Search

Background: Propolis was added to the European baseline series (EBS) in 2019., Objectives: To investigate the frequency and relevance of positive patch tests to propolis in the EBS and to study co-reactivities., Patients and Methods: Retrospective study in patients patch tested between June 2019 and November 2023 in a university hospital in Amsterdam, The Netherlands., Results: Of 3134 consecutive patients, 299 (9.5%) had a positive reaction to propolis 10% pet. Only nine reactions (3%) were judged to be clinically relevant. There were significant co-reactivities to Myroxylon pereirae resin (balsam of Peru), colophonium, fragrance mixes 1 and 2, and to limonene and linalool hydroperoxides. A steep increase in rates of positive reactions to propolis was observed from 2020 to 2023. This was highly likely the result of the replacement of Chinese propolis with Brazilian propolis by the manufacturer., Conclusions: Positive patch tests for propolis are very frequent in Amsterdam, but only a few of these reactions are relevant. Most are probably (pseudo-)cross-reactions in patients with fragrance allergies. Propolis in the EBS has very limited value for dermatologists and patients in The Netherlands. Changes in patch test materials should be provided to all users to avoid misinterpretation of patch test results., (© 2024 The Author(s). Contact Dermatitis published by John Wiley & Sons Ltd.)

Background: Patch testing for multiple cross-reactive allergens for allergic contact dermatitis (ACD) may not be necessary because of copositivity., Objectives: We evaluated the formaldehyde group allergens to determine the optimal, most cost-effective allergens to test., Methods: A retrospective analysis of Mayo Clinic (1997-2022) examined the well-established copositive formaldehyde group: formaldehyde, quaternium 15, hexahydro-1,3,5-tris(2-hydroxyethyl)triazine, diazolidinyl urea, imidazolidinyl urea, toluenesulphonamide formaldehyde resin, DMDM hydantoin, and ethyleneurea melamine formaldehyde mix. Patch Optimization Platform identified which single formaldehyde-related allergen optimally captures patients with clinically relevant ACD. Next, Patch Optimization Platform determined the optimal additional 1, 2, 3, etc. allergens. Cost per patch test was $5.19 (Medicare 2022)., Results: A total of 9832 patients were tested for all listed allergens, with 830 having positive patch test results. Patch Optimization Platform determined that quaternium 15 alone captures 53% of patients with ACD to the formaldehyde group; adding the optimal second allergen (formaldehyde 1%) captures 78%; the optimal 5 top allergens capture >94% of patients. The incremental cost per additional diagnosis increased up to 44-fold as the number of allergens tested increased., Limitations: Data are from a single institution, and the cost per test was fixed according to Medicare Part B in 2022., Conclusions: For diagnosing ACD, we recommend considering an optimized allergen selection algorithm., Competing Interests: Conflicts of interest None disclosed., (Copyright © 2024 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.)

Drug causality assessment in severe cutaneous adverse reactions (SCARs) remains challenging. We investigated the usefulness of in-vivo drug patch tests (PT), ex-vivo interferon (IFN)-γ enzyme-linked immunospot (ELISpot) assay, and lymphocyte transformation test (LTT) in 30 SCARs patients within the past 36 months. Drug PT yielded a 20% positivity rate (n = 6), while IFN-γ ELISpot and LTT showed positive rates of 56.67% (n = 17) and 41.38% (n = 12), respectively. Combining the three tests resulted in an overall positive rate of 66.67% (n = 20) of cases. IFN-γ ELISpot offered additional positivity, especially with oxypurinol. Employing a combined diagnostic approach may enhance the chances of obtaining a positive result., (© 2024 Japanese Dermatological Association.)

Background: Machine learning (ML) offers an opportunity in contact dermatitis (CD) research, where with full clinical picture, may support diagnosis and patch test accuracy., Objective: This review aims to summarise the existing literature on how ML can be applied to CD in its entirety., Methods: Embase, Medline, IEEE Xplore, and ACM Digital Library were searched from inception to February 7, 2024, for primary literature reporting on ML models in CD., Results: 7834 articles were identified in the search, with 110 moving to full-text review, and six articles included. Two used ML to identify key biomarkers to help distinguish between allergic contact dermatitis (ACD) and irritant contact dermatitis (ICD), three used image data to distinguish between ACD and ICD, and one used clinical and demographical data to predict the risk of positive patch tests. All studies used supervision in their ML model training with a total of 49 704 patients across all data sets. There was sparse reporting of the accuracy of these models., Conclusions: Although the available research is still limited, there is evidence to suggest that ML has potential to support diagnostic outcomes in a clinical setting. Further research on the use of ML in clinical practice is recommended., (© 2024 The Author(s). Contact Dermatitis published by John Wiley & Sons Ltd.)

Introduction: The growing presence of allergens in materials and scarce data on allergic contact dermatitis in children has increased our need to refine its diagnosis in this population. We aimed to analyze children's specific responsivity to highly reactive subcomponents of Fragrance mix I, Fragrance mix II, and Textile dye mix from the European baseline series., Methods: We retrospectively analyzed patch test records of children aged 2 to 18 who underwent patch testing with the European baseline series between 2014 and 2022 in Israel., Results: A total of 367 children were included in the study. In all, 160 children had positive results; 43 patients reacted to one of the mixes, and 20 performed further testing. Eleven of them completed the extended series at the exact same times as the regular European series, which benefited children. Farnesol was the most reactive compound (30.8%)., Conclusions: Performing the extended European series provides a more accurate and time-efficient allergic contact dermatitis diagnosis. Farnesol reactivity appears prominent in children and may justify tighter product regulations., (© 2024 the International Society of Dermatology.)

Background: Isocyanates are used as starting materials of polyurethane (PU) products. They are relatively important occupational skin sensitizers., Objectives: To analyse results of a large isocyanate patch test series of 19 isocyanate test substances and 4,4'-diaminodiphenylmethane (MDA), a marker of 4,4'-diphenylmethane diisocyanate (MDI) hypersensitivity., Methods: Test files were screened for positive reactions in the isocyanate series. Patients with positive reactions were analysed for occupation, exposure and diagnosis., Results: In 2010-2019, 53 patients had positive reactions in the series (16% of 338 patients tested). MDA, the well-established screening substance for MDI allergy, was positive in 30 patients, an in-house monomeric MDI test substance in 23 patients and 3 different polymeric MDI test substances in 19-21 patients. We diagnosed 16 cases of occupational allergic contact dermatitis (OACD) from MDI including 3 pipe reliners. Hexamethylene-1,6-diisocyanate (HDI) oligomers in paint hardeners caused 5 cases of OACD, more cases than 2,4-toluene diisocyanate (TDI; n = 3) and isophorone diisocyanate (IPDI; n = 1) put together., Conclusions: In contrast to previous studies, polymeric MDI test substances were not superior to a monomeric MDI. Pipe reliners may get sensitised not only by epoxy products and acrylates but also by MDI in hardeners of PU pipe coatings. HDI oligomers were the second most important causes of OACD after MDI., (© 2024 The Author(s). Contact Dermatitis published by John Wiley & Sons Ltd.)

