Patch Test Research Articles

Perfil epidemiológico, clínico y alérgico en pacientes con psoriasis. Evaluación del Registro Español de Dermatitis de Contacto (REIDAC)

BackgroundPsoriasis is a chronic inflammatory dermatosis whose clinical and topographic distribution requires differential diagnosis, or the possible association with allergic contact dermatitis (ACD), requiring patch testing (PT) as part of the diagnostic procedure. ObjectivesTo describe the epidemiological, clinical, and allergic profile of patients with a primary or secondary diagnosis of psoriasis undergoing PT and compare them with patients with a diagnosis of ACD at the end of the diagnostic process. MethodsCross-sectional study with data from REIDAC from 2018 through 2023 of selected patients with a diagnosis of psoriasis and/or ACD. ResultsA total of 11 502 patients were included, 513 of whom had been diagnosed with primary or secondary psoriasis, 3640 with ACD, and 108 with both diseases. Men were more predominant in the groups of patients with psoriasis, psoriasis+ACD, and lesions were more predominantly seen in the hands with little association with atopic factors vs the ACD group. The rate of positivity in PT to the 2022 Spanish battery of allergens was lower in the group with psoriasis only in 27% of the patients. The most common allergens found in the psoriasis group were also the most common ones found in the overall ACD population. ConclusionsOverall, 36.2% of psoriatic patients tested positive in PT to the 2022 Spanish battery of allergens, which proved that this association is not uncommon. Overall, psoriatic patients had a higher mean age, were more predominantly men, and showed more hand involvement.

Pigmented contact dermatitis: An updated review

Pigmented contact dermatitis (PCD) is a disorder brought on by repeated exposure to low-intensity allergens, usually presenting as blotchy or reticulate slate-gray pigmentation affecting Fitzpatrick skin type IV-VI. The pathogenesis remains unclear; however, type IV hypersensitivity reactions due to allergic sensitization, genetics, ultraviolet exposure, and autoimmunity are to blame. Clinical examination, dermoscopy, patch/photo patch testing, histopathology, and recently, a novel reflectance confocal microscopy and multimodality skin imaging system aid in the diagnosis. Several contact allergens have been linked to PCD, but from an Indian perspective, Kumkum and Paraphenylenediamine are the incriminating agents. Patch testing plays an immense role whenever PCD is diagnosed, primarily due to contact allergens. Devastating psychological impacts can result from PCD-related deformity on social acceptance, mental health, and self-esteem. Avoiding allergens, wearing broad-spectrum sunscreen, and engaging in sun-protective behavior are general measures for treating the condition.

Is Food-Triggered Atopic Dermatitis a Form of Systemic Contact Dermatitis?

Food allergy in atopic dermatitis is mediated by complex immune interactions between genetics, diet, environment, and the microbiome. When contact between inflamed skin and food antigens occurs, contact hypersensitivity can develop. Consequently, systemic contact dermatitis (SCD) can occur after ingestion of allergenic foods or food additives in the setting of a Th2 response with CLA-positive T cells, triggering dermatitis where skin resident memory lymphocytes reside. This phenomenon explains food-triggered dermatitis. Atopy patch tests (APTs) detect sensitization to food proteins responsible for SCD, which in turn can be confirmed by oral food challenge with delayed interpretation. We summarize the literature on using APTs to identify foods for oral challenge with dermatitis as an outcome. In dermatitis patients at risk for Th2 skewing based on a history of childhood-onset flexural dermatitis, shared decision-making should include a discussion of identifying and avoiding food and food additive triggers, as well as identifying and avoiding all contact allergens, prior to initiation of systemic therapy for dermatitis.

Regulation of immune response genes in the skin of allergic and clinically tolerant individuals exposed to p-phenylenediamine.

p-Phenylenediamine (PPD) is a potent contact allergen found in many hair colour products. However, not all individuals develop allergic contact dermatitis (ACD) although they are regularly exposed to PPD. It is unclear whether these asymptomatic individuals are true non-responders to PPD or whether they mount a response to PPD without showing any symptoms. Skin biopsies were collected from 11 asymptomatic hairdressers regularly exposed to PPD and from 10 individuals with known ACD on day 4 after patch testing with 1% PPD in petrolatum and petrolatum exclusively as control. RNA sequencing and confocal microscopy were performed. T cell activation, inflammation and apoptosis pathways were up-regulated by PPD in both asymptomatic and allergic individuals. Compared to asymptomatic individuals with a negative patch test, individuals with a strong reaction to PPD strongly up-regulated both pro- and anti-inflammatory cytokines genes. Interestingly, PPD treatment induced significant up-regulation of several genes for chemokines, classical type 2 dendritic cell markers and regulatory T cell markers in both asymptomatic and allergic individuals. In addition, apoptosis signalling pathway was activated in both non-responders and allergic individuals. This study demonstrates that there are no true non-responders to PPD but that the immune response elicited by PPD differs between individuals and can lead to either tolerance, subclinical inflammation or allergy.

