Incidence Of Allergic Contact Dermatitis Research Articles

Incidence of allergic contact dermatitis in Finland 1998-2021: A nationwide registry-based study.

Allergic contact dermatitis (ACD) may be chronic and can cause distress, disability, and absence from work. Nationwide epidemiological studies of ACD are sparse. To use national registry data to study the incidence and aetiology of ACD in the working age population of Finland. Patient records from the years 1998-2021 were obtained from the Finnish Care Register for Health Care. Study subjects aged 18-65 years were selected on the basis of a diagnosis of ACD. Total number of study subjects was 26 701. The incidence of ACD increased until 2016 after which it started to decrease. The increase was more marked in females and ACD was particularly common in women reporting reactions to cosmetics and other chemical products and in people of both sexes reacting to adhesives. The incidence 'ACD of unspecific cause' has decreased since 2016. The most commonly reported allergens were metals, followed by cosmetics. One fourth of subjects had ≥2 ACD diagnoses. The incidence of ACD in working age subjects rose from 1998 to 2016, especially in females. However, the incidence has been decreasing since 2016. Our findings highlight the ongoing and even increasing burden of ACD among the working age population.

Allergic Contact Dermatitis to Octyl Cyanoacrylate Skin Glue After Surgical Wound Closure: A Systematic Review.

The rising incidence of allergic contact dermatitis (ACD) after cyanoacrylate adhesive use necessitates a comprehensive understanding of its clinical presentations, risk factors, and management. In this systematic review, we conducted an exhaustive search following PRISMA guidelines within Medline and PubMed databases to identify studies reporting cases of ACD resulting from cyanoacrylate adhesive application in wound closure. A total of 47 studies, covering 193 ACD cases, were included in our analysis. These cases involved 35 male, 120 female patients, and 38 cases without gender information (M:F ratio = 1:3.43), with ages ranging from 7 to 92 years (mean age 43.9 years). The majority of cases (n = 140) were part of 6 orthopedic studies, focusing on joint replacements (n = 68), orthopedic surgeries (n = 38), and breast surgeries (n = 29). The remaining 58 cases encompassed various surgical procedures. Common clinical manifestations included swelling, pruritic rash, erythema, vesicles, and itching around the surgical sites, typically appearing around 10 days post-adhesive application (within a range of 6 hours to 6 weeks). Patients with prior exposure to 2-octyl cyanoacrylate tended to exhibit earlier symptoms. Similar rates of dermatitis were observed across different adhesive brands, suggesting brand independence. Treatment strategies involved adhesive removal, administration of steroids and antihistamines, meticulous wound care, and, in some cases, surgical intervention. Notably, 3.1% of the 193 cases required surgical intervention. Risk factors, including a history of atopic dermatitis, high body mass index, diabetes, prior adhesive exposure, and surgical history, were identified in the studies. Patch tests confirmed 2-octyl cyanoacrylate as the allergen in 21 studies. Our review aims to enhance health care professionals' understanding of ACD resulting from the use of cyanoacrylate adhesive, facilitating improved postsurgical management and prevention strategies. Recognizing diverse risk factors, understanding varying clinical presentations, distinguishing ACD from infection, and employing appropriate treatment approaches are essential for achieving optimal outcomes in such cases.

CD05 Return of cement-related allergic contact dermatitis: a case series and review of the literature

