Contact allergies to dental materials in patients.

BACKGROUND: Concerns regarding contact allergies and intolerance reactions to dental materials are widespread among patients. Development of novel dental materials and less frequent amalgam use may alter sensitization profiles in patients with possible contact allergy. OBJECTIVES: To analyse current sensitization patterns to dental materials in patients with suspected contact allergy. METHODS: This retrospective, multicentre analysis from the Information Network of Departments of Dermatology (IVDK) selected participants from 169 834 people tested in 2005-2019 and registered with (i) an affected area of 'mouth' (and 'lips'/'perioral'), (ii) with the dental material in question belonging to one of three groups (dental filling materials, oral implants or dentures or equivalents) and (iii) with patch-testing done in parallel with the German baseline series, (dental) metal series and dental technician series. RESULTS: A total of 2730 of 169 834 tested patients met the inclusion criteria. The patients were predominantly women (81.2%) aged ≥ 40 years (92.8%). The sensitization rates with confirmed allergic contact stomatitis in women (n = 444) were highest for metals (nickel 28.6%, palladium 21.4%, amalgam 10.9%), (meth)acrylates [2-hydroxyethyl methacrylate (HEMA) 4.8%] and the substances propolis (6.8%) and 'balsam of Peru' (11.4%). The most relevant acrylates were HEMA, 2-hydroxypropyl methacrylate, methyl methacrylate, ethylene glycol dimethacrylate and pentaerythritol triacrylate. Few men were diagnosed with allergic contact stomatitis (n = 68); sensitization rates in men were highest for propolis (14.9%) and amalgam (13.6%). CONCLUSIONS: Allergic contact stomatitis to dental materials is rare. Patch testing should not only focus on metals such as nickel, palladium, amalgam and gold, but also (meth)acrylates and the natural substances propolis and 'balsam of Peru'.

Identification of the pigments used in permanent makeup and their ability to elicit allergic contact dermatitis.

BACKGROUND: Decorative tattoos are known to contain ingredients that may elicit allergic contact dermatitis; it is less well-known if permanent makeup pigments carry the same risk. OBJECTIVE: Identify pigments used in permanent makeup inks sold in the United States and review cases of allergic contact dermatitis to these pigments. METHODS: Using internet searches, permanent makeup inks sold in the United States were identified. Safety data sheets were used to catalog pigments used in permanent makeup. A subsequent literature search was performed to identify cases of allergic contact dermatitis to these pigments. RESULTS: A total of 974 permanent makeup inks were reviewed, and 79 unique pigments were identified. The average product contained 4 pigments. Twenty of the pigments were inorganic metals, including carbon, iron, chromium, manganese, and molybdenum. Fifty-nine pigments were organic, of which most were azo, quinacridone, or anthraquinone dyes. A literature search revealed that 10 of the 79 pigments were associated with allergic contact dermatitis. CONCLUSION: Permanent makeup primarily uses organic pigments, although some metallic pigments are still used. Physicians should also be aware that some of these pigments-both organic and inorganic-are known causes of allergic contact dermatitis. Of note, patch testing to these ingredients can be negative.

Gene profiling in active dermatitis lesions strengthens the diagnosis of allergic contact dermatitis.

BACKGROUND: Distinguishing between allergic and nonallergic forms of Contact Dermatitis (CD) is challenging and requires investigations based on patch-testing. Early detection of allergy biomarkers in active CD lesions could refine and simplify the management of CD patients. OBJECTIVE: To characterize the molecular signatures of active CD lesions. METHODS: We studied the expression of 12 allergy biomarkers by qRT-PCR in active lesions of 38 CD patients. Allergic CD (ACD) was diagnosed based on patch test (PT) results and exposure assessment. Molecular signatures of active lesions, as well as positive PT reactions, were compared with those of reference chemical allergens and irritants. RESULTS: Nineteen of the 38 CD patients reacted positively upon patch-testing and exposure assessment confirmed ACD diagnosis for 17 of them. Gene profiling of active CD lesions revealed 2 distinct molecular patterns: patients harboring signatures similar to reference allergens (n = 23) or irritants (n = 15). Among the 23 patients with an "allergy signature," we found the 17 patients with confirmed ACD, while no culprit allergen was identified for the 6 other patients. Interestingly, the 15 patients without biomarker induction had negative PT, suggesting that they developed nonallergic CD reactions. CONCLUSION: Molecular signatures from active skin lesions may help to stratify CD patients and predict those suffering from ACD.