Correlation of photopatch positivity with clinical profile in patients with photoallergic dermatitis

Photopatch test (PPT) is designed to diagnose Photoallergic Contact Dermatitis (PACD) using specific dose and wavelength of irradiation. This study is a retrospective analysis of patients with photosensitivity who have undergone photopatch testing. To find the Correlation of photo patch positivity with clinical profile in patients with photoallergic dermatitis. Photo patch testing helps in determining the sensitizing potentials of commonly used day to day agents containing the allergen. Thirty-seven patients who had patch tested between July 2022and June 2023 were analyzed. The patch test antigens comprising 20 common photoallergens from Indian Standard Series were photopatch tested. Of all the patients tested the overall positivity rate was (67.56%). All patients had a characteristic clinical picture of photodermatitis for an variable duration. All patients were engaged in various occupations that involved working outdoors. The exacerbating factors were summer season in 15 (40.54%) patients, insecticides spraying in three (8.1%) and exposure to plant in ten (27%). History of contact with cement was present in six (16.21%) patients. The patients who showed positivity after irradiation was 5 (13.51 %), before and after irradiation was 7 (18.91%), and exacerbated grading after irradiation was 13 (35.13%). The commom allergen showing positivity were parthenium (29.72%), potassium dichromate (13.51%), PPD (10.81%). Apart from these allergens’ fragrance mix, paraben, neomycin sensitivity was also noted in few patients. Significant number of cases belongs to photodermatitis, thereby, finding the cause and the measures to alleviate the symptoms are paramount important. For proper diagnosis, photopatch test is essential and our study emphasis the same which can aid in appropriate management. Cosmetics, sunscreens and drugs like NSAID are found to be the emerging cause for PACD and photopatch series with relevence to above allergen is the need of the hour.

A clinico-epidemiological study of breast eczema sparing nipple and areola from a tertiary care hospital in western Rajasthan

Nipple eczema can be a local manifestation of atopic dermatitis/eczema when it arises with classic age-related patterns of eczema on other body sites, or it can occur in isolation. In our study, breast eczema sparing nipple and areola, was observed in females of western Rajasthan. This study reports the demography, clinico-morphological patterns and factors causing it. After due informed consent, thirty consecutive female patients of breast eczema were undergone a detailed history, clinical examination and patch testing. Hamilton Anxiety Rating Scale was used for anxiety severity assessment. Most common site of breast eczema was the upper-outer quadrant (15/30) followed by upper-inner quadrant (9/30). The cell-phone was the most common object which was kept in close contact with the breast followed by purse (26/30) and money (11/30). Total 20 positive patch tests were seen in 17 patients. Fifteen patch tests were relevant to the current dermatitis. Mild anxiety cases were significantly more in acute type whereas moderate-severe type was more with chronic type (p value=0.021). Larger study is required to establish the exact cause of this type of breast eczema. Breast eczema seems to have diverse etiology, supplemented by various factors such as anxiety, perspiration in hot arid weather, traditional loosely-fit inner clothing of women in this region of western Rajasthan and friction produced by the objects (cell phones) that are kept in contact with breasts, work together to produce dermatitis.

Metal allergy and neurovascular stenting: A systematic review.

Intracranial stents and flow diverters contain significant amounts of metals, notably nickel, which can cause allergic reactions in a considerable portion of the population. These allergic responses may lead to complications like in-stent stenosis (ISS) and TIA/Stroke in patients receiving stents or flow diverters for intracranial aneurysms. We conducted a systematic review of studies from inception until July 2023, which reported outcomes of patients with metal allergy undergoing neurovascular stenting. The skin patch test was used to group patients into those with positive, negative, or absent patch test results but with a known history of metal allergy. Our review included seven studies with a total of 39 patients. Among them, 87% had a history of metal allergy before treatment. Most aneurysms (89%) were in the anterior circulation and the rest (11%) were in the posterior circulation. Skin patch tests were performed in 59% of patients, with 24% showing positive results and 33% negative. Incidental ISS was observed in 18% of patients, and the rate of TIA/Stroke was reported in 21%. The pooled rates of ISS and TIA/Stroke were higher in the first group (43% and 38%) compared to the second (18% and 9%) and third groups (15% and 15%), but these differences were not statistically significant. The current neurosurgical literature does not provide a conclusive association between metal allergy and increased complications among patients undergoing neurovascular stenting. Further studies are necessary to gain a more comprehensive understanding of this topic.