Abstract We report a case of a 23-year-old male bricklayer of 6 years who presented to our cutaneous allergy service with a 3-year history of a hand and foot dermatitis. Workwear included leather work boots and fibreglass gloves, which he used intermittently. His past medical history included childhood eczema and hay fever. Patch testing revealed strong reactions (++) to potassium dichromate and cobalt. Both were felt to be of current relevance due to cement exposure at work and from the leather in his boots. A review of our database revealed 8088 patients tested to the British Society for Cutaneous Allergy standard battery. A total of 662 were positive to cobalt and 339 to potassium dichromate. Of these, 121 patients were positive to both potassium dichromate and cobalt. Four of these were bricklayers, only one of whom was seen prior to the European Union (EU) cement directive. All reported hand dermatitis, and two also had foot involvement. In order to minimize chromate allergy, EU legislation in 2005 banned the sale of cements containing more than 2 parts per million (0.0002%) of hexavalent chromium. This minimal level is often achieved by adding a reducing agent such as ferrous sulphate to chromium III, which is less bioavailable and less likely to penetrate through the skin. Work suggests that rates of chromium-related allergic contact dermatitis (ACD) have diminished following this legislation with the incidence rate ratio between 2002–2004 and 2005–2009 falling to 0.37 (P = 0.001) in cement workers (Stocks SJ, McNamee R, Turner S et al. Has European Union legislation to reduce exposure to chromate in cement been effective in reducing the incidence of allergic contact dermatitis attributed to chromate in the UK? Occup Environ Med 2012; 69:150–2). Despite this change, sensitization is still possible without adequate protection, such as in our patient’s case. Additionally, the reducing agent’s activity diminishes over time; therefore, if it is not appropriately stored or used after its recommended shelf life, it may expose users to higher levels than are regulated. Despite the low concentration of cobalt in cement (0.01%), allergy may occur. It has been noted that sensitization to both metals is common in bricklayers, but this coexisting sensitivity was not seen in other professions where patients were allergic to chromium (Giménez Camarasa JM. Cobalt contact dermatitis. Acta Derm Venereol 1967; 47:287–92). We aim to highlight the ongoing issue of ACD associated with cement and review the recent history around potassium dichromate and cobalt in this regard.

Potential for Allergic Contact Dermatitis in Popular Hair Care Practices and Ingredients.

The incidence of allergic contact dermatitis (ACD) due to personal care products is rising in parallel with increasing product availability and consumer interest. Hair products specifically represent a significant source of potential allergens, including preservatives, surfactants, emulsifiers, fragrances, adhesives, and dyes. ACD due to hair care products can present as dermatitis in the distinctive "rinse-off" distribution, involving the neck, eyelids, and lateral face in addition to the scalp. Herein, the authors review ingredients in hair care products that can cause ACD and practical tips for allergen identification.

Allergic contact dermatitis from vitamins: A systematic review.

Background and AimsVitamins are bioactive compounds naturally found in many different types of food and required by the human body for many biological functions and enzymatic activities. Due to their antioxidant properties, certain vitamin derivatives have been synthesized for inclusion in many cosmetics, thus leading to an increasing incidence of allergic contact dermatitis (ACD) cases. Therefore, the present review may be helpful to provide an insight into the sensitizing role of at least certain vitamins and may also offer possible patch test alternatives for definitive diagnosis.MethodsThis study was conducted in accordance with the Preferred Reporting Items for Systematic reviews and Meta‐Analyses (PRISMA) guidelines. Literature search regarding ACD cases to vitamins was performed using the Medline, PubMed, Scopus, EMBASE, and Google Scholar databases from January 1940 up to June 2021.ResultsA total of 4494 articles matched the keywords used for the researched. Records removed before screening included 15 duplicate articles and 3429 not eligible articles (e.g., not written in English, studies on animals, not relevant to the topic). A total of 1050 articles underwent the screening phase and 258 were therefore excluded as they were not primary studies. Subsequentially, 792 articles were considered eligible for the review and 688 of them were finally excluded as they did not report the outcome of interest. Therefore, 104 articles were definitely included in the present review.ConclusionACD to vitamins is still probably an underestimated issue in cosmetology, as many vitamins are considered “natural” and therefore “safe” ingredients. On the contrary, according to current literature, almost all vitamins contained in topical products are able to induce allergic reactions, with the exception of vitamin B2 and vitamin B9. Patch tests are not standardized, thus leading to difficulties in diagnosis.

Contact Sensitization to Allergens of Biological Origin from the Compositae Family and Original Extracts of Ubiquitous Weed Plants of Vojvodina among Patients with Chronic Venous Insufficiency.

