Sesquiterpene Lactone Mix Research Articles

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.

Trends in contact sensitization, results, and implications from a contact dermatitis clinic in Israel.

The baseline series includes common allergens, evolves over time, and differs by location. Our study aims to characterize allergen sensitization trends among the Israeli population during the last two decades, compare our results to American and European registries, as well as to highlight significant allergens in additional series outside the European baseline series (OEBS). We analysed patch test results of 2086 patients from a designated contact dermatitis clinic in Tel Aviv between 2019 and 2022, compared them to European and North American registries and to 2156 patch test results conducted in Israel two decades ago. 38.6% of patients had at least one positive reaction to an allergen in the European baseline series (EBS), nickel sulphate (14.6%), fragrance mix I (4.6%), and Methylchloroisothiazolinone methylisothiazolinone (MCI/MI; 3.7%) were the most common among them. N-Isopropyl N-Phenyl-4-Phenylenediamine (NIPPD; 0%), Propolis (0.1%), Sesquiterpene lactone mix (0.1%), and Budesonide (0.1%) elicited a sensitization frequency significantly lower than the proposed threshold for baseline inclusion. Chi-square test revealed a statistically significant decrease (p < 0.05) in the sensitization frequency of fragrance mix I, Formaldehyde, Potassium dichromate, Neomycin sulphate, Myroxylon pereirae, Sesquiterpene lactone, and NIPPD during the last two decades. The overall sensitization frequency to the majority of allergens was lower in our cohort in comparison to the North American and European registries. MCI/MI and 2-hydroxyethyl methacrylate-2 (HEMA) are common, relevant allergens, with high SPIN (significance and prevalence index number) and should be better regulated by the authorities. While among the EBS, NIPPD, Propolis, Sesquiterpene lactone, and Budesonide usually do not elicit a positive reaction and therefore should be reconsidered in baseline series, among the OEBS, Chloramphenicol, Quaternium 15, Propyl gallate, and Amerchol L101 have elicited high SPIN values and should be vigilantly examined in the suitable clinical scenario. Significantly lower sensitization frequency to propolis raises the possibility of a protective effect due to early oral exposure among the Israeli population.

The sesquiterpene lactone mix: A review of past, present and future aspects.

The sesquiterpene lactones (SLs) are secondary plant metabolites, which are widespread in the Compositae/Asteraceae plant family. The first SLs were detected more than 100 years ago, and allergic contact dermatitis from Compositae has been reported since the beginning of the 1900s, but it was not until the late 1960s and early 1970s that a collaboration between dermatologists, chemists and botanists led to the detection of SLs as the main allergens of Compositae plants. In the 1980s, the SL mix, consisting of equimolar amounts of alantolactone, costunolide and dehydrocostus lactone, was developed as a screening agent for Compositae sensitisation. Today, after inclusion of SL mix in the baseline series, the mean prevalence of reactions in Europe is around 1%, and in North America 0.8%. In countries outside Europe and North America, the prevalence ranges between 0% and 10.7%. The detection rate of SL mix is lower than that of some plant extracts, and ideally, SL mix should be supplemented with a mix of SLs from locally prevalent allergenic plants. The prevalence of positive reactions to SL mix suggests continued baseline testing in most European countries, North America, New Zealand, Australia and probably some Chinese centres.

P75 Are ‘hypoallergenic’ personal care products truly safe?

