Thin-layer Rapid Use Epicutaneous Research Articles

Analysis of patch testing results in patients with contact dermatitis in Istanbul, Turkey, from 2012 to 2022.

Allergens responsible for allergic contact dermatitis (ACD) differ between populations. They can even change over the years with the effect of environmental factors. To evaluate the results of patch testing performed in our center. In this study, the thin-layer rapid-use epicutaneous (T.R.U.E.) test results of patients with a diagnosis of ACD between 2012 and 2022 were retrospectively evaluated. In 431 (42.5%) of the total 1012 patients, a positive reaction to at least one allergen was detected in the patch test. Allergen positivity was most detected for nickel sulphate (16.8%), gold sodium thiosulfate (GST) (6.9%), thimerosal (4.2%), fragrance mix (3.4%), carba mix (3.2%), and cobalt dichloride (2.9%). Nickel sulfate and GST sensitivity was found to be significantly higher in women, fragrance mix sensitivity in men, thimerosal sensitivity in individuals aged under 40 years, colophony and balsam of Peru sensitivity in head and neck dermatitis, and carba mix and thiuram mix sensitivity in atopic individuals. This study presents comprehensive data from Turkey concerning the sensitivity frequencies for allergens included in the T.R.U.E. test.

Patch testing with the Japanese baseline series 2015: A 4-year experience.

The Japanese baseline series (JBS), established in 1994, was updated in 2008 and 2015. The JBS 2015 is a modification of the thin-layer rapid-use epicutaneous (TRUE) test (SmartPractice Denmark, Hillerød, Denmark). No nationwide studies concerning the TRUE test have previously been reported. To determine the prevalence of sensitizations to JBS 2015 allergens from 2015 to 2018. We investigated JBS 2015 patch test results using the web-registered Skin Safety Care Information Network (SSCI-Net) from April 2015 to March 2019. Patch test results of 5865 patients were registered from 63 facilities. The five allergens with the highest positivity rates were gold sodium thiosulfate (GST; 25.7%), nickel sulfate (24.5%), urushiol (9.1%), p-phenylenediamine (PPD; 8.9%), and cobalt chloride (8.4%). The five allergens with the lowest positivity rates were mercaptobenzothiazole (0.8%), formaldehyde (0.9%), paraben mix (1.1%), mercapto mix (1.1%), and PPD black rubber mix (1.4%). Nickel sulfate and GST had the highest positivity rates. The JBS 2015, including a modified TRUE test, is suitable for baseline series patch testing.

Contact allergy to hydroperoxides of limonene and linalool in a pediatric population

Contact allergy to hydroperoxides of limonene and linalool in a pediatric population

Patch Test Results of Contact Sensitization in Children Without Atopic Dermatitis: A Single Tertiary Center Experience.

Allergic contact dermatitis (ACD) has become more frequent in children. The prevalence of contact sensitization varies with respect to age, sex, and geographic localization. The aim of the study was to investigate the experience of a tertiary health center regarding the patch test results of contact sensitization in children without atopic dermatitis. This is a retrospective review of 89 children (30 boys and 59 girls) who were aged between 3 and 18 years and who were diagnosed with ACD between July 2013 and July 2017. Children with a known history of atopic dermatitis were excluded. All patients were tested with the TRUE (Thin-layer Rapid Use Epicutaneous) test series. The most frequently determined allergens by TRUE test were methylchloroisothiazolinone (n = 7 [16.3%]), disperse blue 106 (n = 5 [11.6%]), and bacitracin (n = 5 [11.6%]). Formaldehyde-related allergens produced 15 positives. Preservatives, such as methylchloroisothiazolinone, formaldehyde, and formaldehyde releasers, emerge as the most frequent allergens in children who undergo patch testing because of ACD. This finding might be attributed to the increase in the utilization of these chemical compounds in personal hygiene products for children.

Expanded Series and Personalized Patch Tests for Children: A Retrospective Cohort Study

Epicutaneous patch testing was developed as a simple and effective method for diagnosing allergic contact dermatitis (ACD). Despite its proven value in ACD diagnoses, there is no defined standard for patch testing in children. The aims of this study were to assess patch test positivity in pediatric patients with and without a history of atopic dermatitis suspected to have ACD, to compare these results with what the Thin-Layer Rapid Use Epicutaneous (T.R.U.E.) Test would have captured, and to evaluate likely exposures. Pediatric patients receiving a North American 80 Comprehensive Series patch test or a personalized patch test were analyzed for allergen sensitization 48 to 72 hours after patch removal. These data were analyzed for allergen inclusion in the North American 80 Comprehensive Series patch test compared with the T.R.U.E. Test, as well as compared with patients with and without a history of atopic dermatitis. Of the 29 patients (mean ± SD age = 10.9 ± 5.1 years), 25 children demonstrated at least 1 positive reaction, with a total of 81 reactions overall. 40 (49.4%) of the reactions came from allergens outside of the T.R.U.E. Test, including cocamidopropyl betaine, which was frequent in patients with atopic dermatitis. Expanded and personalized patch tests provide a more comprehensive allergen inventory than the traditional T.R.U.E. Test. Pediatric patients frequently have reactions to allergens not included in the T.R.U.E. Test, and these allergens are commonly found in household products. Cocamidopropyl betaine was a particularly relevant allergen in our population. Expanded series patch testing and appropriate counseling should be provided to pediatric patients with ACD.