Background The International Contact Dermatitis Research Group (ICDRG) grading is the gold standard and is used to interpret patch test results in allergic contact dermatitis (ACD). The ICDRG readings include a combination of visual and palpation findings. Digital photography limits palpation. An alternative scoring system exists to analyse 2D images and interpret patch test readings in teledermatology (TD). Aim To compare tri-partite scoring system (TPSS) (TD) with ICDRG (face-to-face) and to assess the feasibility of TPSS by TD. Methods In this observational study, two investigators each scored the patch test readings for 78 patients at the 48th h, 96th h and on the 7th day. Results The TPSS has a sensitivity of 100%, specificity of 93.34%, positive predictive value of 91.67% and negative predictive value of 100%. At a confidence interval of 95%, Cohen's kappa (0.90) indicated excellent agreement between both investigators. The concordance between both scoring systems was at 93.2% for agreement and 6.82% for disagreement. Polysensitisation (6 patients with 16 allergens) was detected equally in both methods. Limitation A single centre study. Conclusion The readings obtained by TPSS were in agreement with ICDRG. TPSS can reduce the number of patient visits by 50% and may be used during COVID-19 times and beyond.

Background: The number of commercially available plant allergens/extracts is limited and therefore patch testing with fresh/dried plant material may be a necessary supplement in diagnosing plant allergy., Objectives: To evaluate the usefulness of patch testing with plants "as is" compared to patch testing with commercial and in-house produced plant test materials and to report on species eliciting positive patch test reactions., Patients/materials/methods: Consecutive eczema patients, who were patch tested between January 2019 and December 2023 and who had at least one positive reaction to a plant allergen and/or extract and/or plant "as is" were included in the study., Results: A total 57 out of 1893 patients tested (3%) were sensitised to plants. Compositae plants were the most frequent sensitizers, followed by tomato, tulipalin A, falcarinol, and Philodendron plants. In 12 patients (21%), the diagnosis was based on patch testing with fresh plants only. Occupational sensitization occurred in 32%. Other sensitizers included Hydrangea, Pelargonium zonale, and Monstera., Conclusions: A large minority of plant-sensitised patients would have been undiagnosed without patch testing with plants "as is." Most of the culprit plants were known sensitizers, but not commercially available, and these and new species taken into cultivation makes patch testing with fresh plants unavoidable and worthwhile., (© 2024 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Existing literature has questioned the sensitivity of patch testing (PT) with cotrimoxazole (CTX) in the study of drug hypersensitivity., Objectives: Assess the sensitivity of PT with CTX in non-immediate cutaneous adverse drug reactions (CADR)., Patients/materials/methods: Retrospective analysis (2000-2022) of PT with an antibiotic series including CTX 10% pet (Chemotechnique Diagnostics©) performed according to ESCD guidelines in patients with suspected non-immediate CADR reactions to CTX. Some patients were additionally tested with in-house preparations of CTX from Bactrim DS® tablets at 10% in pet or water and trimethoprim 10% pet (Laboratórios Edol©)., Results: Sixty-four patients (48F/16M; mean age 47 ± 18) were included, mostly with maculopapular exanthema (51, 80%). Notably, CTX was sole suspect in 24 patients. There was no positive reaction to CTX at 10% from Chemotechnique or Bactrim DS® tablets prepared at 10% pet for patch testing. One patient reacted exclusively to trimethoprim with 1+ reaction. Two patients had a faint reaction (1+) only with the powder of Bactrim DS® tablets in water at D2, but as the reactions faded completely in 24 or 48 h, they were interpreted as irritant non-specific reactions., Conclusion: These findings suggest that patch testing may lack sufficient sensitivity to diagnose CTX-induced non-immediate CADR. Therefore, clinicians should be cautious interpreting CTX patch test results., (© 2024 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Photoallergic contact dermatitis (PACD) is a delayed hypersensitivity reaction to allergens only in the presence of ultraviolet radiation in sunlight. Photopatch testing (PhotoPT) is necessary to confirm the diagnosis of PACD. There are few published studies of PhotoPT in North America., Objective: To summarise the results of patients photopatch tested by members of the North American Contact Dermatitis Group (NACDG), 2009-2020., Methods: Retrospective analysis of patient characteristics and PhotoPT results to 32 allergens on the NACDG Photopatch Test Series., Results: Most of the 454 tested patients were female (70.3%), 21-60 years old (66.7%) and White (66.7%). There were a total of 119 positive photopatch tests. Sunscreen agents comprised 88.2% of those, with benzophenones responsible for over half of them. Final diagnoses included PACD in 17.2%, allergic contact dermatitis (ACD) in 44.5%, polymorphous light eruption (PMLE) in 18.9% and chronic actinic dermatitis (CAD) in 9.0% of patients., Conclusions: In 454 patients with suspected photosensitivity referred for photopatch testing in North America, approximately one-fifth had PACD. Sunscreen agents, especially benzophenones, were the most common photoallergens. Other common diagnoses included ACD, PMLE and CAD. Photopatch testing is an important tool for differentiating these conditions., (© 2024 The Author(s). Contact Dermatitis published by John Wiley & Sons Ltd.)

Patch testing is the only clinically applicable diagnostic method for Type IV allergy. The availability of Type IV patch test (PT) allergens in Europe, however, is currently scarce. This severely compromises adequate diagnostics of contact allergy, leading to serious consequences for the affected patients. Against this background, the European Society of Contact Dermatitis (ESCD) has created a task force (TF) (i) to explore the current availability of PT substances in different member states, (ii) to highlight some of the unique characteristics of Type IV vs. other allergens and (iii) to suggest ways forward to promote and ensure availability of high-quality patch testing substances for the diagnosis of Type IV allergies throughout Europe. The suggestions of the TF on how to improve the availability of PT allergens are supported by the ESCD, the European Academy of Allergy and Clinical Immunology, and the European Academy of Dermatology and Venereology and intend to provide potential means to resolve the present medical crisis., (© 2024 The Authors. Contact Dermatitis published by John Wiley & Sons Ltd.)