Abstract It is estimated that one-fifth of the general population may have allergic contact dermatitis (ACD) to common environmental allergens. Skincare companies are increasingly advertising their products as ‘hypoallergenic’, targeting consumers who seek personal care products (PCPs) that are less likely to cause an allergic reaction. However, there are no Food and Drug Administration standards to regulate the use of the term hypoallergenic, allowing manufacturers to use the term freely. We evaluated PCPs marketed as hypoallergenic from two health and beauty retailers in the UK for the presence of allergens in the British Society of Cutaneous Allergy (BSCA) baseline series. Product and ingredient lists were obtained from www.boots.com and www.superdrug.com in November 2022 using the term hypoallergenic in the search box. PCPs without the term hypoallergenic in the product description, unrelated products (plasters, jewellery, sanitary towels, tampons, clothing, facial brushes) and duplicates (same products in different sizes) were excluded. In total, 208 PCPs met the inclusion criteria: 47 (22.6%) were rinse-off and 161 (77.4%) were leave-on products. At least one substance from the BSCA baseline series was an ingredient in 79 (38.0%) PCPs. Of these, 54 (26.0%) had 1 potential allergen, 21 (10.2%) had 2, and 4 (1.9%) had 3 potential allergens from the series. The frequently encountered allergens were cetearyl alcohol and paraben mix, found in 42 (20.4%) and 37 (18.0%) of products, respectively. Other BSCA baseline series allergens identified in PCPs included 2-bromo-2-nitropropane-1,3-diol, lanolin, decyl glucoside, diazolidinyl urea, methylisothiazolinone, limonene and linalool. In addition, PCPs had chemicals that were related to and may cross-react with allergens in the BSCA baseline series. Parfum/fragrance, which can cross-react with fragrance mix I and II, was found in 85 (41.3%) PCPs. Sodium benzoate and/or benzoic acid, often used as preservatives in PCPs, were found in 66 (32.0%) products. Forty (19.4%) PCPs had ingredients that belong to the Asteraceae family and therefore may trigger an ACD in those with positive reaction to Compositae and/or sesquiterpene lactone mix. Twenty-three (11.2%) PCPs contained cetyl alcohol and/or stearyl alcohol, the two major components of cetearyl alcohol. Overall, 153 (74.3%) of 206 PCPs marketed as hypoallergenic contained BSCA baseline series allergens or ingredients that may cross-react with them. This highlights the need to increase public awareness and education about the potential dangers of purchasing ‘hypoallergenic’ PCPs.

CD10 (P75) Are ‘hypoallergenic’ personal care products truly safe?

Abstract It is estimated that one-fifth of the general population may have allergic contact dermatitis (ACD) to common environmental allergens. Skincare companies are increasingly advertising their products as ‘hypoallergenic’, targeting consumers who seek personal care products (PCPs) that are less likely to cause an allergic reaction. However, there are no Food and Drug Administration standards to regulate the use of the term hypoallergenic, allowing manufacturers to use the term freely. We evaluated PCPs marketed as hypoallergenic from two health and beauty retailers in the UK for the presence of allergens in the British Society of Cutaneous Allergy (BSCA) baseline series. Product and ingredient lists were obtained from www.boots.com and www.superdrug.com in November 2022 using the term hypoallergenic in the search box. PCPs without the term hypoallergenic in the product description, unrelated products (plasters, jewellery, sanitary towels, tampons, clothing and facial brushes) and duplicates (same products in different sizes) were excluded. In total, 208 PCPs met the inclusion criteria: 47 (22.6%) were rinse-off and 161 (77.4%) were leave-on products. At least one substance from the BSCA baseline series was an ingredient in 79 (38.0%) PCPs. Of these, 54 (26.0%) had one potential allergen, 21 (10.2%) had two, and four (1.9%) had three potential allergens from the series. The frequently encountered allergens were cetearyl alcohol and paraben mix, found in 42 (20.4%) and 37 (18.0%) of products, respectively. Other BSCA baseline series allergens identified in PCPs included 2-bromo-2-nitropropane-1,3-diol, lanolin, decyl glucoside, diazolidinyl urea, methylisothiazolinone, limonene and linalool. In addition, PCPs had chemicals that were related to and may cross-react with allergens in the BSCA baseline series. Parfum/fragrance, which can crossreact with fragrance mix I and II, was found in 85 (41.3%) PCPs. Sodium benzoate and/or benzoic acid, often used as preservatives in PCPs, were found in 66 (32.0%) products. Forty (19.4%) PCPs had ingredients that belong to the Asteraceae family and therefore may trigger an ACD in those with positive reaction to Compositae and/or sesquiterpene lactone mix. Twenty-three (11.2%) PCPs contained cetyl alcohol and/or stearyl alcohol, the two major components of cetearyl alcohol. Overall, 153 (74.3%) of 206 PCPs marketed as hypoallergenic contained BSCA baseline series allergens or ingredients that may cross-react with them. This highlights the need to increase public awareness and education about the potential dangers of purchasing ‘hypoallergenic’ PCPs.

Occupational Contact Dermatitis Caused by Artichokes.