The use of alternative treatment methods, particularly medicinal herbs from the family Compositae, significantly contributes to the increase in the incidence of allergic contact dermatitis among patients with chronic venous insufficiency. Estimating frequency of contact sensitization among patients with chronic venous insufficiency and determining the most common contact sensitizers from the series of bio-origin allergens from the Compositae family and ubiquitous weeds of Vojvodina. The total number of 266 patients with suspected contact dermatitis was divided into two groups: the experimental group consisted of patients with chronic venous insufficiency (EG), and the control group consisted of patients without chronic venous insufficiency (CG). All subjects were tested with allergens of biological origin from the family Compositae, screening allergen SL-mix and original extracts of ubiquitous weed plants of Vojvodina. Patch test revealed a positive reaction to allergens of the Compositae family in 6.69% in the experimental group, and in 4.17% in the control group. The standardized response rate to the SL-mix in the experimental group was 2.07%, while in the control group, it was 1.51%. The presence of a positive reaction to at least one extract of ubiquitous weed plants of Vojvodina was determined in 6.11% in the experimental group, and in 3.23% of patients in the control group. No statistically significant difference in response rates was found between the examined groups. Establishing the diagnosis of Compositae dermatitis can be supplemented by additional testing with weed plant extracts from a specific geographical area, resulting in the detection of novel unknown allergens.

Incidence and risk factor of allergic contact dermatitis to 2-octyl cyanoacrylate and n-butyl cyanoacrylate topical skin adhesives

Although the use of topical skin adhesives has increased as an alternative to conventional skin closure methods, studies on the incidence and risk factors of allergic contact dermatitis (ACD) to topical skin adhesives have been limited. The purpose of this study was to investigate the incidence and risk factors of ACD after the use of 2-octyl cyanoacrylate and n-butyl cyanoacrylate topical skin adhesives. We retrospectively reviewed 1145 patients (739 patients with 2-octyl cyanoacrylate and 406 patients with n-butyl cyanoacrylate) who underwent skin closure with topical skin adhesives. Variables suspected to correlate with ACD were retrieved from medical records and analyzed to determine risk factors. The incidence of ACD from the use of 2-octyl cyanoacrylate and n-butyl cyanoacrylate topical skin adhesives was 2.7% and 2.2%, respectively. There was no statistically significant difference in the incidence between the two ingredients. In logistic regression analysis, none of the variables were found to increase the risk of ACD in both 2-octyl cyanoacrylate and n-butyl cyanoacrylate topical skin adhesives. As ACD occurs without risk factors in 2–3% of patients who used 2-octyl cyanoacrylate or n-butyl cyanoacrylate topical skin adhesives, clinicians and patients should be aware of these facts before using topical skin adhesives.

Allergic Contact Dermatitis Among Healthcare Workers Exposed to Glutaraldehyde

Background: One of the health problems that can be caused by glutaralaldehyde is allergic contact dermatitis (ACD). However, the causal relationship between glutaraldehyde and DKA is still unclear, so it is necessary to look for some evidence regarding this relationship. The search for evidence is also equipped with a seven-step assessment of occupational diseases therefore it can assist occupational medicine doctors who find patients with ACD and have a history of exposure to glutaraldehyde. Methods: Literature search using Pubmed, Scopus and JSTOR databases. The keywords used are ‘healthcare worker OR healthcare personnel’, ‘glutaraldehyde’ and ‘allergic contact dermatitis. Article selection was performed using the defined inclusion and exclusion criteria. Selected articles will be critically reviewed based on etiological studies from the Oxford Center of Evidence-Based Medicine. Result: It was in six selected articles that met the inclusion and exclusion criteria. The main finding after a critical review was that glutaraldehyde may increase the risk of ACD. Conclusion: There is a relationship between 1% glutaraldehyde exposure and the incidence of ACD in health workers. To establish the diagnosis of occupational diseases in health workers who are exposed to glutaraldehyde, seven steps of diagnosis of occupational diseases are used.

Contact Dermatitis in Children: Indications for Pediatric Patch Testing

Allergic contact dermatitis (ACD) is often underdiagnosed in pediatric patients, especially those with a diagnosis of atopic dermatitis (AD). Recent literature has shown that the incidence of ACD in children is increasing and several factors of atopy play a role. It is important to recognize the possibility of ACD in the pediatric population and perform extended patch testing with the North American Contact Dermatitis Group (NACDG) core series in these patients. Patch testing can help with allergen identification and management of chronic dermatitis.

Alergia kontaktowa - przyczyna depresji i bezsenności?