Experience in patch testing: A 6-year retrospective review from a single academic allergy practice

BackgroundPatch testing is the “gold standard” to identify culprit allergen(s) causing allergic contact dermatitis (ACD), but there are limited studies of patch testing from allergy practice settings. ObjectiveWe sought to explore patch test findings in a large academic allergy practice, including patch testing results, history of atopy, location of dermatitis, and referral source. We also wanted to determine whether patch testing using an extended panel, such as the North American screening series, compared with a limited series, such as the Thin-Layer Rapid-Use Epicutaneous (T.R.U.E.) Test, increased the sensitivity. MethodsA retrospective chart review was conducted of patients referred for patch testing over a 6-year period. ResultsA total of 585 patients (mean age 48.7 years, 71.6 % female) underwent patch testing over the 6-year period, of which 369 (63%) had a positive test. Of those who tested positive, 202 (55%) reported a history of atopy. The extremities were the most commonly involved site, followed by the head/neck and trunk. The 5 most common positive allergens were nickel sulfate, gold sodium thiosulfate, methylchloroisothiazolinone, thimerosal, and bacitracin. Three hundred fourteen (53.6%) patients were positive to at least 1 allergen on TRUE testing. Extended screening series identified an additional 10.8% of patients with positive tests who were negative to T.R.U.E. test allergens. ConclusionPatch testing is a valuable diagnostic tool for the practicing allergist and provides early identification of culprit allergens in ACD. Performing an extended screening series such as the North American Contact Dermatitis Group (NACDG) or supplemental panel of allergens increased sensitivity when compared with a limited series.

Analysis of the Results from the Patch Test to Para-Phenylenediamine in the TRUE Test in Patients with a Hair Dye Contact Allergy.

BackgroundPara-phenylenediamine (PPD) is the primary patch test screening agent for hair dye contact allergy (HDCA). However, no recent studies have been published that describe the results of reactions to patch tests using PPD and hair dyes in Korea.ObjectiveTo analyze the results of the patch tests to PPD using the thin-layer rapid use epicutaneous (TRUE) Test system in patients with HDCA and to investigate patients' awareness that hair dyes contains allergens, which cause the development of HDCA.MethodsEighty-four patients with suspected HDCA (32 men and 52 women) underwent patch testing using the TRUE Test system and their own hair dyes. The patients' demographic data, behavior associated with hair dyeing, and clinical manifestations of HDCA were examined retrospectively.ResultsPositive patch-test reactions to hair dyes occurred in 53.6% of patients who used hair dyes, and they were diagnosed with HDCA. Although there was a significant correlation between HDCA and PPD sensitization (p=0.001), only 40% of the patients with HDCA showed positive reactions to PPD. Of the 45 patients diagnosed with HDCA, only 7 (15.6%) were aware that their hair dyes contained allergens that caused HDCA.ConclusionThis study's findings show that PPD is an effective HDCA marker. However, we propose that investigations on hair dye components other than PPD should be conducted to develop and validate additional predictive HDCA markers.

Hyperkeratotic Hand Eczema due to Use of Rubber Gloves While Driving.

