Regulatory framework for development and marketing authorization of allergen products for diagnosis of rare type I and type IV allergies: The current status.

Development, production, and marketing authorization of allergen products is generally challenging due to several specific characteristics, including the natural source as well as the multitude of allergenic materials. Also, depending on the frequency of sensitization in the population, the number of patients available for inclusion in clinical trials can be a limiting factor for product development. In the development of allergen products for diagnosis of type I and type IV allergies these challenges are particularly demanding because, in contrast to certain products for allergen-specific immunotherapy, no exemptions from marketing authorization are foreseen for this product group in Directive 2001/83/EC. Thus, the regulatory framework is constantly adapted within the legal scope in order to balance necessary regulatory requirements ensuring quality, safety, and efficacy with the clinical need for a comprehensive range of diagnostic allergen products. In this article, we give an overview on the current regulatory framework for development and marketing authorization of allergen products for diagnosis of rare type I and type IV allergies.

Anticipating the side effects of benznidazole: HLA-B*35 and patch test.

INTRODUCTION: Treatment of Chagas disease frequently causes distress to patients due to a high incidence of adverse effects. Different preemptive tests have been researched to prevent these effects and to allow focus to be given to certain predisposed patients. Benznidazole is the most prescribed Chagas disease treatment in Spain. In this work, we analyzed the genetic markers HLA-B*35 allele group and HLA-B*35:05 allele specifically, as well as an allergy patch test, as benznidazole's most frequent adverse effects are cutaneous. METHODS: HLA-B intermediate-resolution genotyping was performed followed by a high-resolution level analysis. Cutaneous allergies were tested using strips impregnated with a mixture of benznidazole and placed on the upper back of patients before starting treatment. RESULTS: In our sample of more than 400 patients, there was almost no relationship between any kind of side effect and either of the HLA-B alleles studied. The patch testing was quickly discarded as a preemptive test due to its low sensitivity (16.7%). CONCLUSION: In conclusion, we were unable to replicate and corroborate genetic markers identified by other groups and there is currently no test that can anticipate the adverse effects of benznidazole, therefore, more investigation should be carried out in this field.

Epidemiological case-control study on contact sensitisation in female foot care specialists with occupational contact dermatitis: Patch test data of the Information Network of Departments of Dermatology (IVDK), 2008 to 2022.

BACKGROUND: Mainly women work as foot care specialists (FCS). They are at risk to develop occupational dermatitis (OD). OBJECTIVES: The objective of this study is to describe the contact sensitisation pattern of female FCS with OD. METHODS: In a retrospective study, patch test and clinical data collected by the Network of Departments of Dermatology (IVDK) from 2008 to 2022 were analysed. Data of 116 female FCS with OD were compared with data of 13 930 female patients with OD working in other professions and 78 612 female patients without OD. RESULTS: Hand dermatitis (93.1%) was significantly more common and face dermatitis (0.9%) significantly less common in female FCS with OD compared to other female patients with or without OD. Frequent suspected allergen sources were disinfectants, gloves, leave-on and nail cosmetics. Occlusion and wetness were important co-factors. The most common diagnoses were irritant contact dermatitis (26.7%) and allergic contact dermatitis (21.6%). No sensitisation to any of the baseline series allergens was significantly more frequent in female FCS with OD than in the two control groups. However, sensitisations to allergens which FCS are abundantly exposed to, including fragrances, preservatives, rubber ingredients and disinfectants, were most common. CONCLUSIONS: FCS should be aware of the OD risk and prevention should be promoted.

Contact sensitization to fragrance mix I and fragrance mix II among European dermatitis patients: A systematic review.

BACKGROUND: Fragrance substances are a frequent cause of contact allergy worldwide. Fragrance exposure varies by sex, age and possibly country, influenced by cosmetic availability, environmental conditions and cultural practices. OBJECTIVES: To systematically review and gather prevalence of sensitization to fragrance mix I (FM I) and fragrance mix II (FM II) in consecutively patch-tested European dermatitis patients. METHOD: A total of 4134 publications on patch test results of European dermatitis patients, published from 1981 to 2022, were systematically reviewed according to a previously registered and published PROSPERO protocol. RESULTS: Eighty-four eligible original articles were analysed. Overall prevalence of sensitization to fragrance mix I (FM I) was 6.81% (95% CI: 6.37-7.28), and FM II was 3.64% (95% CI: 3.3-4.01). Sensitization to FM I was most prevalent in Central and Eastern Europe and to FM II in Western Europe. No clear time trends were observed. Among paediatric dermatitis patients, sensitization prevalence for FM I and FM II was 4.09% (95% CI: 3.37-4.96) and 2.17% (95% CI: 1.53-3.07). CONCLUSION: The frequency of positive patch test results for both FMI and FMII remains high. Sensitization is also prevalent among children. Enhanced regulation and labelling of cosmetic products play a vital role in averting exposure and sensitization to fragrance allergens.

Clinical profile and photocontact sensitivity pattern in patients with cosmetic dermatitis: A prospective study.