Nowoczesny styl życia, zanieczyszczenia środowiska i postępująca industrializacja przyczyniają się do wzrostu zachorowań na alergiczne kontaktowe zapalenie skóry, które jest reakcją odpornościową na niskocząsteczkowe substancje ? hapteny. Klinicznie manifestuje się na skórze obrzękiem, pęcherzami i pęknięciami, którym dodatkowo towarzyszy ból i świąd. Zapalny charakter choroby oraz widoczne na skórze zmiany, przyczyniają się do pogorszenia jakości życia chorych oraz zwiększają prawdopodobieństwo wystąpienia zaburzeń depresyjnych. Niewątpliwie objawy z kręgu zaburzeń lękowych i depresyjnych (przebiegających z bezsennością) mogą dotyczyć nawet 60% pacjentów dermatologicznych. Ponadto, jakość snu oraz stan skóry są ze sobą ściśle skorelowane i wzajemnie na siebie oddziałują. Niezwykle obiecujące są wyniki badań ostatnich lat, które wskazują, że leki przeciwdepresyjne, w praktyce klinicznej stosowane w leczeniu bezsenności, hamują również reakcję nadwrażliwości kontaktowej. Dlatego niniejsza praca jest poświęcona problemowi współwystępowania chorób skóry, depresji i bezsenności, roli układu odpornościowego w etiologii tych chorób oraz immunomodulacyjnych właściwości leków przeciwdepresyjnych, mogących wywierać terapeutyczne efekty w chorobach z zakresu psychodermatologii.

The Role of Topical Antibiotic Prophylaxis in Oculofacial Plastic Surgery: A Randomized Controlled Study

The usefulness of topical antibiotic prophylaxis for routine oculofacial plastic surgery is not well established. Given concerns such as contact dermatitis, antibiotic resistance, and healthcare costs in conjunction with a low baseline rate of surgical site infections, the investigators sought to determine the frequency of infection with and without the use of topical antibiotic prophylaxis. Randomized, controlled, unmasked clinical trial. Adult patients undergoing routine periocular surgery without prior history of periocular surgical site infection, need for perioperative oral or parenteral antibiotics, or allergy to all study medications. Participants were randomized before surgery to receive either antibiotic or placebo (mineral oil and petrolatum-based) ointment after surgery. Outcomes were measured at the first postoperative visit. The 2-tailed Fisher exact test was used to compare outcomes between groups. The primary outcome was the incidence of surgical site infections. The secondary outcomes included stratification of infections by patient risk characteristics, incidence of allergic contact dermatitis, and incidence of wound complications. Four hundred one participants were enrolled and randomized, and 13 participants did not proceed with surgery or were lost to follow-up. High-risk features for infection were identified in 24% of the placebo group and 21% of the antibiotic group. Surgical site infections were more common in the placebo group (2.7% vs. 0.0%; P= 0.025). The rate of contact dermatitis was similar (0.5% vs. 0.5%; P= 1.00), as was the rate of wound dehiscence (2.7% vs. 3.5%; P= 0.77). Among the placebo group, the incidence of infections in the low- and high-risk participants was 2.9% and 2.2%, respectively. Infections were treated with oral or topical antibiotics and resolved without complication, except in 1 patient who required 2 subsequent surgeries to address the sequelae. After routine oculofacial plastic surgery, patients treated with a topical antibiotic ointment showed a lower risk of surgical site infection compared with patients treated with a nonantibiotic ointment.

Skin diseases affecting a population occupationally exposed to terrestrial fauna and flora in Brittany over a 15-year period.

Brittany is the leading agricultural production region of France where many workers are exposed to the local flora and fauna. The aim of the study is to describe the different skin diseases found among the workers occupationally exposed to the terrestrial fauna and flora in Brittany, and to assess the possible over-representation of some work environments. This was a retrospective, descriptive study carried out between 1 October 2002 - 30 April 2017, based on the coding of files from a multi-disciplinary occupational dermatology clinic at the Brest University Hospital. The study population of 84 patients was drawn from a total 788 patients seen during this period. Allergic contact dermatitis was the most frequently coded diagnosis with 35 cases (42%). There were 13 cases of irritant contact dermatitis (15%). Infectious diseases were poorly represented with only 5 cases (6%).The 6 most frequently represented occupations were packers in the agri-food industry (12.0%), cattle farmers and tomato greenhouse workers (both 10.7%), maintenance workers of parks and gardens (9.5%), agri-food factory cleaning operatives (8.3%) and pig farmers (7.1%). There was a marked incidence of allergic contact dermatitis and irritative contact dermatitis, mostly occupational in origin. While no specific diseases were found among these workers, some of the allergens and irritants identified may be specific to certain work environments. Overall, there did not seem to be a major risk of occupational dermatoses among workers exposed to Brittany's terrestrial fauna and flora in this population, compared with other professional sectors, such as hairdressing or care work. The incidence rate of the cases of occupational skin diseases in this population is assessed from 3 - 5 cases per 100,000 workers.