Background: Increasing trends of oxidized linalool contact allergy have been reported. However, the impact of reactivity and dose in eliciting allergic contact Dermatitis caused by linalool hydroperoxides is insufficiently investigated. Objectives: To perform repeated open application tests (ROATs) using the real-world concentrations of linalool hydroperoxides in patients and control participants. Materials and Methods: Patients who previously had a positive (patients) and a negative (controls) patch test reaction to linalool hydroperoxides 1.0% in petrolatum were patch tested with a dilution series of linalool hydroperoxides preparations and asked to perform ROAT twice daily with 3 concentrations of linalool hydroperoxides creams and a negative control cream for 28 days. The creams contain 44, 140, and 440 PPM of linalool hydroperoxides, representing real-world doses reported in consumer products. Results: Of all 47 participants, 31 were linalool hydroperoxides contact allergy patients, and 16 were controls. One patient had a positive ROAT reaction in the area where cream at the highest concentration of linalool hydroperoxides was applied for 28 days. Conclusions: Repeated exposure to creams containing linalool hydroperoxides at real-life concentrations could rarely elicit an allergic reaction on intact skin after 4 weeks.

Background: Patch test is the gold standard for diagnosing allergic contact dermatitis. Conventionally, the patches are applied for 48 h, which in tropical weather conditions causes excessive sweating, leading to irritation, and sometimes the patches come off, making the test inconclusive., Objective: To compare the patch test positivity after 24 and 48 h of occlusion time in patients of allergic contact dermatitis, using standard allergen concentration., Materials and Methods: Clinically suspected patients of allergic contact dermatitis were enrolled and patch tested using the Indian Standard Series, parthenium acetone extracts (1:50, 1:100 and 1:200 dilutions) and patient material. Patches were applied in duplicate on either side of the back, using a random number table. One set of patches was removed after 24-h of occlusion, while the other set after 48-h. Readings were performed at 48- and 96-h by two independent dermatologists, blinded to the duration of occlusion., Results: The study had 97 adult patients (58 males and 39 females; mean age: 48.12 ± 13.07 years). A total of 133 and 142 positive reactions were observed after 48 h occlusion at 48 and 96 h reading, respectively. Of these 117 (87.9%) and 132 (92.9%) patches were positive and concordant and noted at 24 h occlusion time. The Cohen's kappa coefficient were 0.94 for 48 h and 0.97 for 96 h reading, hence showing an almost complete agreement (ⱪ > 0.81) between patches occluded for 24 and 48 h., Conclusion: Though there is no significant difference in patch test positivity among ISS allergens after either occlusion time, 48 h occlusion performs significantly better compared with 24 h, when reactions of all allergens (ISS, patient material and parthenium acetone extract) are analysed together., (© 2024 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Exogenous allergens, found in cosmetic products, jewelry items, antiseptics and antibacterials, plants, and solvents, can cause clinical allergic contact Dermatitis (ACD). To help identify and discern which allergen is causing ACD, clinicians use patch tests, but they can yield false-negative results at times. Examining potential reasoning for false negatives is particularly helpful when a patient's history and physical examination strongly suggest ACD, and the patch test is negative. A strong history and physical presentation suggestive of ACD warrants additional patch testing or other methods to verify a false-negative patch test result. We conducted a literature review to compile various reasonings and solutions for false-negative patch tests in suspected ACD patients. Utilizing EMBASE, Scopus, PubMed, and Google Scholars, 49 articles were included by using search terms such as "False negative patch test" or "False-negative patch test" and "allergic contact Dermatitis," or "ACD." Common factors that led to false-negative patch test results include low allergen concentration, inadequate percutaneous penetration, technique error, immunosuppressive therapy, and ultraviolet exposure. Potential solutions include using different vehicles, concentration, increasing reading time, repeating the patch test, intradermal testing, and repeat open application testing. If a false-negative patch test is suspected, then intradermal testing can be administered to ensure the specificity of the patch test result. Considering the main contributing factors and solutions to false-negative patch tests, clinicians can accurately diagnose ACD and administer proper treatment plans.

Background: Supplemental patch testing is an adjunct to standard patch test screening series. Objective: To determine the demographics, characteristics, frequency, relevance, and interpretation of patch test reactions for supplemental patch testing. Methods: Retrospective study of patients tested 2017-2020 with North American Contact Dermatitis Group (NACDG) and supplemental screening series (Supplemental Series A [SSA], Supplemental Series B [SSB]). Demographics, characteristics, reaction strengths, relevance, and final interpretation were recorded. Results: Cohort included 791 patients; 73.5% female, 68.6% age >40 years. 74.1% were White, 15.2% Black, 5.7% Asian, and 1.5% Hispanic. The most common Dermatitis sites were scattered/generalized (27.2%), face (24.0%), and hands (23.5%). For 2017-2018 and 2019-2020, respectively, 82% (318/388) and 78.4% (316/403) had ≥1 "allergic" reaction. In addition, 13.5% (52/385) and 11.7% (47/403) had SSA reactions, and 38.1% (115/302) and 31.5% (101/321) had SSB reactions. In the 87 (2017-2018) and 99 (2019-2020) patients with negative NACDG testing, 17 (19.5%) and 12 (12.1%) had supplemental reactions. Of the 34 supplemental allergens with reaction frequency ≥1%, 58.8% (20/34) are not part of the American Contact Dermatitis Society 90 (2020) or NACDG 2021-2022 screening series. The highest frequency allergens from this group were dodecyl and octyl gallate, cinnamic alcohol, phenyl salicylate, hexahydro-1,3,5-tris-(2-hydroxyethyl) triazine, and abitol. Conclusions: Supplemental patch testing identifies additional relevant allergens in patients with suspected allergic contact Dermatitis.

Background: Allergic contact Dermatitis (ACD) is a common condition within the pediatric population. Patch testing is an important way to identify relevant allergens. Objective: To provide an update of the common contact allergens seen in children based on patch testing data at our institution from 2016 to 2020. Methods: We performed a retrospective analysis of patch test data from children aged 1-18 years from 2016 to 2020 at Mayo Clinic. Reaction rates were compared to the rates reported by the Pediatric Contact Dermatitis Registry (PCDR). Results: One hundred ninety-two children aged 1-18 were patch tested to various allergens. A total of 15,457 allergens were tested, with 291 positive tests. The top 5 allergens with highest positive reaction rates were hydroperoxides of linalool, hydroperoxides of limonene, methylisothiazolinone, nickel, and cobalt. Seven of the top 38 allergens with the highest reaction rates are not currently included in the Mayo Clinic Pediatric Patch Test Series, and 11 are not currently included in the Pediatric Baseline Series (as developed by the Pediatric Contact Dermatitis Workgroup). Conclusions: Patch testing is a useful tool to diagnose children with ACD. With new products and exposures, there is an opportunity to expand current pediatric patch testing series.

