact dermatitis, were retrospectively analysed. Between 1998 and 2002, 1468 patients were patch tested with 2557 single products (deodorants, n = 1094; eau de toilette, n = 598; perfume, n = 530; and pre- or after-shave, n = 325; remainder not classifiable), mostly 'as is'.

RESULTS

Positive reactions were observed in 129 patients (to 191 products). In 58 of these patients, no further patch test reactions to the fragrance mix (FM-I), Myroxylon pereirae resin (balsam of Peru) or 4-(4-hydroxy-4-methyl-pentyl)-3-cyclohexencarboxaldehyde (e.g. Lyral(R)) were found. A strong association between contact sensitivity to the above commercial allergens and positive reactions to products was observed. Some single compounds such as ylang-ylang oil, propolis and especially oak moss absolute are important allergens in the 'perfume-positive' subgroup, but less in a subgroup positive to own deodorants.

DISCUSSION

Patch testing this scope of products, brought in by the patient, can be regarded as a simple, safe and effective method to diagnose clinically relevant contact sensitization - the more so, as the composition of such products is ever-changing, and the sensitivity of established 'screening allergens' is thus insufficient.

Unexpected sensitization routes and general frequency of contact allergies in an elderly stented Swedish population

Contact allergy to stent material has been proposed to be a risk factor for restenosis, after percutaneous transluminal coronary angioplasty (PTCA) and stenting. Information on the general frequency of contact allergy in the elderly population is scarce and knowledge of possible sensitization routes is important to investigate. The aim of this study was to investigate contact allergy to stent materials and other allergens. Here we report our findings on the frequency of contact allergies apart from those from stent material. In this retrospective study, we patch tested an elderly population, treated with PTCA and stented, with our standard series. A dermatitis population served as controls. We found a high frequency of contact allergy in both groups but a greater 'contact allergy burden', with generally higher frequencies for contact allergens, in the dermatitis patients as expected. Myroxylon pereirae and caine mix were apart from metals exceptions with statistically significant higher frequencies (P < 0.01) for the stented patients. Contact allergy to nonmetal sensitizers is common in an elderly Swedish stent population although, on the whole, substantially less than in an age and sex-matched dermatitis population. The findings indicate the importance of the oral mucosa for sensitization. In a general population that has been treated with a special medication/treatment procedure, contact allergies not suspected (such as to M. pereirae and to the metals) might suddenly peak. This underlines the importance of a careful evaluation of new products and routines with regard to contact allergies in the population.

Variation in the amount of petrolatum preparation applied at patch testing

The elicitation of a positive patch test reaction in a given individual depends upon the dose of the sensitizer applied, the patch test technique and the occlusion time. The dose is determined by the concentration and volume/amount of test preparation applied. If the same amount/volume of a test preparation is applied all the time with the same test technique (same area of skin) and occlusion time, it is appropriate to use concentration as a dose parameter. Most contact sensitizers are incorporated in petrolatum (pet.). With pet. as vehicle, it is impossible to repeatedly apply an exact volume/amount. This study was performed to investigate the inter- and intra-individual variation of pet. preparation applied at patch testing by 3 technicians. Weighing demonstrated that the 3 technicians had about the same precision in their pet. application. The investigation demonstrates that there is both an inter-individual (statistically significant) and intra-individual variation in the amounts of pet. applied at patch testing for the 3 technicians. Presently, there is no recommendation on what amount of pet. preparation to apply, which merits a decision to be taken based on thorough investigations on the appropriate volumes of pet. preparation to be applied in various patch test systems.

Sensitizations to allergens of TRUE test�in 864 consecutive eczema patients in Israel

The TRUE test is a widespread diagnostic tool for initial patch testing of patients with contact dermatitis (CD). From 2002 to 2005, 864 patients with eczema were patch-tested using TRUE test in one Israeli allergology clinic. 547 (63.3%) patients were female and 317 (36.7%) were male. 346 (40%) patients had > or =1 positive patch test reactions. The most common allergens were nickel sulfate for 114 (13.2%) patients, potassium dichromate 111 (12.8%), fragrance mix 59 (6.8%), cobalt chloride 12 (1.4%), ethylenediamine dihydrochloride 11 (1.3%), epoxy resin 11 (1.3%), balsam of Peru 9 (1.0%), carba mix 7 (0.8%), thiomersal 6 (0.7%), wool alcohol 5 (0.6%), black rubber (PPD) mix 5 (0.6%), neomycin 4 (0.5%); Kathon CG, Colophony and Quaternium 15 - each 2 (0.2%), other allergens - each 1 (0.1%). In male patients, carba mix, black rubber (PPD) mix and epoxy resin sensitivity was more frequent, whereas nickel sulfate, fragrance mix, ethylenediamine dihydrochloride and cobalt chloride sensitivity was significantly more frequent in female patients. Our results are in general agreement with previously published reports, excluding the low sensitivity rates to cobalt, which maybe is missed by TRUE test.