More than just methylisothiazolinone: Retrospective analysis of patients with isothiazolinone allergy in North America, 2017-2020.

BACKGROUND: Isothiazolinones are a common cause of allergic contact dermatitis. OBJECTIVE: To examine the prevalence of positive patch test reactions to isothiazolinones from 2017-2020 and characterize isothiazolinone-allergic (Is+) patients compared with isothiazolinone nonallergic (Is-) patients. METHODS: Retrospective cross-sectional analysis of 9028 patients patch tested to methylchloroisothiazolinone (MCI)/methylisothiazolinone (MI) 0.02% aqueous, MI 0.2% aqueous, benzisothiazolinone (BIT) 0.1% petrolatum, and/or octylisothiazolinone (OIT) 0.025% petrolatum. Prevalence, reaction strength, concurrent reactions, clinical relevance, and source of allergens were tabulated. RESULTS: In total, 21.9% (1976/9028) of patients had a positive reaction to 1 or more isothiazolinones. Positivity to MI was 14.4% (1296/9012), MCI/MI was 10.0% (903/9017), BIT was 8.6% (777/9018), and OIT was 05% (49/9028). Compared with Is-, Is+ patients were more likely to have occupational skin disease (16.5% vs 10.3%, P <.001), primary hand dermatitis (30.2% vs 19.7%, P <.001), and be >40 years (73.1% vs 61.9%, P <.001). Positive patch test reactions to >1 isothiazolinone occurred in 44.1% (871/1976) of Is+ patients. Testing solely to MCI/MI would miss 47.3% (611/1292) of MI and 60.1% (466/776) of BIT allergic reactions. LIMITATIONS: Retrospective cross-sectional study design and lack of follow-up data. CONCLUSION: Sensitization to isothiazolinones is high and concurrent sensitization to multiple isothiazolinone allergens is common.

Cost-effectiveness of patch testing allergens within the same group: A computational approach to optimize formaldehyde-related allergen selection.

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.

Contact allergy to subcutaneous implantable cardioverter defibrillator in a child with Brugada syndrome.

Allergic reactions to components of cardiac implantable electronic devices are rare and often go undiagnosed, which can lead to a misdiagnosis of device infection. Contact allergy to subcutaneous implantable cardioverter defibrillator (S-ICD) is extremely rare. In this report, we present a case of cobalt-related contact allergy in a pediatric patient with Brugada syndrome who underwent S-ICD implantation.

Fragrance Contact Allergy - A Review Focusing on Patch Testing.

Fragrance materials are widely used in various types of products in daily life and many of them can be contact sensitizers. Contact allergy to fragrances has been reported to be common worldwide. Unlike other groups of contact allergens such as metals and preservatives, fragrance materials in consumer products can be present as single fragrance chemicals or in the form of mixtures known as natural complex substances. Due to the complexity of the fragrance materials and the high number of fragrance substances known to cause contact sensitization, selecting suitable materials for patch testing is challenging. Emerging fragrance markers have been additionally introduced in different baseline series for screening to enhance the rate of fragrance contact allergy detection. Moreover, there have been continual updates on basic knowledge, clinical perspectives, sources of exposure, and regulations on the use of fragrance materials. Avoiding pitfalls while performing patch testing with fragrance test materials is also crucial and should not be overlooked. Therefore, this review aims to update knowledge to provide a high-quality holistic approach to fragrance contact allergy diagnosis and management.

Contact Allergy to Allergens in the Swedish Baseline Series Overrepresented in Diabetes Patients with Skin Reactions to Medical Devices - A Retrospective Study from Southern Sweden.