Dear Editor: Hyperkeratotic hand eczema (HHE) is defined as a lesion of hand dermatitis that shows thick hyperkeratotic plaques with or without deep fissures. This diagnosis was established in 2%~5% of patients with hand dermatitis1,2. HHE is considered to have multiple causes, such as exposure to repetitive irritation, atopy, contact allergy, and friction3. Previous studies have revealed that contact sensitization is less common in HHE2. Here, we report a case of chronic HHE associated with contact sensitization to black rubber mix and thiuram mix. A 50-year-old nonatopic male patient presented with chronic HHE that had been refractory to previous treatments for the last 2 years. Physical examination revealed relatively well-demarcated erythematous scaly plaques on the palmar sides of both hands (Fig. 1A). He was a salesman who had always driven a car to his meetings. For 3 years, he had been wearing his work gloves, which had rubber on the palmar side, to prevent his hand from sliding off the steering wheel while driving because of his palmar hyperhidrosis (Fig. 2A). He had received eczema treatment with potent topical corticosteroid creams and moisturizer at local clinics; however, his symptoms did not improve. Then, he was referred to our hospital. We performed patch tests with a thin-layer rapid use epicutaneous (TRUE) test kit (Mekos Laboratories AS, Hillerod, Denmark). There were positive reactions to thiuram mix(++) and black rubber mix(++) at 48 h, and additional positive reactions to p-tertbutylphenol formaldehyde resin(+) and p-phenylenediamine(+) at 96 h (Fig. 2B). He was advised to apply a topical steroid with medium potency and to drive without wearing gloves, and his symptoms improved 2 weeks later (Fig. 1B). Thereafter, he underwent use tests with the work gloves, which worsened his symptoms. Fig. 1 (A) Localized scaly yellowish plaques on the palmar sides of both hands. (B) Two weeks after avoiding exposure to the offending allergen. Fig. 2 (A) Blue rubber dotted work gloves. (B) Positive patch test reactions to thiuram mix(++), black rubber mix(++), p-tertbutylphenol formaldehyde resin(+), and p-phenylenediamine(+) at 96 h. A hyperkeratotic morphology is known to be less frequently associated with contact sensitization, irritant exposure, and atopic dermatitis1. Thus, strongly positive reactions to more than two materials during the patch test have clinical implications. We made a diagnosis of HHE due to repetitive use of the work gloves on the basis of the patient's history, patch tests, and use tests. Thiurams are accelerants that are commonly used to manufacture natural rubber latex products. These mixes are present in natural or synthetic rubber products making up materials that are used either at work or at home4. Many tire workers are sensitized to black rubber mix. Concerning nonoccupational exposure, it has been shown that black rubber footgear and the rubber tips of walking sticks can also cause contact dermatitis5. Positive reaction to p-tertbutylphenol formaldehyde resin is related to contact with waterproof glue, bonded leather, and construction materials, whereas that to p-phenylenediamine is related to contact with permanent or semipermanent hair dyes, dyed textiles, and cosmetics; however, these are less relevant compared with our case. In conclusion, this report suggests that patients with HHE should be comprehensively evaluated through history taking and correctly treated by avoiding the suspicious material.

The detection of clinically relevant contact allergens with a standard screening tray of 28 allergens

A standard method for diagnosing allergic contact dermatitis in the United States is the thin-layer rapid use epicutaneous (TRUE) test (TRUE Test™), which consists of three panels containing 20 individual allergens and eight allergen mixes. Previous studies had raised concern regarding the adequacy of the initial two-panel TRUE Test™ system (16 individual allergens and seven allergen mixes) in fully assessing patients with possible allergic contact dermatitis. We sought to investigate the effectiveness of the current three-panel TRUE Test™ as the sole diagnostic tool for detecting allergic contact dermatitis. This study was a retrospective analysis of 2088 patients who underwent patch testing between 1995 and 2010. Study groups were analysed to determine whether positive reactions were to allergens and/or mixes present in the TRUE Test™ panels. Of the 2088 patch-tested patients, 1385 had at least one positive reaction. Among these 1385 patients, 27.6% were fully evaluated by use of only the TRUE Test™ series, 49.9% were partially evaluated, and 22.5% did not have any of their allergens detected. On assessment for clinical relevance, similar percentages were observed. In our study, the current TRUE Test™ series of 28 allergens would have completely identified allergens in only 27.6% of patients. Broadening the standard panel to include common allergens causing >50% of allergic contact dermatitis cases in a given geographical location and aim testing allergens on the basis of the patient's history will increase the test's sensitivity.

Safety and Efficacy Evaluation of TRUE TEST Panels 1.1, 2.1, and 3.1 in Children and Adolescents

The Thin-layer Rapid Use Epicutaneous (TRUE) Test has approval for adults. To evaluate the efficacy and safety of TRUE Test panels 1.1, 2.1, and 3.1 in children and adolescents suspected of having allergic contact dermatitis (ACD). An open-label prospective study was performed, analyzing 102 consecutive patients aged 6 to 18 years referred for suspected ACD, between December 2008 and October 2009. Patch tests were applied for 48 hours, and evaluations of skin reactions were conducted at days 3 and 7, with a follow-up visit 3 weeks after the initial applications. The mean age of all enrolled subjects was 11.6 years, and subjects included 52% females and 48% males. Positive reactions noted in more than 10% of the children were to nickel sulfate (29.7%), p-tert-butylphenol formaldehyde resin (16.8%), wool alcohols (15.8%), fragrance mix (12.9%), and cobalt dichloride (12.9%). Of the 101 subjects, 77 (76.2%) tested positive to one or more of the 28 allergens. No meaningful differences were observed in the frequency or severity of adverse events; reports of burning and stinging following patch removal; or the frequency, intensity, or symptoms of persistent reactions when evaluated by age, sex, or race. Patch testing is efficacious and safe in the pediatric population.