Background: Quantitative risk assessment (QRA) for skin sensitization is used to derive safe use levels of sensitising fragrance ingredients in products. Post-marketing surveillance of the prevalence of contact allergy to these ingredients provides relevant data to help evaluate the performance of these measures., Objectives: To determine a suitable patch test concentration for five fragrance materials that had hitherto not been tested on a regular basis. These concentrations are then to be used in a surveillance study with patch testing consecutive patients over an extended monitoring period., Materials and Methods: Furaneol, CAS.3658-77-3; trans-2-hexenal, CAS.6728-26-3; 4,8-dimethyl-4,9-decadienal, CAS.71077-31-1; longifolene, CAS.475-20-7; benzaldehyde, CAS.10052-7, were patch tested with other fragrance allergens in four clinics. Patch testing was conducted in three rounds, starting with the lowest concentrations of the five ingredients. The doses were increased in the subsequent rounds if no late-appearing positive reactions and virtually no irritant reactions were reported., Results: Overall, 373 patients were tested. No positive allergic reaction was reported to the five ingredients. Patch test results of other fragrance allergens are reported., Conclusions: The highest test concentrations are each considered safe for patch testing consecutive patients. Further surveillance based on these preparations will evaluate the hypothesis that QRA-driven consumer product levels of these fragrances can prevent sensitization., (© 2024 The Authors. Contact Dermatitis published by John Wiley & Sons Ltd.)

Background: Doubtful reactions in patch testing are infrequently reported in the literature; however, recent reports have suggested they be assessed with the same scrutiny as stronger reactions., Objective: Assess the clinical relevance of doubtful reactions in patch testing., Methods: Retrospective study of 1514 patients comprehensively patch tested via the NACDG standard series and additional allergens based on history. The clinical relevance of each reaction was graded based on the NACDG scale: definite, probable, possible, past, unknown and irritant. Reactions were considered 'unique' if an additional mild-to-strong reaction to the same chemical at a different concentration was not observed., Results: 68.9% (1043) of patients demonstrated at least 1 doubtful reaction. Of 4453 total doubtful reactions, 92.2% (4106) were unique. Only 3.3% (137) and 12.2% (500) of these were determined to be of definite or probable clinical relevance respectively. 'Fragrance' was the most common allergen family present among the unique definite doubtful reactions (37). However, 24 (64.9%) of these also had a stronger reaction to another fragrance. Cocamidopropyl betaine was the second most frequent allergen demonstrating definite doubtful reactions (27) and unique in 85.2% (23) of cases. Methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) was most prevalent (36) but less frequently unique (58.3%, 21)., Conclusions: Doubtful reactions may not be as impactful to clinical decision making as theorised in the literature. Few demonstrate definite clinical significance, and many have related stronger reactions that capture them for clinical purposes. Identification of doubtful reactions to cocamidopropyl betaine and MCI/MI may be of greatest significance as they most frequently were not supported by stronger reactions., (© 2024 The Authors. Contact Dermatitis published by John Wiley & Sons Ltd.)

Introduction: Atopic dermatitis (AD) is a chronic and relapsing inflammatory skin disease mainly affecting children. Similarly, Allergic contact dermatitis (ACD) is an inflammatory skin disease, but unlike AD it results from direct exposure to an external agent. Theoretically, the impaired skin barrier facilitates the penetration of potential allergens. Therefore, AD patients are at risk for an associated ACD, exacerbating their skin condition. Because eczema is similar, performing a patch test (PT) for the differential diagnosis is essential., Methods: In this cross-sectional transversal study, we performed a PT with 30 sensitizers in 26 children with AD, selected according to established criteria for suspected ACD, and treated at an AD center of a pediatric university hospital in Rio de Janeiro. Clinical presentation, patient profile, main sensitizers, and frequency of ACD caused by therapeutic skincare products were evaluated., Results: In all, 23 (88.5%) patients reacted to at least one allergen, 21 (80.7%) had a relevant positive patch test, and 15 (57.7%) were polysensitized. The main positive sensitizers were nickel (38.5%), blue disperse (30.8%), fragrance mix (30.8%), and neomycin (23.1%). Nineteen (73%) patients reacted to substances present in therapeutic or skincare products., Conclusion: Our data underscore the importance of performing a PT in AD children whose eczema has atypical distribution. The expressive percentage of positive tests, especially of allergens in skincare products, indicates the constant need to review the proposed treatments. Therefore, we recommend a specific and expanded PT battery for pediatric AD patients, including a negative control, to increase sensitivity for diagnosing ACD., Competing Interests: The authors declare no potential conflicts of interest regarding this article's research, authorship, and/or publication.

Background: Allergic contact Dermatitis® (ACD) in older adults (OA) represents a significant health burden, but few studies examine the prevalence and characteristics of contact allergy and ACD in this population. Objective: To compare positive and clinically relevant patch test results in OA versus younger adults (YA) and children. Methods: Retrospective analysis of patch test results obtained in OA (≥65 years), YA (19-64 years), and children (≤18 years) by the North American Contact Dermatitis® Group, 2009 to 2020. Results: Of 28,177 patients patch tested, 5366 (19.0%) were OA. OA were more likely to have a final primary diagnosis of ACD as compared with YA (50.8% vs 49.2%, P  = 0.035) and children (44.6%, P  < 0.0001). The primary site of Dermatitis® also differed by age group, with OA having a higher proportion of Dermatitis® affecting the trunk, scalp, anogenital region, and "under clothing," and a lower proportion of Dermatitis® affecting the face, lips, and feet. Limitations: Retrospective design, lack of follow-up, and referral population. Conclusion: OA were as likely and were statistically even more likely to have a final primary diagnosis of ACD compared with YA and children. Anatomic site of Dermatitis® also differed by age group. This underscores the need for patch testing in OA when ACD is suspected.

Allergic contact dermatitis (ACD) is a common inflammatory skin disease caused by delayed hypersensitivity to chemical and biotic contact allergens. ACD significantly affects the patients' quality of life negatively impacting both occupational and non-occupational settings. Patch testing is the gold standard diagnostic in vivo test to precise the ACD etiology and to correctly perform prevention. According to the Italian Medicines Agency (AIFA) legislative decree no. 178 of 29 th May 1991, allergens are defined as medicines and therefore they are subject to strict regulation. In 2017, AIFA (decree no. 2130/2017) started a procedure to regulate contact allergens on the Italian market and actually the contact allergens temporarily authorized are reported in AIFA decree no. 98/2022, valid until November 2023. The availability on the market of contact allergens to diagnose ACD and continuous updating on the basis of new epidemiological trends are mandatory, jointly with the continuous update of the baseline and integrative series for patch testing. For this reason, the scientific community represented in Italy by the Skin Allergies Study Group of SIDeMaST (Italian Society of Dermatology and Venereology) and SIDAPA (Italian Society of Allergological, Occupational and Environmental Dermatology) are constantly working, in close relationship with the European scientific communities with large expertise in this important sector of the modern Dermatology. Herein, we report the setting up of regulatory legislation by AIFA and the new Italian Adult Baseline Series for patch testing.

