S3 Guidelines: Epicutaneous patch testing with contact allergens and drugs - Short version, Part 2

Global Guidelines in Dermatology Mapping Project (GUIDEMAP)-A systematic review of the methodological quality of contact dermatitis clinical practice guidelines

The Global Guidelines in Dermatology Mapping Project (GUIDEMAP) assesses the methodological quality of clinical practice guidelines (CPGs) for high-burden skin diseases. This review focuses on contact dermatitis. We searched MEDLINE, Embase, PubMed, Web of Science, Cochrane Library, Emcare, Epistemonikos, PsycINFO and Academic Search Premier for CPGs published between 1 November 2018 and 1 November 2023. Prespecified guideline resources were hand searched. Two authors independently undertook screening, data extraction and quality assessments. Instruments used were the Appraisal of Guidelines for Research and Evaluation (AGREE) II Reporting Checklist, the U.S. Institute of Medicine's (IOM) criteria of trustworthiness, The Agency for Healthcare Research and Quality's National Guideline Clearinghouse Extent Adherence to Trustworthy Standards (NEATS) Instrument and Lenzer's Red Flags. Twenty five CPGs were included, exhibiting heterogeneity in both the topics they addressed and their methodological quality. Whereas the CPGs on management of hand eczema from Denmark, Europe and the Netherlands scored best, most CPGs fell short of being clear, unbiased, trustworthy and evidence-based. Disclosure of conflicts of interest scored well, and areas needing improvement include 'strength and wording of recommendations', 'applicability', 'updating' and 'external review'. Adhering to AGREE II and Grading of Recommendations, Assessment, Development and Evaluations (GRADE) enhances methodological quality.

Associations between tobacco smoking status and patch test results-A cross-sectional pilot study from the Information Network of Departments of Dermatology (IVDK)

BACKGROUND

Earlier studies suggested a potential association between tobacco smoking and nickel sensitization, but little is known about other contact allergens.

OBJECTIVES

To investigate the association of smoking status and contact sensitizations as well as subtypes of dermatitis, and to analyse the sensitization profiles of tobacco smokers.

PATIENTS AND METHODS

Within the Information Network of Departments of Dermatology (IVDK), we performed a cross-sectional multicentre pilot study comprising 1091 patch-tested patients from 9 departments, comparing 541 patients with a history of cigarette smoking (281 current and 260 former smokers) with 550 never-smokers.

RESULTS

We could not confirm the previously reported association between nickel sensitization and tobacco smoking. Moreover, sensitizations to other allergens, including colophony, fragrance mix I, Myroxylon pereirae and formaldehyde, were not increased in cigarette smokers compared with never smokers. Hand dermatitis (50.6% vs. 33.6%) and occupational cause (36.2% vs. 22.5%) were significantly more frequent among cigarette smokers compared with never-smokers as shown by non-overlapping 95% confidence intervals.

CONCLUSIONS

Although our study does not allow a firm conclusion on whether smoking status contributes to certain contact sensitizations, it confirms an association of smoking with hand dermatitis and occupational cause.

Declining frequency of sensitization to fragrance mixes I and II: IVDK-data of the years 2012-2021

BACKGROUND

EU Commission Regulation 2017/1410 prohibits using atranol and chloroatranol, the main allergens in Evernia prunastri (oakmoss), and hydroxyisohexyl 3-cyclohexene carboxaldehyde (HICC) in cosmetic products. Oakmoss absolute is contained in fragrance mix (FM) I and HICC in FM II which are patch tested as screening mixtures in the baseline series.

OBJECTIVE

To describe the time trends of reaction frequencies to both FMs as well as to their components in FM-positive patients.

METHODS

Retrospective analysis of data from the Information Network of Departments of Dermatology (IVDK), 2012-2021.

RESULTS

Positive reactions to FM I (FM II) declined from 9.1% (4.7%) in 2012 to 4.6% (3.0%) in 2021. Full breakdown tests were performed in 24% (FM I) and 31% (FM II), respectively, of the mix-positive patients. From this data, frequencies of sensitization to the 14 single fragrances of FM I and FM II were calculated. For the majority, a decline was noted from 2012/2013 to 2020/2021, for oakmoss absolute 1.9%-0.8% and for HICC 1.8%-0.9%.