Introduction: Few cases of skin diseases caused by exposure to artichokes have been published. Artichokes contain sesquiterpene lactones, which are known to be sensitizing. Irritant contact dermatitis (ICD) has also been diagnosed. To our knowledge, no protein contact dermatitis (PCD) has yet been reported to be induced by artichoke. Objectives: The aim of this study was to identify the different types of contact dermatitis that may be due to occupational exposure to artichokes and the professions concerned. Materials and Methods: We conducted a descriptive study, retrieving data from the French national database of occupational diseases for the period of 2001 to 2018. Results: Fifty-six cases were retrieved, and 10 cases were included in this study after data analysis and reading the clinical reports: 7 allergic contact dermatitis (ACD), 2 PCD, and 1 ICD caused by artichokes. Patients were farmers (4), agri-food workers (3), market gardener (1), cashier (1), and store employee (1). Conclusions: This is the first series of occupational contact dermatitis that can be induced by artichokes. Exposure to artichokes can lead to ICD, ACD, PCD, and perhaps contact urticaria. The sesquiterpene lactone mix patch test is not always sufficient to confirm an ACD by artichokes. Irritant contact dermatitis can be associated with ACD from artichokes or evolve on its own.

Seasonal Variation in Patch Test Results with European Baseline Series.

Aim To study the influence of season on patch tests results. Methods We conducted a retrospective epidemiological study which concerned all the patients of the Tunisian center, who consulted in the Dermato-Allergology Unit of Occupational Medicine Department of Farhat Hached University Hospital-Sousse (Tunisia) over a period of 07 years. All the patients were tested by the European Standard Battery allergens (BSE). Results The data of 1000 patch tests were analyzed during the study period. More than half of the patch tests (58.6%) was positive. In winter, 63% of patch tests showed a positive reaction versus 52% of patch tests in summer without a statistically significant association. However, results of lanolin alcohols, epoxy resin, and Sesquiterpene lactone mix varied significantly with season. Atopy was significantly associated with 18.8% of positive reactions in winter and only with 5.2% of positive reactions in summer (p = 0.015). Conclusion Seasonal variations in patch tests results were more significant with some allergens of European Standard Battery and in atopic patients.

Compositae sensitization in Danish children and adolescents.

Compositae plant sensitization in children is relatively frequent. From 1995-2006, we found a prevalence of 1.8% sesquiterpene lactone (SL) mix/parthenolide patch test positives among consecutive eczema patients <18 years. To report the results of patch test screening for Compositae sensitization in patients <18 years in the last 13 years. Children and adolescents <18 years, diagnosed with Compositae sensitization between 2007 and 2019, were included. Among 388 children tested, 12 (3%) were Compositae-sensitized, and 11 (2.8%) had positive reactions to SL mix. Compositae mix 5% pet. elicited positive reactions in six of seven patients tested, and dandelion extract 2.5% pet. in six of 10 patients tested. The mean age of the five girls and seven boys was 9.4 years and 11.7 years, respectively. Eleven children had a personal and one a family history of atopy, and 11 children had hand eczema. Only two were mono-sensitized to Compositae. SL mix is a suitable screening agent among children and adolescents in our area, well supplemented with Compositae mix 5% and dandelion extract. The study emphasizes the importance of Compositae screening in children with a personal and/or family history of atopy, hand eczema or widespread airborne dermatitis, summer exacerbation, and plant exposure.

Oral provocation of patients allergic to sesquiterpene lactones with German chamomile tea to demonstrate possible systemic allergic dermatitis.

Most patients with contact allergy to Asteraceae plants are patch test positive to sesquiterpene lactone mix (SLM). There are several reports among these patients of a flare-up of hand eczema after ingestion of food and beverages originating from Asteraceae plants. To investigate whether German chamomile tea can elicit systemic allergic dermatitis. Individuals with or without contact allergy to SLM were patch tested with an extract of German chamomile tea. Six weeks later, they were provoked with capsules containing either freeze-dried German chamomile tea or placebo capsules containing lactose, in a double-blind, randomized study. A numerical rating scale (NRS) was used to ascertain the volunteers' opinion of their hand eczema status. The study individuals were examined to detect a possible flare-up of healed patch test reactions to chamomile. None of the subjects had a flare-up of healed patch test reactions. According to the NRS, SLM-positive individuals experienced a significant worsening of hand eczema, independently of whether they received chamomile or lactose capsules. No evidence suggestive of systemic allergic dermatitis was found.

Chronic Actinic Dermatitis Revisited.