Results of patch testing to personal care product allergens in a standard series and a supplemental cosmetic series: An analysis of 945 patients from the Mayo Clinic Contact Dermatitis Group, 2000-2007

Patch testing to a standard screening series of allergens in combination with supplemental cosmetic allergens is often used to diagnose allergic contact dermatitis due to personal care products. To report results of patch testing to skin care product allergens contained in a standard series and a supplemental cosmetic series and to compare efficacy of this combined series in detecting positive reactions to personal care product allergens with the efficacy of various standard screening series. Positive reaction rates to skin care product allergens were tabulated for patients who underwent patch testing to both standard and cosmetic series allergens at Mayo Clinic between 2000 and 2007. Data were compared with skin care allergens detected on standard screening series, including the thin-layer rapid use epicutaneous (TRUE) test. Of 945 patch-tested patients, 68.4% had at least one positive reaction and 47.3% had at least two positive reactions. Also, 49.4% of patients reacted to at least one preservative; 31.2% reacted to at least one fragrance/botanical additive. Compared with use of our standard series and cosmetic series, use of the TRUE test would have missed 22.5% of patients with preservative allergy, 11.3% with fragrance/botanical allergy, and 17.3% with vehicle allergy. Various allergens tested over time, patch test reading by residents, and lack of confirmation of allergen in personal care products. Standard patch-test screening series miss a substantial number of patients with skin care product ingredient allergy.

Patch Testing Practices of American Contact Dermatitis Society Members

Patch testing is an important part of diagnosing allergic contact dermatitis although there is much variability in methodology among practitioners. We surveyed members of the American Contact Dermatitis Society (ACDS) to quantify time spent with patients with contact dermatitis; to characterize patch testing practices, including the Thin-Layer Rapid Use Epicutaneous (T.R.U.E.) Test; and to assess utilization of the Contact Allergen Replacement Database (CARD). An electronic survey was sent to all members of the ACDS. Our survey was sent to the 600 members of the ACDS; 100 members participated (a response rate of 16.6%). Respondents used patch testing trays that contained an average of 62 allergens; 68% of respondents used the North American Contact Dermatitis Group series, and only 9% used the T.R.U.E. Test. Respondents' biggest criticism of the T.R.U.E. Test was its low number of allergens, and 94% of respondents used CARD regularly. ACDS members used patch testing trays with many allergens. Despite the T.R.U.E. Test's popularity among general dermatologists and allergists, few ACDS members used it. Routine CARD usage should be encouraged.

Patch-testing practices of American Contact Dermatitis Society members: a cross-sectional survey.

Patch testing is an example of how medicine blends art and science, resulting in differences among practitioners in methods of history taking, application of patch tests, and interpretation of results. To evaluate the "art" of patch testing (specifically, the prevalence of Thin-Layer Rapid Use Epicutaneous (T.R.U.E.) TEST use, photopatch testing, patch testing to dust mites, and immediate testing for latex allergy) as practiced by American Contact Dermatitis Society (ACDS) members and to compare the results of this survey with those of similar studies among United States dermatologists and allergists. A cross-sectional survey of all 322 members of the ACDS. The response rate was 46%. The largest proportions of respondents were male, had practiced for 11 to 20 years, were located in the northeast United States, and were in private practice. Forty percent of respondents used T.R.U.E. TEST, and 65% performed photopatch testing. Seventy percent of respondents evaluated patients for latex allergy, and 15% patch-tested to dust mites. As expected, respondents reported significantly higher prevalences of patch testing, photopatch testing, and evaluation for latex allergy than did United States dermatologists generally. Respondents reported significantly lower prevalences of single patch-test readings and use of T.R.U.E. TEST than did either general United States dermatologists or general United States allergists.

The true value of the TRUE Test for allergic contact dermatitis.

The development of the thin layer rapid use epicutaneous (TRUE) Test is a history of cooperation between scientists from academia and industry covering several disciplines: medicine, pharmaceutical chemistry, pharmacology, and statistics. The TRUE Test is today a patch test system with documented stability and allergen content. Allergens are incorporated in a dried-in-gel vehicle, which is coated onto a polyester backing to form a patch. Applied to the skin, the allergens are released when the gel becomes moisturized by transepidermal water. This may seem to be a simple technique, but its development required laborious research and solutions to stability and dosage problems. The test has been clinically standardized with serial dilution tests on sensitized patients and validated in comparative multicenter tests. The test is a significant step towards higher reliability of patch testing. Fifteen years of experience and critical investigations are discussed in this article, as are possible improvements such as expansion of the test with new allergens.