Background With the rise in cosmetic usage, adverse reactions related to cosmetics have also risen. Photocontact dermatitis to cosmetics is a challenging entity to diagnose and manage. Objectives To evaluate the clinical features and photocontact sensitivity patterns in patients with cosmetic dermatitis and establish their association based on patch and photopatch test results. Methods A prospective observational study, where 80 patients with a clinical diagnosis of cosmetic dermatitis were patch or photopatch tested (as per indication) with the Indian standard series, Indian cosmetic and fragrance series, and the patient's personal product(s). Results A total of 104 positive reactions were observed in 57/80 patients, of which 50 were relevant to cosmetics usage. Sixty-five patients underwent a photopatch test, and 17 tested positive. Photosensitivity in patients was significantly associated with a positive photopatch test (p-value < 0.001). Various new photo-allergens were discovered, including propylene glycol, triethanolamine, chloroacetamide, isopropyl myristate, cetrimide and hexamine. Facial melanosis was a predominant clinical finding in 44 patients, with pigmented contact dermatitis detected in 19 (43.2%) of these cases. Limitations Patients' personal products could not be tested on every patient. Chemical analysis of indigenous products and the individual chemical ingredients of the patient's personal products could not be patch-tested separately. Phototesting was not performed in patients with photosensitivity. Conclusion In patients with suspected cosmetic dermatitis with history of photosensitivity or those with facial melanosis of unknown origin, a photopatch test is crucial to detect potentially hidden photo allergens. Many new photo allergens have emerged in the present study. Cosmetic companies should provide detailed information regarding each constituent of the cosmetic products.

Strategic testing following toxic epidermal necrolysis allows reintroduction of chemotherapy in a patient with progressive myeloma.

Toxic epidermal necrolysis (TEN) and Stevens-Johnson syndrome belong to a family of severe cutaneous adverse reactions that can be life-threatening and carry a risk of significant morbidity and potential mortality in the event of re-exposure. Lifelong avoidance of the culprit agent is mandated, which can lead to the exclusion of multiple medications if the trigger is unclear. This can result in adverse health outcomes analogous to that of a penicillin allergy label. We present a case in which the patient would progress to fatal myeloma in the absence of treatment, however, multiple medications were administered prior to the occurrence of TEN following previous chemotherapy. Available risk stratification tools including human leucocyte antigen assessment and the algorithm of drug causality for epidermal necrolysis scoring system were utilized followed by patch testing which identified a lesser-suspected agent as possibly causative. Further evidence-based in vivo testing and subsequent challenges allowed for the reintroduction of life-saving chemotherapy.

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.

Patch test in Brazilian children with a clinical diagnosis of atopic dermatitis: a cross-sectional study using an extended patch test battery.

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.

Contact sensitization and self-reported eczema in Swedish painters with occupational exposure to isothiazolinones.

BACKGROUND: Due to an increasing occupational usage of isothiazolinone (IT)-containing preservatives, and their potential to cause skin sensitization and allergic contact dermatitis, that is, chronic disease, there is a need for more knowledge on how highly exposed workers are affected. OBJECTIVES: The overall objective was to explore dermatological symptoms of potentially long-lasting or chronic character in Swedish painters. METHODS: Building painters from western and southern Sweden were initially invited to perform a questionnaire on occurrence of skin symptoms. Participants with affirmative responses, and the right inclusion criteria, were further invited to patch testing with four different ITs: benzisothiazolinone (BIT), methylisothiazolinone, methylchloroisothiazolinone and octylisothiazolinone. RESULTS: There was a tendency towards higher occurrence of positive patch test reactions among the painters compared with occupationally unexposed registry patients; however, not statistically significant differences. BIT was the substance most frequently causing positive test results in both groups. The occurrence of adult-onset eczema was higher in painters than in the control group of electricians, and just shy of statistical significance concerning any of several skin locations (face/legs/arms/hands). CONCLUSION: Building painters present with positive patch test reactions to common paint preservatives (ITs), and they report adult-onset eczema more often than do less occupationally exposed groups.

Severely compromised supply of patch test allergens in Europe hampers adequate diagnosis of occupational and non-occupational contact allergy. A European Society of Contact Dermatitis (ESCD), European Academy of Allergy and Clinical Immunology (EAACI), European Academy of Dermatology and Venereology (EADV) task forces 'Contact Dermatitis' and 'Occupational Skin Disease' position paper.

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.

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.

Influence of Surfactant on the Skin Permeation of Methylisothiazolinone and Methylchloroisothiazolinone.

Patch tests are often used in safety evaluations to identify the substance causing skin irritation, but the same substance can sometimes give positive or negative results depending on the test conditions. Here, we investigated differences in the skin penetration of two test compounds under different application conditions. We studied the effects of the anionic surfactant sodium dodecyl sulfate (SDS) and the nonionic surfactant polysorbate 80 (PS) on skin penetration of the preservatives methylisothiazolinone (MT) and methylchloroisothiazolinone (MCT), which are used in cosmetics such as shampoos. The skin permeation of MT was enhanced by SDS but was unchanged by PS. Skin impedance decreased in the presence of SDS whereas PS had the same effect as the control aqueous solution, suggesting that SDS reduction of the barrier function of skin affects the permeation of MT, a hydrophilic drug. Application of a mixture of MCT and MT in the presence of SDS did not affect the skin permeation of MCT whereas the permeation of MT was enhanced by SDS, indicating that the skin permeation of MCT is less affected by SDS than is MT. Thus, attention should be paid to the possible effect of co-solutes, especially hydrophilic drugs.

IgE to wheat, prick test, and Patch test among children with celiac disease.

INTRODUCTION AND AIM: Celiac disease is one of the most common autoimmune disorders. This study aimed to evaluate the relationship between celiac disease and wheat sensitization. SUBJECTS AND METHODS: In the current study, children aged < 18 years with confirmed celiac disease were included. Data were analyzed using SPSS. RESULTS: Gastrointestinal problems were the most common indication for evaluation in terms of celiac disease. Prick and patch tests were positive in 43.4% and 34% respectively. CONCLUSION: Prick test and patch test for wheat sensitization were positive in about 30-45% of the children for celiac disease.