Allergic contact dermatitis is reported among individuals using continuous glucose monitoring systems and insulin pumps. The aim of this study was to describe contact allergy patterns for allergens in the Swedish baseline series and medical device-related allergens among users. Contact allergy to baseline series allergens and isobornyl acrylate was compared between diabetes patients and dermatitis patients patch-tested at the Department of Occupational and Environmental Dermatology during 2017 to 2020. Fifty- four diabetes patients and 2,567 dermatitis patients were included. The prevalence of contact allergy to fragrance mix II and sesquiterpene lactone mix was significantly higher in diabetes patients compared with dermatitis patients. Of the diabetes patients 13.0% and of the dermatitis patients 0.5% tested positive to sesquiterpene lactone mix (p < 0.001). Of the diabetes patients 7.4% and of the dermatitis patients 2.3% tested positive to fragrance mix II (p = 0.041). Of the diabetes patients 70.4% tested positive to medical device-related allergens. Of the diabetes patients 63.0% and of the dermatitis patients 0.2% were allergic to isobornyl acrylate (p < 0.001). In conclusion, not only medical device-related contact allergies, but also contact allergy to baseline series allergens (fragrance mix II and sesquiterpene lactone mix), is overrepresented in diabetes patients who use medical devices.

Comparison of outcomes of azathioprine, leflunomide and allergen avoidance in patients with patch test-positive pigmented contact dermatitis: a randomized comparative study.

BACKGROUND: Pigmented contact dermatitis (PCD) is a noneczematous form of allergic contact dermatitis characterized by dermal hyperpigmentation. Allergen avoidance is the cornerstone of therapy, but it is difficult to achieve. The use of immunosuppressives seems rational, but data are lacking. OBJECTIVES: To compare outcomes with azathioprine (AZA), leflunomide and allergen avoidance (AA) in patients with PCD. METHODS: A comparative study was conducted on 28 patients with patch test-positive PCD who were randomly allocated to one of three treatment groups: AZA 2 mg kg-1 daily for 24 weeks + AA (n = 10); leflunomide (LEF) 20 mg daily for 24 weeks + -AA (n = 8); AA alone (n = 10). Patients were followed up for an additional 24 weeks. The Dermal Pigmentation Area and Severity Index (DPASI) score and Hindi Melasma Quality of Life scale (MELASQOL) were used to assess hyperpigmentation and quality of life (QoL). respectively. RESULTS: Hair colorants (n = 12) and paraphenylenediamine (n = 8) were the most common allergens. Mean (SD) DPASI score decreased from 30.97 (3.69), 32.35 (3.90) and 31.86 (3.47) to 13.78 (4.25), 21.67 (2.99) and 20.64 (3.82) at 48 weeks in the three groups, respectively (P < 0.001); the maximum percentage decline was seen with AZA (56%). Mean (SD) MELASQOL score was reduced in the three treatment groups from 48.0 (6.46), 46.75 (3.69) and 46.6 (4.65) to 19.6 (6.98), 24.5 (5.80) and 24.0 (5.49), respectively, at 48 weeks (P < 0.001). Reductions in DPASI and Hindi MELASQOL scores were significantly correlated. The most frequent adverse event was transaminitis in both the AZA and LEF groups. CONCLUSIONS: Patients on AZA achieved a statistically significantly greater reduction in DPASI and MELASQOL score; therefore, AZA may fulfil an unmet need in PCD treatment. An objective reduction in hyperpigmentation was paralleled by an improvement in QoL score, reiterating the need for active management of this disease.

Tattoo-induced allergic contact dermatitis presents diagnostic challenge as a cellulitis mimic.

Allergic contact dermatitis (ACD) is a prevalent condition associated with numerous potential allergen exposures. Tattoo ink is variable and may contain allergens that can be overlooked in patient education and diagnosis. We present a 27-year-old female with ACD following a new tattoo. The patient was repeatedly misdiagnosed with cellulitis by three different clinicians and treated with multiple antibiotics without improvement. The correct diagnosis was eventually made in the emergency department (ED). Although the patient was aware of her allergies to nickel and cobalt from patch testing, she was not aware of the potential for tattoo ink to contain these allergens because prior tattoos had not provoked an allergic reaction. Consequently, the appropriate care was delayed by a month, resulting in significant morbidity. This case demonstrates the potential for ACD to present similarly to cellulitis in an ED setting and the need for clinical vigilance in diagnosis of ACD. It also highlights the importance of detailed patient education on potential allergen sources particularly in the context of tattooing, which is performed with unregulated and variable ink products.

Differential diagnosis of contact dermatitis: A practical-approach review by the EADV Task Force on contact dermatitis.