The Rising Incidence of Allergic Contact Dermatitis to Acrylates.

Allergic contact dermatitis (ACD) caused by (meth)acrylates used in nail products is being increasingly reported in nail technicians and consumers. The aim of the study was to assess the incidence of sensitization to (meth)acrylates in technicians and users of nail products with ACD, referred for patch testing in a tertiary center, during the last 10 years. All patients with ACD, who reported a profession associated with cosmetic nail procedures or use of such services and were referred for patch tests in our department between January 2009 and December 2018, were identified. The incidence of positive sensitization to (meth)acrylates was assessed. Contact allergy to 1 or more (meth)acrylates was found in 116 (74.4%) of 156 nail technicians or nail product users, all women. One hundred thirty-eight (88.5%) were occupationally exposed, and 18 (11.5%) were consumers. In addition, there was a statistically significant increase in (meth)acrylate ACD during 2014-2018 (100/127 cases [79%]) when compared with 2009-2013 (16/29 cases [55%]). The most common sensitizer among the 156 allergic individuals was ethylene glycol dimethacrylate, which was positive in 113 cases (72.4%), and among patients with acrylate-positive patch test, the rate was 97.4%. Our experience confirms the worldwide changing landscape of rising (meth)acrylate sensitization in nail technicians and nail products users with ACD. Efforts to improve prevention are needed, and clinicians should have a high index for suspicion in this occupational group.

M507 ALLERGIC CONTACT DERMATITIS ON THE EAR: NOT COMMONLY HEARD OF

There is an increasing incidence of allergic contact dermatitis to corticosteroids. However, this diagnosis is being undetected or misdiagnosed, since topical corticosteroids are the first line treatment for inflammatory skin disorders.

Patch Testing in Allergic Contact Dermatitis over the Lower Extremities.

Background:There is an increased incidence of allergic contact dermatitis (ACD) over the lower extremities due to over-the-counter topical preparations, occupational risk, and usage of several chemicals in the manufacture of designer footwear.Aims and Objectives:The aim of the study was to identify the common allergens and polysensitization pattern involved in ACD over the lower extremities.Materials and Methods:It is a cross-sectional study, wherein a total of 80 patients were recruited over a period of 18 months. Demographic and clinical characteristics were noted. Patch test was done with the Indian standard series. Interpretation of patch test readings was read according to the International Contact Dermatitis Research Group criteria at 48 and 96 h.Results:There were 45 males and 35 females (M:F= 1.3:1). Mean age was 41.65 years. Most of the patients belonged to 21–40 years age group. Farmers, homemakers, and students were commonly affected. Most common presentation was itching, hyperpigmentation, and scaly plaques over the feet. Patch test was performed in 75% of the patients. One or more positive results were observed in 57% of the patients. Common allergens noted were potassium dichromate (35%), followed by nickel sulfate (23.5%), mercapto mix, and mercaptobenzothiazole. Potassium dichromate and nickel were the common allergens reported in males and females, respectively. Neomycin was the common medication responsible for dermatitis medicamentosa. Polysensitization was seen with mercapto mix, mercaptobenzothiazole, potassium dichromate, and fragrance mix.Conclusion:Potassium dichromate and nickel were the common allergens responsible for ACD over the lower extremities. Polysensitization was seen commonly with mercapto mix, mercaptobenzothiazole, and fragrance mix.Recommendation:Screening for usage of topical preparations and late patch test readings (96 h or more) is recommended.

Common allergens present in personal care products: identification, diagnosis, and management.

The incidence of allergic contact dermatitis (ACD) reactions to personal care products has progressively increased, affecting women more so than men. Fragrances and preservatives are the major sensitizers behind cosmetic-induced ACD, due to their ubiquitous presence in these products, though emulsifiers, ultraviolet filters, and botanical allergens have been implicated as well. While patch testing is the standard for diagnosing ACD, many cosmetic-specific antigens are not currently included within the commercially available kits. Therefore, patch testing for potential cosmetic-induced ACD should be supplemented with additional compounds commonly found in personal use products. Effective treatment of ACD must involve accurate identification and removal of the offending agent.