CONCLUSION

EU Commission Regulation 2017/1410 was an effective measure. However, our data have some limitations, possibly causing underestimation of sensitization frequencies to fragrances.

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.

Ganciclovir-induced drug reaction with eosinophilia and systemic symptoms

Drug reaction with eosinophilia and systemic symptoms (DRESS) is a severe cutaneous adverse reaction involving multiorgan failure, with a complex interaction of various drugs, human herpesvirus reactivation and immune abnormalities suggested as the aetiology. We herein present the case of a 70-year-old man with a one-week history of fever, facial oedema, erythematous macules and purpura on his trunk and extremities. He had anti-TIF1γ antibody-positive dermatomyositis and was treated with prednisolone sodium succinate (20 mg/day). Three weeks earlier, he was treated with ganciclovir (250 mg/day) for 7 days to treat asymptomatic cytomegalovirus viraemia. Laboratory investigations revealed eosinophilia with atypical lymphocytes and elevated liver enzyme levels. A histological examination showed interface dermatitis with necrotic keratinocytes, perivascular infiltration of lymphocytes and eosinophils in the upper dermis and erythrocyte extravasation without vasculitis. A lymphocyte transformation test (LTT) was positive for ganciclovir (stimulation index: 260%; normal: <180%). We diagnosed DRESS caused by ganciclovir on the basis of clinical findings and course (Definite; RegiSCAR score: 7). He was treated with prednisolone sodium succinate (40 mg/day) and topical clobetasol propionate (0.05%) ointment twice daily. After the initiation of treatment, the skin lesions and laboratory abnormalities gradually improved. To our knowledge, this is the first case of DRESS caused by ganciclovir. The patients in whom ganciclovir is used are often immunosuppressed and may be overlooked as the causative drug for DRESS by conventional skin tests. We considered that LTT is useful for identifying causative drugs of DRESS, especially in immunosuppressed patients, such as the present case.

S2k-Leitlinie Diagnostik, Prävention und Therapie des Handekzems: S2k guideline diagnosis, prevention and therapy of hand eczema

Die S2k‐Leitlinie „Diagnostik, Prävention und Therapie des Handekzems (HE)“ gibt auf der Grundlage eines evidenz‐ und konsensbasierten Ansatzes konkrete Handlungsanweisungen und Empfehlungen für die Diagnostik, Prävention und Therapie des HE. Die Leitlinie wurde auf der Grundlage der deutschen Leitlinie „Management von Handekzemen“ aus dem Jahr 2009 und der aktuellen Leitlinie der European Society of Contact Dermatitis (ESCD) „Guidelines for diagnosis, prevention and treatment of hand eczema“ aus dem Jahr 2022 erstellt. Allgemeines Ziel der Leitlinie ist es, Dermatologen und Allergologen in der Praxis und Klinik eine akzeptierte, evidenzbasierte Entscheidungshilfe für die Auswahl sowie Durchführung einer geeigneten und suffizienten Therapie für Patienten mit Handekzemen zur Verfügung zu stellen. Die Leitlinie basiert auf zwei Cochrane‐Reviews zu therapeutischen und präventiven Interventionen beim HE. Die übrigen Kapitel wurden überwiegend basierend auf nicht systematischen Literaturrecherchen durch die Expertengruppe erarbeitet und konsentiert. Die Expertenkommission bestand aus Mitgliedern von allergologischen und berufsdermatologischen Fachgesellschaften und Arbeitsgruppen, einer Patientenvertretung und Methodikern. Im Rahmen einer Konsensuskonferenz am 15.09.2022 wurden die Vorschläge für die Empfehlungen und Kernaussagen unter Verwendung eines nominalen Gruppenprozesses konsentiert. Der strukturierte Konsensfindungsprozess wurde professionell moderiert. Die vorliegende Leitlinie hat eine Gültigkeit bis zum 22.02.2028.