Exploring the relationship between allergic contact dermatitis and atopic dermatitis in children: insights from a retrospective patch testing analysis.

Recent years have seen significant exploration into the potential link between allergic contact dermatitis and atopic dermatitis, yielding contradictory findings. A retrospective cohort analysis of children aged 2 to 18 who underwent patch testing at the pediatric dermatology clinic at a tertiary medical center in Israel was conducted. Overall, 367 patients were included in the study, 31.6% of whom were diagnosed with atopic dermatitis. 160 children (43.6%) exhibited a positive reaction to at least one compound in the European baseline series. There was no statistically significant difference in reactivity between children with atopic dermatitis and those without (P = 0.848). Sub-analyses based on ethnicity, gender, and age did not reveal significant differences in overall European baseline series reactivity (P = 0.612, P = 0.446, P = 0.488, respectively). Sensitivity was notably higher when patch readings were conducted 72 h after application compared to 48 h [0.95 (CI: 0.91-0.97) vs. 0.60 (CI: 0.55-0.66)]. Patch testing is imperative for suspected cases of allergic contact dermatitis in all children, regardless of their atopic background. Further research is warranted to potentially replace the traditional 48-h reading with a single 72-h reading in future guidelines, contributing to enhanced efficiency and cost-effectiveness in clinical practice.

Diagnostic gap due to missing patch test allergens—status quo and possible scenarios for mitigation

SummaryAccording to European Directive 2001/83/EC, test and therapeutic allergens are medicinal products in all Member States of the European Union. This applies equally to prick test and to patch test (PT) allergens (haptens). All test allergens commercially marketed in Germany are finished medicinal products requiring marketing authorization (MA). Currently, 211 PT substances are authorized in Germany, and an additional 59 are in an ongoing MA process and are marketable under a transitional provision until a decision on MA is made. The regulatory guidance (CMDh/399/2019) of the Co-ordination Group for Mutual Recognition and Decentralized Procedures—Human (CMDh), published in July 2020, specifies the regulatory requirements for different allergen products. Due to differences in origin and exposure, use, mode of action, and safety risks, the guideline clearly differentiates between products with active ingredients of biological origin (allergen extracts from natural source materials) and products with active ingredients of non-biological origin (hapten-based PT substances). Currently, guideline-compliant patch testing is hampered by the lack of numerous commercial PT allergens from the standard and special test series. Background and possible scenarios for mitigation are presented here.

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

BackgroundDistinguishing between allergic and non-allergic 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. ObjectiveTo characterize the molecular signatures of active CD lesions. MethodsWe 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. Results19 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 two 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 non-allergic CD reactions. ConclusionMolecular signatures from active skin lesions may help to stratify CD patients and predict those suffering from allergic contact dermatitis.

Mild but effective skin cleansing-Evaluation of laureth-23 as a primary surfactant.

Skin cleansing products are among the main reasons for the development of hand eczema. Therefore, a mild but effective skin cleansing product is of particular interest, especially in the work place, where various contaminations frequently have to be removed from hands. In this study, the potential of laureth-23 as a primary surfactant was evaluated and compared to other fatty alcohol ethoxylates (FAEO). Also, different laureth-23 surfactant combinations were compared to each other. Therefore, transepidermal water loss, erythema and visual scoring were measured after occlusive patch testing in 24 healthy subjects (aged 18-55). Afterwards, the results were ranked from low to high irritant potential and an irritation score was calculated. Furthermore, the cleaning performance was tested using an automated cleansing device in 10 healthy subjects (aged 18-55). The results confirmed the low irritant potential of laureth-23 and blends thereof. Within the different laureth-23 surfactant combinations, the combination of laureth-23 with a mild amphoteric and a mild anionic surfactant was superior to other laureth-23 surfactant combinations like laureth-23/anionic/anionic regarding skin compatibility as well as cleaning performance. In conclusion, laureth-23 showed very good performance as a primary surfactant. Especially, the combination of laureth-23, cocamidopropyl betaine and disodium laureth sulfosuccinate was mild to the skin while also showing good cleansing performance.

Titanium Allergy: A Retrospective Review of 166 Patch Tested Patients.