Allergic Contact Dermatitis Due to Paraphenylenediamine: An Update

Paraphenylenediamine (PPD) is an amine that is mainly used as an ingredient in hair dyes and henna tattoos. The incidence of allergic contact dermatitis to PPD is increasing, particularly in younger patients. In this article, we review the main sources of PPD and the substances with which it can interact and present a practical algorithm for diagnosing and treating suspected cases of PPD allergy.

Actualización en la dermatitis de contacto alérgica por parafenilendiamina

Paraphenylenediamine (PPD) is an amine that is mainly used as an ingredient in hair dyes and henna tattoos. The incidence of allergic contact dermatitis to PPD is increasing, particularly in younger patients. In this article, we review the main sources of PPD and the substances with which it can interact and present a practical algorithm for diagnosing and treating suspected cases of PPD allergy.

A study on correlation between allergen and allergic contact dermatitis

<p class="abstract"><strong>Background:</strong> <span lang="EN-IN">Agents which cause contact dermatitis are simple chemical compounds and by themselves these agents will not cause sensitization and are called haptens. These require another molecule usually a protein called the carrier molecule derived from the epidermis to cause allergic sensitization. The confirmation of contact dermatitis is done by the patch testing. There is no substitute for the patch test in the management of allergic contact dermatitis.</span></p><p class="abstract"><strong>Methods:</strong> <span lang="EN-IN">After selecting the patient suspected to have allergic contact dermatitis the findings were recorded in the proforma which also includes the systemic examination of CVS, CNS, GIT and respiratory system to study systemic correlation if any. Investigation were done which included Hb%, TLC, DLC, urine routine and microscopic examination, patch testing and other special investigations if required. The patient was subjected to patch testing after the acute stage has subsided and the patient was on no therapy with topical or systemic steroids prior to patch testing</span>.<strong></strong></p><p class="abstract"><strong>Results:</strong> <span lang="EN-IN">The incidence of allergic contact dermatitis due to cosmetics was found in 7 (5.6%) cases. In that hair dye (PPD) inducing dermatitis was found in 4 (57.4%) and due to hair oil 1 (14.2%), kumkum 1 (14.2%) and Sunsilk shampoo 1 (14.2%). The incidence of PPD sensitivity in this series of 125 cases was 4 (3.2%). </span></p><p class="abstract"><strong>Conclusions:</strong> <span lang="EN-IN">PPD is a well-known potent sensitizer, it is a chief constituent of the commonly used hair dyes and also some other cosmetics like nail polish.</span></p>

Pediatric Allergic Contact Dermatitis: Clinical and Epidemiological Study in a Tertiary Hospital

BackgroundFew epidemiological studies have investigated the incidence of allergic contact dermatitis in children. Underdiagnosis has been observed in some studies, with many cases in which the condition is not suspected clinically and patch tests are not performed. However, the prevalence of pediatric sensitization to allergens has been reported to be as high as 20%, and the diagnosis should therefore be contemplated as a possibility in this age group. Material and methodsWe performed a retrospective analysis of the skin allergy database of the Dermatology Department of Consorcio Hospital General Universitario de Valencia. Children between 0 and 16 years of age diagnosed with allergic contact dermatitis in the previous 15 years (between 2000 and 2015) were included in the analysis. Epidemiological (age, sex, history of atopy) and clinical (site of the lesions, allergen series applied, positive reactions, and their relevance) variables were gathered. ResultsPatch tests had been performed on 4,593 patients during the study period. Of these, 265 (6%) were children aged between 0 and 16 years. A positive reaction to at least one of the allergens tested was observed in 144 (54.3%) patients in that group. The allergens most frequently identified were the following (in decreasing order of frequency): thiomersal, cobalt chloride, colophony, paraphenylenediamine, potassium dichromate, mercury, and nickel. The sensitization was considered relevant in 177 (61.3%) cases. ConclusionsMore than half of the children studied showed sensitization to 1 or more allergens, with a high percentage of relevant sensitizations. All children with a clinical suspicion of allergic contact dermatitis should be referred for patch testing. As no standardized test series have been developed for this age group, a high level of clinical suspicion and knowledge of the allergens most commonly involved are required when selecting the allergens to be tested.