Chronic actinic dermatitis (CAD) is a persistent eczematous photodermatitis classically described in older, white men with contact allergy to plants. However, evidence from recent studies suggests that some demographics of CAD patients may be changing. The aims of the study were to determine the frequency of CAD in patients presenting with photosensitive eruptions and to identify the allergens and photoallergens most closely associated with this condition. We identified all patients with a diagnosis of CAD from 246 consecutive records of patients undergoing photopatch testing from July 1994 to June 2018 and summarized the demographics and test results in comparison with non-CAD patients. Nineteen (7.7%) of the 246 patients evaluated had CAD with a male-to-female ratio of 1:1.7 among CAD patients. Compared with non-CAD patients, photocontact allergy and/or contact allergy to sesquiterpene lactone mix and contact allergy to fragrances were significantly more common in CAD. Contact allergy to p-phenylenediamine was also common. The results of this study suggest that CAD presents in a broader demographic range, including both men and women of both light and dark skin types. Phototesting and photopatch testing should be considered when patients present with clinical findings consistent with CAD.

Screening for Compositae contact sensitization with sesquiterpene lactones and Compositae mix 2.5% pet.

Compositae contact sensitization may be difficult to diagnose, because of a lack of reliable screening allergens. To assess the suitability of Compositae mix II 2.5% pet. (CM2.5) as a screening mix in the baseline series combined with sesquiterpene lactone (SL) mix and parthenolide (PTH). CM2.5 was added to the baseline series, which included SL mix and PTH 0.1% pet., in January 2015, and PTH was included in TRUE Test Panel 3 in October 2015. All Compositae-sensitive patients diagnosed or tested in the next 4 years were assessed. Altogether, 57 patients (2.7%) presented with Compositae allergy. On primary testing in 53 newly diagnosed patients, SL mix elicited positive reactions most frequently (53% positive), followed by CM2.5 (47% positive), and PTH (45% positive). CM2.5 and PTH pet. elicited a few irritant reactions. Three patients had late reactions. Altogether, 16 patients (28%) were not detected by any of the three screening agents. SL mix is an indispensable, although insufficient, screening mixture in Denmark. It may be relatively safely supplemented with CM2.5 and PTH in the TRUE Test system for screening, but, when Compositae sensitization is suspected, further extracts should be tested on the basis of the history.

Unexpected positive patch test reactions to sesquiterpene lactones in patients sensitized to the glucose sensor FreeStyle Libre

Most diabetic patients sensitized to FreeStyle Libre react to isobornyl acrylate (IBOA), with a considerable number of them also showing unexpected positive patch test reactions to sesquiterpene lactone (SL) mix (SLM) tested in the baseline series. To compile patch test results of subjects affected, and provide potential explanations for this association. Fifty-three Freestyle Libre-allergic patients were patch tested with IBOA and/or SLM, and several were also patch tested with the components of SLM. Chromatographic analyses were performed on the glucose sensor, IBOA, and the components of SLM. Thirty-three patients reacted positively to the components of SLM, and 11 of 27 patients reacted positively to alantolactone, in particular. Gas chromatography-mass spectrometry (GC-MS) analyses did not detect these chemicals in the different parts of the glucose sensor, or in IBOA. Significant co-sensitizations between SLs on the one hand and the glucose sensor FreeStyle Libre and/or isobornyl acrylate on the other hand exist, without evidence of the presence of SLs via GC-MS analysis. Cross-reactions between them seem improbable. As a possible hypothesis, a common precursor for both, such as camphene, may exist.

Contact sensitization to plants of the Compositae family: Data of the Information Network of Departments of Dermatology (IVDK) from 2007 to 2016.

The Compositae plant family includes many thousands of species, making it one of the most widespread group of plants worldwide. Sensitization to Compositae allergens may occur in private or in occupational settings. To monitor the current spectrum of sensitization to Compositae allergens, especially in cooks and florists. We retrospectively analysed patch test results obtained with two Compositae mixes (CMs) (CM I and CM II; switch in October 2011), their individual components, and sesquiterpene lactone (SL) mix in 1492 cooks, 851 florists, and a control group (118 358 other patients) registered in the IVDK, 2007 to 2016. Florists reacted significantly more frequently to CM I and II (CM I, 8.7%; CM II, 10.6%) than did cooks (CM I, 2.1%; CM II, 0.8%) and controls (CM I, 1.3%; CM II, 1.2%). Additional testing with SL mix detected 14.3% more sensitizations than CM I or CM II alone. Florists are at considerable risk of sensitization to Compositae allergens. Patch testing with both CM and SL mix is recommended.

The Role and Diagnosis of Allergic Contact Dermatitis in Patients with Atopic Dermatitis.