Background/objectives: Carvone, a flavoring agent, may cause allergic contact dermatitis. This study summarizes patch test reactions to carvone in patients tested by the North American Contact Dermatitis Group, 2009 to 2018., Methods: This was a retrospective analysis of patients positive to carvone (5% petrolatum). Demographics were compared with those of patients who were negative. Other analyses included reaction strength, clinical relevance, coreactivity with other fragrance/flavor allergens, and exposure sources., Results: Of 24,124 patients tested to carvone, 188 (0.78%) were positive. As compared with carvone-negative patients, carvone-positive patients were significantly more likely older than 40 years (P = 0.0284). Women (76.1%) and/or facial involvement (33.0%) were common in the carvone-positive group but not statistically different from carvone-negative patients; 73.3% (n = 138) of the reactions were currently relevant. Relevant sources were personal care products (46.3%, n = 87) and food (14.3%, n = 27). Coreactivity with other fragrance/flavor markers was present in 60.6% of carvone-positive patients, most commonly fragrance mix I (34.6%), balsam of Peru (24.5%), and cinnamic aldehyde (15.4%)., Conclusions: Ten-year prevalence of carvone sensitivity was 0.78%. Most carvone-positive patients were female, were older than 40 years, and/or had facial dermatitis. Personal care products were the most common source. Two-fifths of carvone reactions would have been missed by relying on other fragrance/flavoring allergens., (Copyright © 2021 American Contact Dermatitis Society. All Rights Reserved.)

Background: Ethylhexylglycerin (EHG) is a recently recognized contact allergen., Objective: The aims of the study were to characterize individuals with positive patch test reactions to EHG and to analyze reaction strength, clinical relevance, and allergen sources., Methods: This study was a retrospective analysis of the patients patch tested to EHG (5% petrolatum) by the North American Contact Dermatitis Group (2013-2018)., Results: Of 15,560 patients tested to EHG, 39 (0.25%) had positive (final interpretation of "allergic") reactions. Most were female (71.8%) and/or older than 40 years (76.9%). There were no statistically significant differences between age, sex, or atopic history when compared with EHG-negative patients. The most common anatomic sites of dermatitis were the face (28.2%) and scattered generalized distribution (25.6%). Most EHG-positive reactions were + (35.9%) or ++ (33.3%). Current clinical relevance was high (79.5%); none, however, were related to occupation. Personal care products were the most common source of exposure to EHG (59.0%)., Conclusions: Ethylhexylglycerin is a rare contact allergen; the positive frequency of 0.25% is similar to other low allergenic preservatives including parabens, benzyl alcohol, and phenoxyethanol. The patch test concentration of 5.0% seems to be nonirritating. Although relatively uncommon, EHG reactions were usually clinically relevant (79.5%), often because of moisturizers/lotions/creams., Competing Interests: A.R.A. received a Pfizer Independent Grant for Learning and Change and has consulted for Henkel. J.S.T. owns shares of stock in AstraZeneca, Cigna, Merck, Johnson & Johnson, and OPKO Health. He has consulted for Kao Brands and Monsanto (Bayer), is a member of the Cosmetic Ingredient Review Steering Committee, and has a nondependent child employed by Pfizer. E.M.W. has received an investigator-initiated grant from and served as a consultant for WEN by Chaz Dean. D.S. receives royalties from UpToDate (Wolters Kluwer Health). The other authors have no funding or conflicts of interest., (Copyright © 2021 American Contact Dermatitis Society. All Rights Reserved.)

Abstract: Exposure to elemental aluminum and its salts is unavoidable. Aluminum as a metal is present in transport, construction, packaging, and electronic equipment. Aluminum salts are present in consumer products, food items and drinking water, vaccines, drugs, and antiperspirants. Aluminum in vaccines and preparations for allergen-specific immunotherapy are the major sensitization sources. The predominent clinical manifestations of aluminum allergy are pruritic subcutaneous nodules and eczematous dermatitis. Patch testing shall be performed with aluminum chloride hexahydrate (ACH) in petrolatum. The preparation with ACH 10% detects substantially more aluminum allergy than ACH 2%. A patch test with elemental aluminum, for example, an empty Finn Chamber, is only positive when there is a strong aluminum allergy. A patch test reading should be performed 1 week after the application so as not to miss 15% to 20% of aluminum allergy. Aluminum should be included in any baseline patch test series for children and investigated for a possible inclusion in baseline series for adults. Aluminum test chambers can interfere with the testing resulting in both false-negative and false-positive patch test reactions to nonaluminum contact sensitizers., Competing Interests: The authors have no funding or conflicts of interest to declare., (Copyright © 2021 American Contact Dermatitis Society. All Rights Reserved.)

Background: Hair care products (HCPs) may cause both allergic contact dermatitis (ACD) and irritant contact dermatitis (ICD)., Objectives: The aims of the study were to determine the prevalence of HCP-associated ICD/ACD and to characterize relevant allergens., Methods: This study is a retrospective analysis of North American Contact Dermatitis Group (NACDG) patch test data, 2001-2016., Results: Of 38,775 patients tested, 3481 (9.0%) had positive patch test reactions associated with HCPs. The HCP-positive patients were significantly more likely to be female (79.9% vs 66.0%) and/or have primary sites of dermatitis on the face (32.0% vs 27.8%) or scalp (15.4% vs 2.2%) compared with the HCP-negative patients (P < 0.0001). Of 4908 HCP-associated positive patch test reactions, 86.9% (n = 4263) were due to allergens on the NACDG screening series; p-phenylenediamine (35.8%), methylisothiazolinone (9.7%), methylchloroisothiazolinone/methylisothiazolinone (8.7%), and cocamidopropyl betaine (5.9%) were the most frequent. Most reactions (87.7%, 3736/4263) were currently clinically relevant. The most common job associated with 366 occupationally related NACDG HCP-associated allergens was hairdresser/cosmetologist (71.9%). Two hundred eighty-two patients (0.7%) had ICD associated with HCPs. Shampoo/conditioners were the most frequent source of NACDG HCP-associated reactions (47.3%) and HCP-associated ICD (45.0%)., Conclusions: Of the HCP-positive patients, 18.5% had HCP reactions to allergens not on the NACDG screening series, underscoring the importance of patch testing to expanded series in patients suspected of HCP allergy., Competing Interests: A.R.A. received a Pfizer Independent Grant for Learning & Change and has consulted for Henkel. E.M.W. has received research funding from WEN by Chaz Dean. She has also served as a consultant for Noven Pharmaceuticals, Inc, and WEN by Chaz Dean. J.S.T. owns shares of stock in AstraZeneca, Cigna, Merck, Johnson & Johnson, and OPKO Health. He has consulted for Kao Brands and Monsanto (Bayer), is a member of the Cosmetic Ingredient Review Steering Committee, and has a nondependent child employed by Pfizer. Sasseville receives royalties from UpToDate (Wolters Kluwer Health). The other authors have no funding or conflicts of interest to declare., (Copyright © 2021 American Contact Dermatitis Society. All Rights Reserved.)