The diagnosis of eczema ('dermatitis') is mostly clinical and depends on the clinical history and exploratory objective findings (primary lesions, patterns). Contact dermatitis remains as an important condition in the group of eczematous disorders, with important socioeconomic and occupational relevance. Although irritant and allergic contact dermatitis have a different pathogenesis, both are characterized by a rather typical morphology, are triggered by external factors and tend to occur primarily in the area of contact with the exogenous agent. In addition, allergic and irritant dermatitis may also co-exist. The importance of diagnosing contact dermatitis, especially when allergic in nature, is both due to the possibility of avoiding the trigger, and due to its role in aggravating other skin conditions. Nevertheless, the heterogeneity of clinical presentations in daily practice may pose an important challenge for the suspicion and correct diagnosis of contact dermatitis. Furthermore, other conditions, with different pathogenesis and treatment, may clinically simulate contact dermatitis. The Task Force aims to conduct a review of the unifying clinical features of contact dermatitis and characterize its main clinical phenotypes, and its simulators, in order to contribute to an early suspicion or recognition of contact dermatitis and enable a correct differential diagnosis.

Prevalence of dermatitis including allergic contact dermatitis from medical devices used by children and adults with Type 1 diabetes mellitus: A systematic review and questionnaire study.

Use of medical devices (MDs), that is, glucose sensors and insulin pumps, in patients with Type 1 diabetes mellitus (T1D) has proven an enormous advantage for disease control. Adverse skin reactions from these MDs may however hamper compliance. The objective of this study was to systematically review and analyse studies assessing the prevalence and incidence of dermatitis, including allergic contact dermatitis (ACD) related to MDs used in patients with T1D and to compare referral routes and the clinical investigation routines between clinics being part of the European Environmental and Contact Dermatitis Research Group (EECDRG). A systematic search of PubMed, EMBASE, CINAHL and Cochrane databases of full-text studies reporting incidence and prevalence of dermatitis in persons with T1D using MDs was conducted until December 2021. The Newcastle-Ottawa Scale was used to assess study quality. The inventory performed at EECRDG clinics focused on referral routes, patient numbers and the diagnostic process. Among the 3145 screened abstracts, 39 studies fulfilled the inclusion criteria. Sixteen studies included data on children only, 14 studies were on adults and nine studies reported data on both children and adults. Participants were exposed to a broad range of devices. Skin reactions were rarely specified. It was found that both the diagnostic process and referral routes differ in different centres. Further data on the prevalence of skin reactions related to MDs in individuals with T1D is needed and particularly studies where the skin reactions are correctly diagnosed. A correct diagnosis is delayed or hampered by the fact that, at present, the actual substances within the MDs are not declared, are changed without notice and the commercially available test materials are not adequately updated. Within Europe, routines for referral should be made more standardized to improve the diagnostic procedure when investigating patients with possible ACD from MDs.

Contact allergens in African countries: A review of published patch test studies.

Only few studies on contact allergy in African countries have been published. The aim of the present study was to provide an overview of the most common contact allergens identified by the use of patch tests in African countries based on a review of the existing literature. A total of twenty-four publications from eight African countries were initially identified by search in PubMed. The abstracts and method sections were screened, and 15 studies in which patch tests were actually used to identify the allergen causing the allergic contact dermatitis (ACD) were finally selected. Nickel, cobalt, chromium, fragrance mix and p-tert-butylphenol-formaldehyde resin were the dominating contact allergens responsible for 40%-90% of the positive patch test reactions. This study indicates that a targeted effort directed towards prevention, avoidance and regulation of reliably identified contact allergens could reduce the disease burden of ACD considerable in some African countries.

The BMDC model, a performant cell-based test to assess the sensitizing potential and potency of chemicals including pre/pro-haptens.

BACKGROUND: Chemical-induced allergies at workplace represent a significant occupational health issue. These substances must be properly identified as sensitizers. In previous studies, an original model using mouse bone marrow-derived dendritic cells (BMDC) was developed for this purpose. OBJECTIVES: The aim of this study was to evaluate the predictive capacity of the BMDC model with a large panel of sensitizers (including pre- and pro-haptens) and non-sensitizers. METHODS: The readout from the BMDC model is based on expression levels of six phenotypic markers measured by flow cytometry. RESULTS: The results indicate that 29 of the 37 non-sensitizers, and 81 of the 86 sensitizers were correctly classified compared to the Local Lymph Node Assay (LLNA). Statistical analysis revealed the BMDC model to have a sensitivity of 94%, a specificity of 78%, and an accuracy of 89%. The EC2 (Effective Concentration) values calculated with this model allow sensitizers to be categorized into four classes: extreme, strong, moderate and weak. CONCLUSIONS: These excellent predictive performances show that the BMDC model discriminates between sensitizers and non-sensitizers with outstanding precision equal to or better than existing validated alternative models. Moreover, this model allows to predict sensitization potency of chemicals. The BMDC test could therefore be proposed as an additional tool to assess the sensitizing potential and potency of chemicals.