Patients with atopic dermatitis (AD) have increased penetration of allergens, immune dysregulation (including shared cytokine pathways), and frequent use of emollients and topical medications, all of which may predispose toward developing allergic contact dermatitis (ACD). Recent systematic reviews have suggested that ACD is a significant clinical problem in both children and adults with AD. While this remains controversial, ACD remains an important comorbidity and potential exacerbant of AD in clinical practice. Common relevant allergens, include lanolin, neomycin, formaldehyde, sesquiterpene lactone mix, compositae mix, and fragrances that are commonly found in AD patients' personal care products. We herein review the clinical scenarios where patch testing is indicated in AD. In addition, we review the contraindications, preferred patch-testing series, pitfalls, and challenges determining the relevance of positive patch-test reactions in AD patients.

Eczema Crónico das Mãos Relacionado com Alergia de Contacto a Lactonas Sesquiterpénicas e Partenolido

As dermatites de contacto alérgicas por plantas podem manifestar-se sob padrões clínicos diversos. Descrevemos o caso clínico de doente do sexo feminino, de 63 anos com eczema das mãos. Perante a suspeita clínica de dermatite de contacto alérgica efectuaram-se provas epicutâneas com as séries básica (Grupo Português de Estudo das Dermites de Contacto - GPEDC) e de plantas, que revelaram positividades para a mistura de lactonas sesquiterpénicas 0,1% vas (++) e partenolido 0,1% vas. (++) em D2 e D4, o que permitiu o diagnóstico de alergia do contacto ao partenolido relacionada com a exposição ocupacional à planta margaça-de-inverno (Chamaemelum fuscatum) nas atividades de jardinagem. Salienta-se a importância de uma anamnese exaustiva para aumentar o nível de suspeição de dermatite de contacto alérgica e avaliar a relevância dos testes positivos a lactonas sesquiterpénicas e ao partenolido, como agentes etiológicos em casos de eczema crónico das mãos.

Prevalence of contact allergy in the general population in different European regions.

Population-based studies about contact allergy are scarce. To obtain reliable estimates of the prevalence of contact allergy in the general population in Europe. A cross-sectional study of a random sample from the general population, aged 18-74 years, in five different European countries (Sweden, the Netherlands, Germany, Italy and Portugal). In total, 12 377 subjects were interviewed and a random sample (n = 3119) patch tested to TRUE Test panels 1-3 and Fragrance Mix (FM) II, hydroxyisohexyl 3-cyclohexene carboxaldehyde (HICC) and sesquiterpene lactone mix. A positive patch test reaction is considered as contact allergy. In total, 27·0% [95% confidence interval (CI) 25·5-28·5] had at least one positive reaction to an allergen of the European baseline series, with a significantly higher prevalence in women than in men. The highest age-standardized prevalences (≥ 1%) were found for nickel (14·5%, 95% CI 13·2-15·8), thiomersal (5·0%, 95% CI 4·2-5·8), cobalt (2·2%, 95% CI 1·7-2·7), FM II (1·9%, 95% CI 1·5-2·5), FM I (1·8%, 95% CI 1·4-2·3), HICC (1·4%, 95% CI 1·0-1·9), p-tert-butylphenol formaldehyde resin (1·3%, 95% CI 0·9-1·7) and para-phenylenediamine (1·0%, 95% CI 0·6-1·3). Only nickel and thiomersal showed a statistically significantly different prevalence for contact allergy among the different European populations. Subjects reporting contact dermatitis in their lifetime (age-standardized prevalence 15·1%, 95% CI 13·8-16·3) had an increased risk for contact allergy (odds ratio 1·9, 95% CI 1·5-2·5). The risk of having a contact allergy was not increased in those with atopic dermatitis (prevalence 7·6%, 95% CI 6·7-8·6; odds ratio 1·0, 95% CI 0·7-1·4). Contact allergy to at least one allergen of the European baseline series was diagnosed in more than one-quarter of the general European population. Therefore measures to improve the primary prevention of contact allergy have to be enforced.

Lettuce contact allergy.

Lettuce (Lactuca sativa L.) and its varieties are important vegetable crops worldwide. They are also well-known, rarely reported, causes of contact allergy. As lettuce allergens and extracts are not commercially available, the allergy may be underdiagnosed. The aims of this article are to present new data on lettuce contact allergy and review the literature. Lettuce is weakly allergenic, and occupational cases are mainly reported. Using aimed patch testing in Compositae-allergic patients, two recent Danish studies showed prevalence rates of positive lettuce reactions of 11% and 22%. The majority of cases are non-occupational, and may partly be caused by cross-reactivity. The sesquiterpene lactone mix seems to be a poor screening agent for lettuce contact allergy, as the prevalence of positive reactions is significantly higher in non-occupationally sensitized patients. Because of the easy degradability of lettuce allergens, it is recommended to patch test with freshly cut lettuce stem and supplement this with Compositae mix. As contact urticaria and protein contact dermatitis may present as dermatitis, it is important to perform prick-to-prick tests, and possibly scratch patch tests as well. Any person who is occupationally exposed to lettuce for longer periods, especially atopics, amateur gardeners, and persons keeping lettuce-eating pets, is potentially at risk of developing lettuce contact allergy.