Background: Contact allergy to oxidized (ox.) linalool and ox. limonene has been reported to have a high prevalence, raising the question of inclusion into the baseline series. However, several important issues should be clarified and further investigated before inclusion can be warranted., Objectives: To report the trends of ox. terpenes allergy in patients with dermatitis, features of the patch test reactions, and clinical characteristics of the patients., Methods: A retrospective analysis of 5773 patients was performed. All patients were patch tested with baseline series, individual ingredients of fragrance mix I and II, ox. linalool, and ox. limonene from 2013 to 2020., Results: The prevalence rates of contact allergy to ox. linalool and ox. limonene were 7.0% and 5.1%, respectively. Significantly increasing trends of contact allergy were observed. More than 95% of contact allergy cases were identified on Day 3/4. Patients with contact allergy to ox. linalool and ox. limonene were significantly younger than those with contact allergy to other fragrances and were predominantly female. Strong reactions were associated with older age and multiple fragrance allergies., Conclusions: Contact allergy to ox. linalool and ox. limonene is becoming increasingly important, and findings show intriguing features. More studies concerning the clinical relevance before recommending these substances for screening are required., (© 2021 The Authors. Contact Dermatitis published by John Wiley & Sons Ltd.)

Background: Patch tests (PTs) with two readings have been used for decades to identify the culprit drug in nonimmediate cutaneous adverse drug reactions (NICADRs), followed more recently by late reading of intradermal tests (IDTs). Some teams tend to perform PTs with only one reading before IDTs or even directly perform IDTs., Objectives: To evaluate the relevance of a late PT reading on day 4 (D4) in NICADRs., Methods: We retrospectively selected patients who had a PT for an NICADR between July 2014 and March 2020., Results: During the study period, 328 patients had a PT with available results. Among the 75 positive-PT patients with available data for the two readings, 41 (54.7%) had positive results on D2 and D4 and 34 (45.3%) had negative results on D2 but positive results on D4. No patient had positive results on D2 and negative results on D4., Conclusion: This study shows that a D4 reading enhanced the PT-positive results. A positive PT result allows for reducing the number of IDTs, which are more difficult and costly to perform. Our series suggests that a late PT reading at D4 should be performed for exploring NICADRs., (© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Recently, aluminum chloride hexahydrate (ACH) 10.0% petrolatum (pet) was recommended for patch testing to detect aluminum contact allergy. Aluminum lactate (AL) may be as reliable a test substance as ACH., Objective: We aimed to investigate the frequencies of aluminum allergy when ACH and AL were used in patch testing consecutive patients., Methods: Petrolatum preparations of ACH 10.0% and AL 12.0% were added to the baseline series in 2010-2017. Aluminum chloride hexahydrate 10.0% pet was added to the children baseline series from July 1, 2012, to December 31, 2017., Results: A total of 5448 patients were patch tested with the extended baseline series and 196 children with the extended children baseline series. Forty-eight of the 5448 adults (0.9%) and 10 of the 196 children (5.1%) were diagnosed with aluminum contact allergy. A significant difference was found between the aluminum allergy frequencies in children and adults patch tested with ACH in 2013-2017 (P < 0.001). The difference between the frequencies of contact allergies for the 2 aluminum salts is not statistically significant., Conclusions: Patch testing with ACH and AL demonstrated similar contact allergy frequencies. To detect aluminum allergy, patch testing with ACH 10.0% pet is recommended. Aluminum chloride hexahydrate 10.0% pet should be considered for inclusion in baseline series for patch testing adults and children., Competing Interests: The authors have no funding or conflicts of interest to declare., (Copyright © 2021 American Contact Dermatitis Society. All Rights Reserved.)

Objective: We sought to determine the incidence of RFDD in patients receiving dupilumab and the rate of resolution of RFDD after expanded series patch testing (ESPT) and allergen avoidance., Methods: This is a retrospective chart review of 80 patients with atopic dermatitis who were evaluated for RFDD after treatment with dupilumab. Expanded series patch testing findings and response to allergen avoidance were assessed in the subset of patients with RFDD who subsequently underwent ESPT while continuing to receive dupilumab., Results: Forty-nine patients (61.3%) experienced facial dermatitis before initiating dupilumab. Thirty-five patients (43.8%) experienced RFDD after starting dupilumab. Of the 14 patients with RFDD who received ESPT, 92.9% had 1 or more relevant positive patch test results, with 50% of such patients being mostly to completely clear of facial dermatitis after allergen avoidance. Importantly, 50.6% of the positive reactions to allergens were not included on the North American Contact Dermatitis Group Core 80., Conclusions: Many patients with RFDD benefit from patch testing and subsequent allergen avoidance. Expanded series patch testing should be offered to patients who experience RFDD after beginning dupilumab therapy to ensure that such patients have eliminated any exogenous component of their dermatitis, such as concomitant allergic contact dermatitis., Competing Interests: J.E.M. has participated in advisory boards for Genzyme/Sanofi, Eli Lilly, Dermira, and UCB; participated in disease statement management talks for Regeneron and UCB; and provided dermatologic consulting services for UpToDate. The remaining authors have no funding or conflicts of interest to declare., (Copyright © 2021 American Contact Dermatitis Society. All Rights Reserved.)

Background: Parents report that children with aluminium contact allergy and vaccination granulomas may react to aluminium-containing sunscreen following application., Objectives: To evaluate whether contact dermatitis develops following repeated application of aluminium-containing sunscreens in children with aluminium sensitization and vaccination granulomas., Methods: Sixteen children aged 2-9 years (mean age 5 years) with vaccination granulomas and a positive patch test reaction to aluminium chloride hexahydrate 2%/10% petrolatum completed a blinded repeated open application test (ROAT) with two daily applications of two sunscreens for 14 days. One cream contained aluminium and the other did not. The children served as their own controls., Results: Sixteen children completed the study. Only one child (6%) had a positive skin reaction during ROAT on day 2 to the sunscreen with aluminium. None reacted to the sunscreen without aluminium., Conclusions: Use of aluminium-containing sunscreens may on a case basis lead to allergic contact dermatitis in aluminium allergic children., (© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

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., Competing Interests: The authors have no funding or conflicts of interest to declare., (Copyright © 2021 American Contact Dermatitis Society. All Rights Reserved.)