S2k guideline diagnosis, prevention, and therapy of hand eczema

The consensus-based guideline "Diagnosis, prevention, and treatment of hand eczema (HE)" provides concrete instructions and recommendations for diagnosis, prevention, and therapy of HE based on an evidence- and consensus-based approach. The guideline was created based on the German guideline "Management von Handekzemen" from 2009 and the current guideline of the European Society of Contact Dermatitis (ESCD) "Guidelines for diagnosis, prevention, and treatment of hand eczema" from 2022. The general goal of the guideline is to provide dermatologists and allergologists in practice and clinics with an accepted, evidence-based decision-making tool for selecting and conducting suitable and sufficient therapy for patients with hand eczema. The guideline is based on two Cochrane reviews of therapeutic and preventive interventions for HE. The remaining chapters were mainly developed and consented based on non-systematic literature research by the expert group. The expert group consisted of members of allergological and occupational dermatological professional associations and working groups, a patient representative, and methodologists. The proposals for recommendations and key statements were consented by using a nominal group process during a consensus conference on September 15, 2022. The structured consensus-building process was professionally moderated. This guideline is valid until February 22, 2028.

Contact allergy to ingredients of hair cosmetics in female hairdressers and female consumers-An update based on IVDK data 2013-2020

BACKGROUND

Hair cosmetic products contain several, partly potent contact allergens, including excipients like preservatives. Hand dermatitis in hairdressers is common, scalp and face dermatitis in clients or self-users (summarised here as 'consumers') may be severe.

OBJECTIVE

To compare frequencies of sensitization to hair cosmetic ingredients and other selected allergens between female patch tested patients working as hairdressers and consumers without professional background, respectively, who were tested for suspected allergic contact dermatitis to such products.

METHODS

Patch test and clinical data collected by the IVDK (https://www.ivdk.org) between 01/2013 and 12/2020 were descriptively analysed, focusing on age-adjusted sensitization prevalences in the two subgroups.

RESULTS

Amongst the 920 hairdressers (median age: 28 years, 84% hand dermatitis) and 2321 consumers (median age: 49 years, 71.8% head/face dermatitis), sensitization to p-phenylenediamine (age-standardised prevalence: 19.7% and 31.6%, respectively) and toluene-2,5-diamine (20 and 30.8%) were most common. Contact allergy to other oxidative hair dye ingredients was also more commonly diagnosed in consumers, whereas ammonium persulphate (14.4% vs. 2.3%) and glyceryl thioglycolate (3.9 vs. 1.2%) as well as most notably methylisothiazolinone (10.5% vs. 3.1%) were more frequent allergens in hairdressers.

CONCLUSIONS

Hair dyes were the most frequent sensitizers both in hairdressers and in consumers; however, as indication for patch testing may differ, prevalences cannot directly be compared. The importance of hair dye allergy is evident, often with marked coupled reactivity. Workplace and product safety need to be further improved.

Patch testing hydroperoxides of limonene and linalool in consecutive patients-Results of the IVDK 2018-2020

BACKGROUND

Hydroperoxides of limonene (Lim-OOHs) and linalool (Lin-OOHs) are potent contact sensitizers.

OBJECTIVES

To investigate the prevalence of positive patch test (PT) reactions to Lim-OOHs and Lin-OOHs in consecutive patients, their demographic factors and concomitant reactions.

METHODS

Between 7/2018 and 12/2020, Lim-OOHs 0.3% pet. and Lin-OOHs 1% pet. were patch tested in 5511 consecutive patients. We assessed PT reactivity and analysed data from patients with either positive or negative PTs to Lim-OOHs and Lin-OOHs.

RESULTS

Positive PT results to Lim-OOHs (n = 170, 3.1%) and Lin-OOHs (n = 483, 8.8%) were frequent. Most of the positive reactions were weak (LimOOHs n = 134/LinOOHs n = 429), and even more frequently, doubtful (n = 252/n = 578) or irritant reactions (n = 81/n = 178) were documented. PT reactivity to Lim-OOHs and Lin-OOHs was increased in patients with irritant reactions to sodium lauryl sulphate (SLS). The proportion of leg dermatitis and concomitant positive reactions to fragrances and essential oils was increased in patients with reactivity to these hydroperoxides.