Epidemiological data on airborne contact dermatitis - results of the IVDK.

Airborne contact dermatitis (AirbCD) is not uncommon, according to a large number of published case reports and review articles. Epidemiological data on AirbCD based on larger clinical samples have not yet been published. To investigate demographic characteristics and patch test reactivity in patients diagnosed with both occupational and non-occupational AirbCD. A retrospective analysis of data from the Information Network of Departments of Dermatology (IVDK), 1994-2013, including 201 344 consecutively patch tested patients, was performed. One thousand two hundred and three patients (0.6%) were diagnosed with AirbCD, 421 (35.0%) of these with an occupational background. Occupational dermatitis and face involvement were more prevalent than in patients without AirbCD (n = 200 141). Sensitization to epoxy resin and sensitization to methylchloroisothiazolinone (MCI)/methylisothiazolinone (MI) were significantly associated with AirbCD, and there was a trend for sensitization to Compositae mix and/or sesquiterpene lactone mix to be associated with AirbCD. Adhesives, plastics, construction materials, paints and varnishes in occupational cases, and plants in non-occupational cases, were the most commonly documented culprit product categories. AirbCD is more common in patients with occupational dermatitis than in patients with non-occupational dermatitis. In our clinical sample, components of epoxy resin systems, MCI/MI and Compositae allergens were the most important contact allergens associated with AirbCD. Patch testing with additional allergens is important.

Sensitization patterns in Compositae‐allergic patients with current or past atopic dermatitis

An association between Compositae sensitization and atopic dermatitis has been suggested on the basis of case reports and clinical studies. To describe the characteristics of sensitization in Compositae-allergic patients with current and/or past atopic dermatitis. Consecutive Compositae-sensitive patients were selected for analysis if they had a history of (i) present and/or past atopic dermatitis or (ii) childhood flexural eczema or (iii) childhood eczema of any kind and a positive prick test result. Fifty-one persons (35 females and 16 males) were included. The mean age was lower and the percentage of males was slightly higher than in non-atopics. Testing with sesquiterpene lactone mix, parthenolide and Compositae mix 6% or 5% detected 96% of the patients. Occupational sensitization occurred in 22%. The sensitizing pattern did not differ much from that of non-atopics, except that dandelion was an important allergen in children. Cobalt allergy was the most frequent other contact allergy, occurring in 37%. Persons with current or past atopic dermatitis may become sensitized to Compositae at any age, both occupationally and non-occupationally. They should be screened for Compositae allergy on equal terms with non-atopics, except that dandelion extract should always be tested in children. Co-sensitization to cobalt was frequent, but probably not related to the plant allergy.

Sesquiterpene lactone mix as a diagnostic tool for Asteraceae allergic contact dermatitis: chemical explanation for its poor performance and Sesquiterpene lactone mix II as a proposed improvement

Two preparations are currently in use for the diagnosis of allergic contact dermatitis caused by Asteraceae: (i) Sesquiterpene lactone (SL) mix [three pure sesquiterpene lactones (STLs)], whose use has been questioned, owing to an insufficient rate of true-positive results; and (ii) Compositae mix, consisting of five Asteraceae extracts, which is problematic because of lack of standardization and questionable reproducibility. To analyse the reasons for the narrow sensitivity of SL mix from a chemoinformatic point of view, and to propose a solution by rational selection of alternative constituents for a new SL mix II covering a broader cohort of allergic patients. Structural and biological information on allergenic STLs was retrieved from databases and the literature, and molecular modelling and chemoinformatic computations were performed. An explanation for the insufficient hit rate of SL mix is that the three constituents possess extremely similar molecular structures/properties and do not represent well the structural diversity of allergenic STLs. STLs that are known as constituents of Compositae mix plants show much a wider diversity, which explains the higher positive rate. On the basis of their positions in chemical property space, a new collection of STLs that more evenly cover the overall structural diversity spectrum is proposed. SL mix II is likely to detect a larger number of patients sensitized to Asteraceae.