Background: The contact allergy prevalences in patch-tested patients are usually higher than those in the population, owing to morbidity-driven selection., Objectives: To examine the differences between two samples, one from the population, one from the patch test clinic, in one area of Germany (Jena, Thuringia)., Methods: Between August 2008 and October 2011, a total of 519 participants of the population-based european dermato-epidemiology network (EDEN) fragrance study were patch tested in Jena using a TRUE Test baseline series extended with some pet.-based (fragrance) allergen preparations. Between 2007 and 2012 (inclusive), 1906 routine patients were patch tested for suspected allergic contact dermatitis (ACD) in the Jena University Hospital Department; of these 1694 (83.2%) with the German baseline series using pet./aq.-based, investigator-loaded allergens., Results: In the population (clinical) sample, 19.6% (41.1%) were sensitized to at least one of the allergens considered. The most common baseline series allergens in the population/clinical sample were nickel (10.5%/13.2%), fragrance mix (FM) II (2.9%/6.7%), FM I (2.3%/8.3%), and cobalt (1.6%/5%). The clinical sample was slightly older (71.5% vs 55.9% age 40+) and included less males (36% vs 49.3%)., Conclusions: Results are quite similar, although prevalences are usually higher in the clinical setting, with the exception of p-tert-butylphenol formaldehyde resin., (© 2021 The Authors. Contact Dermatitis published by John Wiley & Sons Ltd.)

Abstract: Patch testing, used in the assessment of allergic contact dermatitis, is ideally avoided in patients receiving immunosuppressive therapy because of concerns with reductions in accuracy; however, this is not well characterized in the literature. This systematic review summarizes patch testing results in patients receiving immunosuppressive therapy. We identified 16 studies, comprising 195 patients with dermatitis or psoriasis, who were patch tested while receiving immunosuppressants. Of these, 7 studies, comprising 85 patients with dermatitis, patch tests were performed before and during immunosuppression. Overall, 67.9% (n = 19) of the dermatitis patients receiving dupilumab maintained positive reactions to an allergen that previously graded as a 2+/3+ reaction. Several immunosuppressants were also associated with positive patch test results for various allergens. These include dupilumab, cyclosporine, and low-dose prednisone (≤10 mg/d) for dermatitis, and tumor necrosis factor α inhibitors, ustekinumab, and methotrexate for psoriasis. Ideally, it is preferable to patch test when patients are not receiving oral immunosuppressants or immunomodulators. However, clinicians may choose to assess the risks and benefits of patch testing for each patient given the impact of allergic contact dermatitis on patient quality of life., Competing Interests: J.Y. has been a speaker, consultant, and investigator for AbbVie, Allergan, Amgen, Astellas, Boehringer Ingelheim, Celgene, Centocor, Coherus, Dermira, Eli Lilly, Forward, Galderma, GSK, Janssen, Leo, Medimmune, Merck, Novartis, Pfizer, Regeneron, Roche, Sanofi Genzyme, Takeda, UCB, Valeant, and Xenon. The other authors have no funding or conflicts of interest to declare., (Copyright © 2021 American Contact Dermatitis Society. All Rights Reserved.)

Background: Metal alloys containing contact sensitizers (nickel, palladium, titanium) are extensively used in medical devices, in particular dentistry and orthopaedic surgery. The skin patch test is used to test for metal allergy., Objective: To determine whether metal salts, when applied to freshly excised skin at patch test-relevant concentrations and using a method which mimics skin patch testing, cause in changes in the epidermis and dermis., Methods: Tissue histology, apoptosis, metabolic activity, and inflammatory cytokine release were determined for two nickel salts, two palladium salts, and four titanium salts., Results: Patch test-relevant concentrations of all metal salts caused localized cytotoxicity. This was observed as epidermis separation at the basement membrane zone, formation of vacuoles, apoptotic nuclei, decreased metabolic activity, and (pro)inflammatory cytokine release. Nickel(II) sulfate hexahydrate, nickel(II) chloride hexahydrate, titanium(IV) bis(ammonium lactato)dihydroxide, and calcium titanate were highly cytotoxic. Palladium(II) chloride, sodium tetrachloropalladate(II), titanium(IV) isopropoxide, and titanium(IV) dioxide showed mild cytotoxicity., Conclusion: The patch test in itself may be damaging to the skin of the patient being tested. These results need further verification with biopsies obtained during clinical patch testing. The future challenge is to remain above the elicitation threshold at noncytotoxic metal concentrations., (© 2021 The Authors. Contact Dermatitis published by John Wiley & Sons Ltd.)

Competing Interests: The authors have no funding or conflicts of interest to declare.

Background: Earlier laboratory studies have shown that sodium tetrachloropalladate, Myroxylon pereirae, caine mix II, and palladium chloride trigger the release of aluminium (Al) from Finn Chambers (FC)., Objectives: To investigate whether aluminium realease from FC could influence the diagnostic outcome of patch testing with FC., Method: A retrospective analysis of patch test results from 2010 to 2019 was performed. A two-sided Fisher's exact test was used to calculate any overrepresentation of contact allergy to Al among patients with positive reactions to sodium tetrachloropalladate, Myroxylon pereirae, caine mix II, and palladium chloride., Results: A total of 5446 patients had been tested with FC during the study period. There was a significant overrepresentation of contact allergy to Al among patients with positive reactions to sodium tetrachloropalladate, Myroxylon pereirae, caine mix II, and palladium chloride. Patients with a strong Al allergy had significantly higher amounts of concomitant reactions to sodium tetrachloropalladate, Myroxylon pereirae, caine mix II, and palladium chloride compared to patients with weak Al allergy. These results were not seen for patients tested with Finn Chambers AQUA., Conclusion: In patients with contact allergy to Al, patch testing with Finn chambers could give false-positive reactions to sodium tetrachloropalladate, Myroxylon pereirae, caine mix II, and palladium chloride., (© 2021 The Authors. Contact Dermatitis published by John Wiley & Sons Ltd.)