Background: Although most patients do not develop hypersensitivity reactions to metals in implanted devices, when they do occur, significant morbidity can result. Titanium-based systems are often considered as an alternative option in metal-allergic patients; however, there are few studies published on titanium allergy and allergic reactions to titanium in implants may be overlooked in clinical practice. Methods: Our aim was to further characterize a single institution's experience with titanium patch testing and evaluation of titanium allergy. We performed a retrospective medical record review of 166 patients evaluated for titanium contact allergy between January 2018-August 2023. Of the 166 patients in our cohort, 67 were referred for pre-implant patch testing and 64 for post-implant patch testing; 35 were tested for reasons unrelated to an implant. Results: Twenty-six of the 166 patients were PTP to titanium (15.7% positive rate). Titanium PTP rates were higher for post-implant cases (28.1%, 18/64) compared to pre-implant cases (6.0%, 4/67) (χ2 9.97, p = 0.002). Among 18 titanium PTPs identified for the 64 post-implant cases, 8 were likely relevant, 8 possibly relevant, and 2 not likely relevant. Conclusions: Further studies should be performed to evaluate the incidence of allergy to titanium implants and to continue surveillance of changes in sensitization rates.

Overcoming False-Negative Patch Tests: A Systematic Literature Review.

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.

Patch Test in Chronic Urticaria as a Diagnostic Investigative Tool – A Study in a Tertiary Care Center

Abstract Background: Chronic urticaria (CU) is associated with diverse clinical presentations and varied etiology. Contact allergy plays a critical role in the etiopathogenesis of CU; thus, a patch test can be helpful in identifying potential contact allergens. Aims and Objectives: The aim and objective of this study were to study the causative contact allergen in CU using the Indian Standard Battery allergens approved by the Contact and Occupational Dermatoses Forum of India and to establish the use of patch test in CU. Materials and Methods: One hundred clinically diagnosed cases of CU patients attended to the dermatology department for 2 years were evaluated with detailed history and clinical examination and a patch test was done using the Indian standard series. The patches were removed after 48 h and a reading was taken after 30 min. Observations were graded according to the International Contact Dermatitis Research Group recommendations. Results: Hospital-based prevalence of CU among patients attending the dermatology outpatient department was 3%. A positive patch test was observed in 30% of our study cases. Nickel sulfate was the most common allergen followed by fragrance mix. Patch test positivity was more in housewives, followed by farmers, teachers, and construction workers. Conclusion: The patch test can be used as a diagnostic investigative tool for the etiological diagnosis of CU.

Patch testing in occupational dermatology: Practical aspects in relation to the conditions in Germany.

Allergic contact dermatitis is one of the most frequent occupational skin diseases. Targeted allergen avoidance can only be achieved by identification of the causative allergen. Therefore, patch testing is of utmost importance in occupational dermatology, not only in terms of assessing causal relationships but also regarding the implementation of prevention measures and evaluation of the legal criteria for an occupational skin disease in Germany (statutory occupational disease BK 5101). The lack of commercial patch test preparations poses a great diagnostic challenge. Patch testing of patient's own materials from their workplace is therefore very important to reduce diagnostic gaps. The performance and documentation of the patch test should be in line with current guidelines and recommendations to ensure the necessary test quality and comprehensibility of the test results.

Role of Patch Testing in Facial Contact Dermatitis: A Cross-Sectional Study from Central India.

Facial contact dermatitis is an emerging skin disorder due to the use of a large array of materials over the face. It leads to psychological distress in patients, impacting their quality of life. Most of the allergens applied over the face vary as per cosmetic or herbal products' availability, usage, or religious practices. Identifying and discontinuing the implicated allergens will lead to a better prognosis and reduced morbidity in clinical practice. To determine the frequency of different allergens responsible for causing facial contact dermatitis, in an urban part of central India, using patch test with the help of Indian standard and cosmetic series. All suspected patients (>18 years) of facial contact dermatitis visiting the outpatient department of dermatology were patch tested with both Indian standard and cosmetic series. Out of 38/58 patch-test-positive patients, 71.06% were females, and 28.94% were males. Most patch-test-positive females were housewives. The most common allergens implicated were thiomersal (17.24%), followed by fragrance mix (15.51%), and paraphenylene diamine (12.06%). In our study, forehead and malar areas were most commonly involved indicating fairness creams and perfumes as the important contributors to facial contact dermatitis. Antigen batteries need to be updated with changing social and cultural trends, as many with a consistent history of aggravation with some products tested negative in patch tests.

Contact sensitization in pediatric patients with atopic dermatitis: a purpose for a new patch testing series for the Portuguese population.