CONCLUSION

The observed reaction pattern suggests that both test preparations display an irritant potential with an increased risk of false positive reactions. Preparations should be chemically monitored in order to reduce irritancy. Mindful interpretation of PT results and aimed patch testing of lower concentrations is recommended.

Contact sensitization to benzisothiazolinone: IVDK-data of the years 2002 to 2021

BACKGROUND

Benzisothiazolinone (BIT; CAS no. 2634-33-5) is used as a biocide in various products, including water-based paints, metalworking fluids, and household products. In recent years, increasing sensitization rates have been observed in Europe.

OBJECTIVE

To describe a time trend of sensitization to BIT, analyse concomitant reactions, and identify patients with increased risk of BIT sensitization.

METHODS

Retrospective analysis of data from 26 739 patients patch tested with BIT, sodium salt, 0.1% petrolatum as part of several special test series within the Information Network of Departments of Dermatology (IVDK), 2002 to 2021.

RESULTS

Positive reactions to BIT were noted in 771 patients (2.9%). Sensitization frequency varied over time and increased in recent years, peaking at 6.5% in 2020. Painters and metalworkers handling metalworking fluids, but not cleaners, had a significantly increased risk of BIT sensitization. From our data, there is no evidence of immunological cross-reactivity between BIT and other isothiazolinones.

CONCLUSION

The increasing frequency of sensitization justifies adding BIT to the baseline series. More research on the clinical relevance of positive patch test reactions to BIT and the cause for the rising numbers of BIT sensitization is needed.

HIGHLIGHTS

Frequency of sensitization to BIT has increased in recent years. The increasing frequency of sensitization justifies adding BIT to the baseline series. Painters and metalworkers handling metalworking fluids, but not cleaners, has a significantly increased risk of BIT sensitization. We found no evidence of immunological cross-reactivity between BIT and other isothiazolinones.

Allergic Contact Cell-Mediated Hypersensitivity in Psoriasis: A Narrative Minireview

The dysfunctionality of the protective skin barrier in psoriasis allows easier cutaneous penetration of various contact haptens; thus, such patients can develop allergic contact hypersensitivity as a comorbidity. Both skin conditions involve T-cell-mediated mechanisms. Dermatologists and allergists should consider assessing allergic contact cell-mediated hypersensitivity in selected psoriasis patients, especially those with palmoplantar psoriasis and who are refractory to topical treatments, and in patients with psoriasis, with or without arthritis, treated with biologics that present skin lesions clinically suggestive of contact dermatitis.

The benefit of late readings in patch testing depends both on allergen and patient characteristics

BACKGROUND

Patch test (PT) readings are recommended after 48 h and 72 h (D3). An additional day 7 (D7) reading has been suggested by some, although data on efficient patient selection are scarce. We investigated positive D7 reactions regarding (i) allergens in the baseline series and additional PT series of the German Contact Dermatitis Research Group (DKG) and (ii) characteristics of the patients tested.

METHODS

Retrospective, multicentre analysis of 190 allergens derived from 17 DKG test series in 4687 patients with an additional D7 reading. Patients were patch tested with the baseline series and additional series, if required. Occurrence of novel D7 reactions as well as increasing skin reactions from D3 to D7 was analysed separately.

RESULTS

Depending on the allergen tested, waiving D7 readings would have missed 4.4-26.8% of positive PT results. Patch test series with the highest number of novel D7 reactions were baseline series, metal series, and leather/shoe series. New positive reactions on D7 were associated with age over 50 years and with a negative irritant control containing sodium lauryl sulphate. Of note, application of the PT allergens for 48 h instead of 24 h was positively associated with late PT reactions.

CONCLUSION

Within the most frequently tested allergens, without late readings, on average 11.7% of sensitizations would have been missed. Novel late reacting allergens were identified. This study comprehensively dissects patient-, allergen- and test-dependent parameters in support for D7 readings. We propose to always consider late readings individually based on effort-benefit considerations.

Contact sensitization to essential oils: IVDK-data of the years 2010 - 2019

BACKGROUND

Essential oils (EOs) are widely used in cosmetics, perfumes, massage fluids, aroma therapy, and natural medicine. Some essential oils contain contact sensitizers.