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.

Clinical relevance of doubtful reactions in patch testing: A single-centre retrospective study.

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.

Contact allergy to SIDAPA baseline series allergens in patients with eyelid dermatitis: An Italian multicentre study.

BACKGROUND: Eyelid dermatitis is a frequent reason of dermatological consultation. Its aetiology is not univocal, being contact dermatitis, both allergic and irritant, the most frequent. The primary sources of allergen exposure include cosmetics, metals, and topical medications, from direct, indirect, or airborne contact. OBJECTIVES: To define the frequency of positive patch test reactions to SIDAPA baseline series allergens, to document positive allergens, and to precise the final diagnosis in patients with eyelid involvement. METHODS: A total of 8557 consecutive patients from 12 Italian Dermatology Clinics underwent patch testing with SIDAPA baseline series in 2018 and 2019. Patients were divided into two groups: (i) with eyelid involvement with or without other involved sites (E-Group) and (ii) without eyelid involvement (NE-Group). The final diagnosis and the frequency of positive relevant patch test reactions were evaluated. RESULTS: E-Group consisted of 688 patients (females 78.6%, mean age 45.3 years), 8.0% of 8557 consecutively patch-tested patients. The final diagnosis in E-Group was ADC in 42.4%, ICD in 34.2%, and AD in 30.5%. The highest reaction rates were elicited by nickel sulphate and methylchloroisothiazolinone/methylisothiazolinone in both E-Group and NE-Group, even if these allergens were significantly more frequently positive in NE-Group patients than in E-Group ones. Positive patch test reactions to fragrance Mix II, dimethylaminopropylamine, and sorbitan sesquiolate were significantly more frequent in E-Group patients than in NE-Group ones. CONCLUSIONS: Eyelid dermatitis is a frequent dermatological complaint. Allergic contact dermatitis is the most frequent diagnosis commonly caused by nickel sulphate, isothiazolinones, and fragrances. The surfactants dimethylaminopropylamine and sorbitan sesquioleate are emerging causes of eyelid allergic contact dermatitis.

Comparison of patch test positivity after 24 and 48 hours of occlusion time in patients of allergic contact dermatitis: A prospective study.

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.

Diagnosing contact dermatitis using machine learning: A review.

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.

Potassium dichromate sensitivity presenting as tefillin dermatitis: A retrospective cohort study.

BACKGROUND: Tefillin are a religious article worn by Jewish men during daily prayer. Tefillin dermatitis secondary to potassium dichromate sensitivity is recognised, but data remain sparse. OBJECTIVE: To investigate the prevalence and clinical characteristics of tefillin dermatitis. METHODS: Patients who underwent patch testing with the European baseline series in a tertiary dermatology clinic in 2009-2023 and were diagnosed with tefillin dermatitis were identified by file review and their clinical data recorded. RESULTS: Of 1679 consecutive male patients tested, 25 (1.49%) were diagnosed with tefillin dermatitis, accounting for 15.34% of all potassium-dichromate-positive patients (163/1679). Mean pre-symptomatic duration of tefillin use was 38 ± 16.9 years, and mean follow-up time, 3.1 ± 2.9 years. Patients presented with an eczematous rash on body areas in direct contact with the leather box or straps of the tefillin. An id reaction was noted in 32%, and sensitivity to other leather accessories, in 44%. Fourteen patients (56%) switched to chromate-free tefillin: symptoms resolved completely in 11 (79%) and partially in 2. LIMITATIONS: Retrospective cohort design. CONCLUSION: This is the largest study to date of tefillin dermatitis caused by sensitivity to potassium dichromate used in leather production. Prognosis after switching to chromate-free tefillin was good-to-excellent. Tefillin dermatitis may be more prevalent than previously thought.