A clinically relevant contact allergy to methyldibromo glutaronitrile at 1% (0.32 mg/cm2) detected by a patch test

Recently, the preservative methyldibromo glutaronitrile (MDBGN) at 0.5% w/w in petrolatum was included in the European standard patch test series based on the studies on chemical stability and consideration of rates of contact allergy, doubtful and irritant reactions as well as information on clinical relevance represented by results of a repeated open application test (ROAT) and patch test concentrations required to diagnose allergic contact dermatitis from MDBGN in individual cases. In this report, a case with a clinically relevant contact allergy to MDBGN, which on the mandatory reading occasion on D3 only was traced by a patch test with MDBGN at 1.0% (0.32 mg/cm2), is presented. The patient suffered from a chronic hand dermatitis, and when the patient stopped using a liquid soap containing MDBGN, the hand dermatitis substantially improved. A ROAT performed in a blinded and controlled way with applications twice daily on the hands with 2 moisturizers with and without MDBGN resulted in a deterioration of the hand dermatitis on the hand to which the MDBGN-preserved moisturizer had been applied.

Clinical update on contact allergy

PURPOSE OF REVIEW

The aim of this article is to review recent findings in contact allergy, regarding clinical research.

RECENT FINDINGS

The biocide methyldibromo glutaronitrile was identified to be an important sensitizer. Subsequently, it was banned from leave-on cosmetics in the European Union. Another group of important allergens that have been studied extensively included the fragrances oak moss absolute, isoeugenol, hydroxyisohexyl 3-cyclohexene carboxaldehyde and farnesol. A new fragrance mix II has been developed for standard testing, which includes the two latter compounds. Dose response studies have demonstrated broad individual variation of elicitation thresholds, dependent on the allergen concentration during induction, and other factors. Some unsuspected routes of exposure to allergens include oral, inhalational, connubial or airborne contact. Experimental studies provide a classification of newly introduced chemicals; increasingly, the local lymph node assay is supplementing and potentially replacing the guinea pig maximization test. Recent advances in occupational contact allergy include, for example, some attempts to improve diagnostics for epoxy resin and other plastic, glue, and cutting fluid components.

SUMMARY

Constant awareness for new allergens, confirmed by critical evaluation, standardization of patch test materials, and the identification of temporal patterns and subgroups at risk will improve both the diagnosis and prevention of allergic contact dermatitis.

The European standard series in 9 European countries, 2002/2003 - First results of the European Surveillance System on Contact Allergies

Since January 2001, the European Surveillance System on Contact Allergies (ESSCA), supported by European Union funding (contract QLK4-CT-2001-00343), has started to collect patch-test data. This comprises a standardized clinical history and the patch-test results using the European standard series, from 17 centres in 9 European countries listed above. In 2002 and 2003, 10 511 patients' test results have been pooled and analysed. The anamnestic data partly reflect the subspecialties of some centres. The most common allergen was nickel sulfate (17.3%); however, large international variations were observed. The prevalence of contact allergy to Myroxylon pereirae resin (balsam of Peru) (5.8%) is coming close to the frequency found with the fragrance mix (6.4%). Regarding contact allergy to chromium compounds, different frequencies were noted in the 2 centres focused on occupational dermatitis (2.3% in the FIOH versus 7.4% in the Nofer Institute). These most likely reflect the beneficial effect of addition of ferrous sulfate in one, but not the other country. As differences may partly be due to different patch-test reading, standardization may need to be refined further. By providing post-marketing surveillance in the field of contact allergy, ESSCA will meet its objective of increased consumer safety across Europe.

Preservatives in registered chemical products

Preservatives are common causes of contact allergy and contact dermatitis. Exposure to cosmetics, personal care products, consumer products and occupationally used products often involve contact with the same range of preservatives. The aim of this study is to provide an overview on the occurrence of preservatives in registered chemical products. The studied preservatives included substances from standard patch test series and other preservatives relevant for registered chemical products. Data obtained from the Danish Product Register Database (PROBAS) in January 2005 were compared to similar data from January 2002. Paints/lacquers, cleaning agents and printing inks were the most frequently registered product categories, and the studied preservatives were registered in most of the product categories included in the study. For most product categories the total number of registered products was stable during the study period. Butylated hydroxytoluene, benzoic acid, isothiazolinones, Bronopol and formaldehyde showed an increase from 2002 to 2005. Most of these changes occurred in the product category paints/lacquers, for which a doubling mainly due to a change in registration practice was observed. The frequent registration of isothiazolinones (MCI/MI and benzisothiazolinone) in paints/lacquers may be a possible explanation for the relative high and stable frequency of positive patch test reactions to MCI/MI.