OBJECTIVES

To describe the frequency of sensitization to EOs in dermatitis patients presenting in skin clinics including concomitant reactions, to evaluate the EO patch test preparations, and to identify patient groups with an increased risk of EO sensitization.

PATIENTS AND METHODS

Retrospective analysis of data from the Information Network of Departments of Dermatology (IVDK), 2010-2019.

RESULTS

Twelve EOs were patch tested in an aimed manner in 10 930 patients, of whom 908 (8.3%) reacted to at least one EO. Only 6 EOs elicited more than 1% positive patch test reactions: ylang ylang (I + II) oil (3.9%), lemongrass oil (2.6%), jasmine absolute (1.8%), sandalwood oil (1.8%), clove oil (1.6%), and neroli oil (1.1%). Concomitant reactions among EOs or to EOs and fragrances were frequent. Among EO-positive patients, women, leg dermatitis patients, patients aged 40 years or more, masseurs and cosmeticians were over-represented.

CONCLUSIONS

Sensitization to EOs occurs, albeit infrequently in most cases. Masseurs and cosmeticians have an increased risk of sensitization to EOs. This article is protected by copyright. All rights reserved.

Methotrexate and Patch Testing: A Retrospective Review

BACKGROUND

Patch testing while taking systemic immunosuppressants is sometimes unavoidable. Methotrexate (MTX) is the immunosuppressant currently considered least likely to negatively impact patch testing.

OBJECTIVE

The aim of the study was to characterize a cohort of patients patch tested while taking MTX.

METHODS

This is a retrospective review of patients patch tested at the University of North Carolina Dermatology in Chapel Hill, North Carolina, from 2010 to 2019, comparing patch test results of patients taking MTX with those of a control group.

RESULTS

An overall 52.8% positivity rate (356/674) was observed. Sixty two of 674 patients were patch tested while taking MTX, with a 46.8% positivity rate (29/62) compared with 53.4% (327/612) in the control group. The control group experienced 975 reactions, including 637 1+ reactions, 291 2+ reactions, and 47 3+ reactions. The MTX group experienced 50 reactions, including thirty-two 1+ reactions, fourteen 2+ reactions, and four 3+ reactions. The difference between the distributions was not statistically significant. Mean weekly MTX dose was 15.6 mg, whereas mean total accumulated dose was 251.6 mg. There was no statistically significant difference between weekly dose and total accumulated dose in patients with positive or negative results.

CONCLUSIONS

In our cohort, MTX had no discernible effect on patch test results, supporting use during patch testing with minimal false-negative risk.

Is benzyl alcohol a significant contact sensitizer?

BACKGROUND

Benzyl alcohol is a widely used preservative, solvent, and fragrance material. According to published data, it is a rare sensitizer in humans.

OBJECTIVES

To identify characteristics and sensitization patterns of patients with positive patch test reactions to benzyl alcohol and to check the reliability of the patch test preparation benzyl alcohol 1% pet.

PATIENTS AND METHODS

Retrospective analysis of data from the Information Network of Departments of Dermatology (IVDK), 2010-2019.

RESULTS

Of 70,867 patients patch tested with benzyl alcohol 1% pet., 146 (0.21%) showed a positive reaction, most of them (89%) only weak positive. The number of doubtful and irritant reactions significantly exceeded the number of positive reactions. Reproducibility of positive test reactions was low. Among benzyl alcohol-positive patients, compared to benzyl alcohol negative patients, there were significantly more patients with leg dermatitis (17.8% vs. 8.6%), more patients aged 40 years or more (81.5% vs. 70.5%), and more patients who were tested because of a suspected intolerance reaction to topical medications (34.9% vs. 16.6%). Concomitant positive reactions were mainly seen to fragrances, preservatives, and ointment bases.

CONCLUSIONS

Sensitization to benzyl alcohol occurs very rarely, mainly in patients with stasis dermatitis. In view of our results, benzyl alcohol cannot be regarded as a significant contact allergen, and therefore marking it as skin sensitizer 1B and labelling it with H 317 is not helpful.