Background. Atopic dermatitis is a prevalent condition in the pediatric population, with affected children exhibiting a susceptibility to cutaneous sensitization due to skin barrier dysfunction and immune dysregulation. Recent studies have highlighted an increased prevalence of certain allergens, which identifi-cation may be clinically relevant, with direct implications for the management of atopic dermatitis. Methods. We retrospective reviewed pediatric patients patch tested due to suspected contact dermatitis. Patients were divided according the diagnosis of AD, with subsequent comparison of positive results for both groups. Results. A total of 145 pediatric patch testing were analyzed, 44.1% (n = 63) with the diagnosis of atopic dermatitis. There were notable differences in sensitization rates of relevant allergens between groups and when compared to other European studies. Based on the most prevalent and relevant allergens, we proposed an adapted hapten series for assessing portuguese pediatric patients with AD and suspicion of concomitant allergic contact dermatitis. Conclusions. Our findings confirmed the geograph-ic sensitization variability and emphasize the need for pediatric adaptation and "individualized baseline series".

Putative pseudolysogeny-dependent phage gene implicated in the superinfection resistance of Cutibacterium acnes.

Objectives: Cutibacterium acnes, formerly Propionibacterium acnes, is a bacterial species characterized by tenacious acne-contributing pathogenic strains. Therefore, bacteriophage therapy has become an attractive treatment route to circumvent issues such as evolved bacterial antibiotic resistance. However, medical and commercial use of phage therapy for C. acnes has been elusive, necessitating ongoing exploration of phage characteristics that confer bactericidal capacity. Methods: A novel phage (Aquarius) was isolated and analyzed. Testing included genomic sequencing and annotation, electron microscopy, patch testing, reinfection assays, and qPCR to confirm pseudolysogeny and putative superinfection exclusion (SIE) protein expression. Results: Given a superinfection-resistant phenotype was observed, reinfection assays and patch tests were performed, which confirmed the re-cultured bacteria were resistant to superinfection. Subsequent qPCR indicated pseudolysogeny was a concomitantly present phenomenon. Phage genomic analysis identified the presence of a conserved gene (gp41) with a product containing Ltp family-like protein signatures which may contribute to phage-mediated bacterial superinfection resistance (SIR) in a pseudolysogeny-dependent manner. qPCR was performed to analyze and roughly quantify gp41 activity, and mRNA expression was high during infection, implicating a role for the protein during the phage life cycle. Conclusions: This study confirms that C. acnes bacteria are capable of harboring phage pseudolysogens and suggests that this phenomenon plays a role in bacterial SIR. This mechanism may be conferred by the expression of phage proteins while the phage persists within the host in the pseudolysogenic state. This parameter must be considered in future endeavors for efficacious application of C. acnes phage-based therapeutics.

Axillary Contact Dermatitis: An Update on Potential Allergens and Management.

The differential diagnosis of dermatoses in the axillae is broad. Contact dermatitis-both irritant and allergic-represents common etiologies. Axillary contact dermatitis can develop following exposure to a variety of irritants and/or allergens. Frequently implicated sources include deodorants, antiperspirants, detergents, soaps, and clothing. Fragrance, a ubiquitous ingredient within these products, as well as metals and dyes, are common causes of contact dermatitis. Clinical assessment, bedside diagnostic techniques, histopathology, and patch testing can aid in the diagnosis and help inform management directions.

Predictive factors of polysensitization to contact allergens: study conducted at the Dermato-Allergology Unit of the Farhat Hached University Hospital in Sousse, Tunisia

polysensitization is often defined as sensitization to three or more contact allergens. The objectives of our study were to determine the prevalence of polysensitization to allergens patch test and to analyze the factors associated with allergen polysensitization of the European Standard Battery in comparison with cases of oligosensitization. this is a retrospective descriptive cross-sectional study that included all patients who had undergone patch tests at the Department of Dermato-Allergology of the Department of Occupational Medicine of University Hospital Center Farhat Hached in Sousse spread over 10 years from January 1, 2009 to December 31, 2018. in total, we collected 464 cases of contact dermatitis during the study period. The average age of patients was 38.93 ± 12.52 years with a slight female predominance (52.8% of cases). Among all the patients who consulted during the study period (832 patients), 133 patients had positive reactions to 3 or more allergens 16% of patients. Concerning, the associations of the most frequently noted allergens were those of triplet (chromium, cobalt, and nickel) in 15 patients and triplet (mercaptobenzothiazole, thiuram mix, and IPPD) in 7 cases. The predictive factors of polysensitivity were the personal history of leg ulcers; the site of the lesions in the thorax and the erythematous squamous and dyshidrotic appearance of the lesions. this phenomenon is frequent polysensitization, and close collaboration between dermatologists and occupational physicians to prevent this type of multiple allergies through better management of personal and also professional risk factors.