Background: Allergic contact dermatitis to metals is diagnosed by applying a metal salt in a patch test. The bioavailability of the metal salt might depend on the choice of metal salt, the concentration, sweat composition, and pH., Objectives: The main purpose of this study was to apply chemical speciation modelling, which is based on experimentally derived input data and calculates the concentrations of chemical forms (species) in solutions, to reproduce and discuss clinical patch test results of aluminium and chromium., Methods: Joint Expert Speciation System (JESS), Hydra/Medusa, and Visual MINTEQ were employed to study the bioavailable fraction and chemical form of clinically applied aluminium and chromium salts as a function of salt type, applied concentration, sweat composition, and pH., Results: Investigated aluminium and chromium salts can have a very low bioavailability with a large dependency on sweat composition, pH, metal salt, and concentration. Both aluminium and chromium ions could shift the pH towards acidic or basic values based on their chemical form., Conclusions: Reported seasonal and interpatient variability in positive reactions to aluminium is likely related to sweat pH and composition. Potassium dichromate increases the pH, whereas aluminium and trivalent chromium chloride strongly decrease the pH, possibly increasing skin diffusion., (© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Formaldehyde is an important contact sensitizer. Formaldehyde releasing substances induce positive reactions in formaldehyde-allergic patients, but there are also reactions independent of formaldehyde allergy. In an earlier study, stronger formaldehyde reactions led to more positive reactions to quaternium-15., Objectives: To analyze patterns of positive patch test reactions to formaldehyde and different formaldehyde releasers., Methods: Patch test files of 1497 patients investigated during the period November 2007-August 2020 were retrospectively reviewed for positive reactions to formaldehyde and its releasers. During the study period, almost all (≥99.3%) patients were tested with a formaldehyde dilution series and six formaldehyde releasers., Results: Ninety-three patients tested positive to formaldehyde; 80% of these had positive reactions to at least one formaldehyde releaser, most often benzylhemiformal. There were only nine independent contact allergies to formaldehyde releasers. There were only two reactions to 2-bromo-2-nitropropane-1,3-diol and they occurred in formaldehyde-negative patients. In patients with extreme (+++) reactions to formaldehyde, concomitant positive reactions to any of the other 11 investigated formaldehyde releasers were more common than in patients with milder formaldehyde reactions., Conclusions: Strong formaldehyde reactions were associated with positive reactions to formaldehyde releasers., (© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Allergic proctocolitis is a cell-dependent food allergy that is present in both breast and formula-fed infants. The presence of blood with different amounts in the stool is the main manifestation of the disease. Different results have been published on the accuracy and specificity of the atopic patch test (APT). The purpose of this study was to evaluate the results of the APT and compare them with those obtained in the food elimination/introduction (E/I) challenge, as the gold standard of confirming the allergy. Twenty-eight patients (18 boys, 10 girls, <1 year) with allergic proctocolitis were recruited in this study. The mean age of the disease onset and enrolling the study were 2.23±1.7 and 5.25±2.19 months, respectively. After performing APT with fresh foods, an E/I challenge was done in a patient with positive tests, and results were analyzed. APT was positive in 14/28 (50%) individuals. The most common foods detected by APT in all of the individuals were: milk (10/28), rice (5/28), soy (4/28), and egg white (4/28), while in E/I challenge in the APT-positive individuals were: milk (8/10), rice (3/5), egg white (1/4), and soy (0/4). APT was positive in half of the infants<1 year with allergic proctocolitis and there was no significant correlation between the APT results and the E/I challenge test for all foods. Comparing the results of APT and E/I challenge methods showed a convergence between the milk and rice sensitivity, thus we suppose APT to be a useful tool in identifying these two allergens in cell-mediated food allergies like allergic proctocolitis.

Background: Budesonide was included in the European Baseline Series in 2000 as the most suitable marker forcorticosteroid hypersensitivity. In the last two decades, a decreasing trend of budesonide allergy has been observed., Objectives: To estimate the prevalence of positive patch test reactions to budesonide in a large, Italian patch test population, characterizing patients according to MOAHLFA index and evaluating the benefit with extended readings of budesonide patch test., Methods: Retrospective analysis of patient demographics and patch test results over a 2-year period (2018-2019) was performed at 14 patch test clinics in Italy., Results: Ninety out of 14 544 (0.6%) patients reacted to budesonide 0.01% pet.. Positive reactions were mild in 54.4% and late readings at day 7 showed new positive reactions in 37.8% of patients. The MOAHLFA index showed a significant positive association with male gender, atopic dermatitis, and age >40 years and a significant negative association with hand and face dermatitis., Conclusions: We documented a low prevalence of budesonide allergy in Italy, confirming its decreasing trend recently reported in the literature. Nevertheless, budesonide needs to be maintained in the baseline series for its good ability to detect corticosteroid sensitization., (© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Sodium disulfite (SD), also known as sodium metabisulfite, is an increasingly recognized cause of allergic contact dermatitis., Objectives: The objective of this work was to characterize individuals with positive patch test reactions to SD as well as analyse reaction strength, clinical relevance, and sources., Methods: This is a retrospective analysis of patients patch tested with SD (1% petrolatum) by the North American Contact Dermatitis Group (NACDG), 2017 to 2018., Results: Of 4885 patients patch tested with SD, 132 (2.7%) had a positive reaction. Common primary anatomic sites of dermatitis were face (28.8%), hands (20.5%), and a scattered/generalized distribution (13.6%). Compared with SD-negative patients, SD-positive patients were more likely male (odds ratio 2.81, 95% confidence interval 1.98-4.00) and/or over 40 years (odds ratio 1.95, 95% confidence interval 1.30-2.94). Reactions were most commonly + (50.4%) or ++ (34.1%); 65.2% were considered currently relevant. About 15.2% were definitively confirmed in sources, commonly personal care products (18.9%, especially hair dye), and drugs/medications/alcoholic beverages (9.1%). Only 2.3% of positive reactions were linked to occupation., Conclusions: Positive reactions to SD occurred in 2.7% of tested patients. Reactions were often clinically relevant and linked to personal care products and drugs/medications/alcoholic beverages., (© 2021 John Wiley & Sons A/S . Published by John Wiley & Sons Ltd.)

Background: Because Myroxylon pereirae (MP), or balsam of Peru, is nowadays almost not used "as such," and fragrance mix 1 (FM1) apparently is more sensitive in detecting fragrance allergy, the usefulness of testing MP in baseline series was recently questioned., Objectives: Identification of the number of clinically relevant patch test reactions to MP not detected by FM1., Methods: Retrospective analysis of 12 030 patients patch tested with MP and FM1 for contact dermatitis between January 2018 and December 2019 in 13 Italian dermatology clinics., Results: Four hundred thirty-nine patients (3.6%) had a positive patch test reaction to MP; 437 (3.6%) had a positive patch test reaction to FM1. Positive reactions to both MP and FM1 were observed in 119 subjects (1.0%), 310 (2.6%) reacted to MP only, 304 (2.5%) to FM1 only, 5 to MP and sorbitan sesquioleate (SSO), 9 to FM1 and SSO, and 5 to MP, FM1, and SSO. Single sensitizations were clinically relevant in 75.2% of cases for MP (62.9% current, 12.3% past) and 76.3% for FM1 (70.1% current, 6.2% past)., Conclusions: Based on our results, MP appears to be still worth testing along with FM1 in baseline series, because it allows detection of a remarkable number of fragrance allergies, often relevant, which would be otherwise missed., (© 2021 The Authors. Contact Dermatitis published by John Wiley & Sons Ltd.)