Patch Testing in Drug Eruptions: Practical Aspects and Literature Review of Eruptions and Culprit Drugs

ABSTRACT

There is overwhelming evidence that many delayed cutaneous adverse drug reactions (beginning >6 hours after drug intake) are mediated by delayed-type (type IV) hypersensitivity, including maculopapular eruptions, erythroderma, symmetrical drug-related intertriginous and flexural exanthema/baboon syndrome, eczematous eruptions, fixed drug eruptions, acute generalized exanthematous pustulosis, and drug reaction with eosinophilia and systemic symptoms/drug-induced hypersensitivity syndrome. Therefore, after resolution of the reaction, patch tests should be performed as first diagnostic method to identify the culprit drug(s). This article provides tools to perform drug patch tests properly and safely, discussing clinical history, indications, procedure, drug patch test materials, sensitivity, the meaning of negative patch tests, and safety of the procedure. In addition, a literature review of eruptions and culprit drugs is provided in tabular format.

Epicutaneous Patch Testing in Type IV Allergy Diagnostics: State of the Art and Best Practice Recommendations

This chapter summarises all relevant aspects of patch testing, closely following recommendations outlined in a recent European, and a German S3 guideline on diagnostic patch testing with contact allergens and medicinal products (drugs). Patch testing is indicated in patients suspected of suffering, or having been suffering, from delayed-type hypersensitivity leading to allergic contact dermatitis or other skin and mucosal diseases. Sections of this chapter include detailed indications, reasons for possibly postponing the test, considerations on choosing haptens (contact allergens) to test, various aspects of the application of patch test allergen preparations (storage, dosing) and of testing with individual materials provided by the patients. Special aspects of patch testing in cutaneous adverse drug reactions, children, or occupational contact dermatitis are outlined. Supplemental test methods, notably the repeated open application test, are briefly described. Finally, the final evaluation in terms of assessment of clinical relevance of reactions and patient counselling are outlined.

Modern diabetes devices for continuous blood sugar measuring: Limitations due to contact allergies

During the past years, diabetes diseases have increased significantly worldwide. However, new technologies such as continuous glucose measurement using a subcutaneous sensor are developing just as rapidly. A continuous improvement in insulin pump therapy is also contributing to an improved quality of life. A common feature of these modern devices for diabetes therapy is that they remain fixed in place on the skin for several days. In recent years, skin reactions, in particular pronounced contact dermatitis due to the devices and their adhesives have been increasingly reported. In particular, isobornyl acrylate, which used to be included in a glucose measurement sensor set, was identified as a main allergen. Development of contact allergy can result both in a necessity to quit the measuring system and in allergic cross-reactions to other systems.

Patch test informed consent form: position statement by European Academy of Dermatology and Venereology Task Force on Contact Dermatitis

BACKGROUND

To our knowledge, an international consensus is lacking regarding the development of an adequate informed consent form for a patch test (PT) and the information that should be included in such document.

OBJECTIVES

The aim of the study was to reach a consensus on the specific points that need to be addressed in a PT consent form.

METHODS

A Delphi survey, comprising 2 rounds and 1 final discussion, was used to gather and analyse data, which was conducted over the Internet. Each statement that reached a consensus with the respondents (9 expert dermatologists from Europe) was defined as a median consensus score (MED) of ≥7 and agreement among panelists as an interquartile range (IQR) of ≤3. All study participants were members of the EADV task force on contact dermatitis.

RESULTS

The expert panel addressed several topics that should be included in an informed consent form for a PT: introduction, preparation for PT, testing procedure, allowed activities, adverse events and additional authorizations.

CONCLUSIONS

Our results assess recommendations regarding points to be contained in an informed consent form for a PR. Future actions towards standardization and harmonization of this specific consent form are needed.

Occupational contact dermatitis in painters and varnishers: Data from the Information Network of Departments of Dermatology (IVDK), 2000 to 2019

INTRODUCTION

Painters and varnishers ("painters") are exposed to various contact allergens and skin irritants, and therefore, are at risk for developing occupational dermatitis (OD).

OBJECTIVE

To describe the spectrum of occupational sensitizations in painters and revise the corresponding current patch test recommendations.

PATIENTS AND METHODS

Retrospective analysis of Information Network of Departments of Dermatology (IVDK) data from 2000 to 2019 with focus on male painters with OD, ages 20-59 years (n = 557) in comparison to age-matched male painters without OD (n = 422) and male OD patients who have had never worked as painters (n = 13 862).

RESULTS

Male painters with OD have a significantly higher rate of allergic contact dermatitis and face dermatitis than male patients with OD who work in other professions. Positive patch tests to epoxy resin, methylisothiazolinone (MI), and methylchloroisothiazolinone (MCI)/MI were significantly more frequent in painters with OD than in the other groups. Epoxy resin sensitization was significantly associated with face dermatitis.

CONCLUSIONS

Epoxy resin, MI, and MCI/MI represent the most important occupational sensitizers in painters. In addition to baseline, resins and glues, and industrial biocides series, the patients' own workplace materials should be tested in painters with suspected OD.

Masks use and facial dermatitis during COVID-19 outbreak: is there a difference between CE and non-CE approved masks? Multi-center, real-life data from a large Italian cohort

BACKGROUND

During the recent COVID-19 outbreak, masks became mandatory and shortages frequent, therefore the prevalence of non-CE (European Conformity Mark) approved masks increased in the general population. We aimed to quantify the prevalence of mask-related cutaneous side effects and the differences between CE and non-CE approved masks.

METHODS

In this multicenter prospective observational study conducted from March 20, 2020 to May 12, 2020(during and after quarantine), patients attending emergency departments for a dermatological consult were clinically assessed and their masks were inspected to detect CE marks and UNI (Italian National Unification Entity) norms. Patients with history of facial dermatoses or under current treatment for facial dermatoses were excluded.

RESULTS

We enrolled 412 patients (318 during quarantine and 94 after quarantine). CE-approved masks were observed 52.8% vs. 24.5%, whilst subsets of non-CE approved masks were 9.7% vs. 14.9% (Personal protective equipment (PPE)-masks), 16.4% vs. 12.8% (surgical masks [SM]), and 21.1% vs. 47.9%(non-PPE) and (non-SM masks), respectively during and after quarantine. Remarkably, non-CE-approved masks resulted in patients displaying a statistically significant higher incidence of facial dermatoses and irritant contact dermatitis compared to CE-approved masks, and these differences were mainly driven by non-PPE non-SM masks. Comparing quarantine and after quarantine periods, no statistically significant differences were found for CE-approved masks, whilst differences were detected in non-CE-approved masks regarding incidence of facial dermatoses (P<0.0001)and irritant contact dermatitis (P=0.0041).

CONCLUSIONS

Masks are essential to prevent COVID-19 but at the same time higher awareness regarding mask specifications should be promoted in the general population. Non-PPE and non-SM masks should undergo more rigorous testing to prevent the occurrence of cutaneous side effects and future patients' lawsuit damages.

Contact sensitizations to disinfectants containing alcohols or quaternary ammonium compounds are rarely of clinical relevance

BACKGROUND

The use of disinfectants is part of the everyday life of people, especially in the medical profession. During the coronavirus disease 2019 (COVID-19) pandemic, the use of disinfectants continues to increase and is of fundamental importance in infection control.

OBJECTIVES

To determine the frequency of sensitization and the value of patch testing to didecyldimethylammonium chloride (DDAC) and the alcohols ethanol, 1-propanol, and isopropanol.

METHODS

Clinical patch test data of 145 patients with suspected contact allergy to disinfectants were retrospective analysed.

RESULTS

Among the 145 patients patch tested with the different alcohols, only one nurse was detected with a possible allergy to 1-propanol. Additional patch testing in 84 patients with DDAC 0.05% resulted in five patients with weakly positive reactions only, without clinical relevance. Patch testing with DDAC 0.03% showed no positive reactions at all on day 3 readings.

CONCLUSIONS

DDAC and alcohols are rarely responsible for allergic contact dermatitis. The accused products of the patients should be checked for other allergens and further additives with skin-irritating properties. Individual susceptibility and mishandling of the disinfectants should be considered.

A negative breakdown test in a fragrance mix I-positive patient does not rule out contact allergy to its fragrance constituents

BACKGROUND

In about half of the patients reacting positive to fragrance mix I (FM I), breakdown testing remains negative. This raises the question of whether the reaction to FM I is false-positive, or the breakdown test is false-negative.

OBJECTIVES

To identify characteristics and sensitization patterns of patients positive to FM I, but not to its fragrance constituents.

PATIENTS AND METHODS

Retrospective analysis of data from the Information Network of Departments of Dermatology (IVDK) between 2005 and 2019. Three patient groups were defined according to their reaction pattern: Group I, FM I positive and ≥1 single fragrance positive in the breakdown test (n = 1912); Group II, FM I positive and breakdown test negative (n = 1318); Group III, FM I negative (n = 19 790).

RESULTS

Regarding the pattern of concomitant reactions to other fragrances, Group II had an intermediate position between Group I and Group III. In other respects (age and sex distribution, frequency of sensitization to non-fragrance baseline series allergens), Group II rather resembled Group I.

CONCLUSIONS

Not every positive reaction to FM I in patients with negative breakdown tests is false-positive. There may be false-negative reactions to the single fragrance components when patch tested at 1% pet. Raising patch concentrations of some single fragrances is recommended.

Improving povidone-iodine and iodine preparations for patch testing

BACKGROUND

Allergy evaluation by patch testing with povidone-iodine (PVP-I) or iodine remains challenging, because current patch test preparations frequently lead to false-positive or irritant skin reactions.

OBJECTIVES

To investigate different preparations for iodine patch tests and to assess their clinical relevance with repeated open application tests (ROATs).

METHODS

We monocentrically analyzed 95 patients with suspected allergy to disinfectants in retrospect who underwent parallel iodine patch testing with four preparations: PVP-I 2% aq., 5% aq., 10% aq., and iodine 0.5% pet.

RESULTS

In 27 of 95 patients (28.4%), we found positive reactions to one of the four test preparations. After ROATs in 22 of these 27 positively tested individuals, only one patient was diagnosed with iodine allergy. In contrast, 31 of 95 patients (32.6%) showed irritant or questionable patch test reactions on day 2 (D2) and/or D3 and/or D7 to one or more test preparations. Testing with PVP-I 2% aq. resulted in the lowest number of doubtful skin reactions while detecting the single allergic patient.

CONCLUSION

PVP-I 2% aq. was found to be the optimal patch test preparation. In general, iodine allergy appears to be substantially overestimated, and positive patch test responses to iodine should prompt an urgent ROAT for confirmation before diagnosing iodine allergy.

Optical coherence tomography for patch test grading: A prospective study on its use for noninvasive diagnosis of allergic contact dermatitis

BACKGROUND

The diagnosis of allergic contact dermatitis should be confirmed by skin patch tests. Distinguishing between irritant and allergic reactions is sometimes difficult.

OBJECTIVES

To analyse the in vivo morphological changes in patch test reactions compared to healthy skin, and to detect subclinical changes in doubtful reactions using optical coherence tomography (OCT). To develop an OCT-based algorithm to support patch-test grading.

METHODS

One hundred twenty-nine skin patch-test areas were scanned with OCT to evaluate the following features: architectural and vascular morphology, epidermal thickness, optical attenuation coefficient (AC), and blood flow at 0.1, 0.2, and 0.35 mm depth.

RESULTS

Most common OCT features of acute contact allergic reactions in patch tests were spongiosis with microvesicles (94.8%), macrovesicles (60.3%), and coalescing vesicles (46.6%), the latter useful in differentiating acute allergic from irritant dermatitis (P-value < .05). Objective quantitative parameters correlated well with the severity grade: epidermal thickness due to spongiosis, AC (P-value < .05) and blood flow at 0.2 and 0.35 mm (P-value < .01).

CONCLUSIONS

OCT as a noninvasive diagnostic tool, established for skin cancer diagnosis, is useful for evaluating contact allergic patch-test reactions. Not only morphological but also objective features such as blood flow and AC correlate with the reaction severity. Further studies are needed to explore the differences in irritant and allergic contact dermatitis.