Latex allergy in children.

Allergic or immediate hypersensitivity reactions to natural rubber latex have been reported in children with increasing frequency in the last few years, although severe anaphylactic reactions are rare. Indubitably rubber has been employed in thousands and thousands of everyday products for over a century, yet only recently has natural rubber latex allergy been recognized as a substantial medical problem. Children with spina bifida undergoing multiple surgical procedures, as well healthy babies appear at high risk for natural rubber latex allergy, with life-threatening reactions reported during surgery or while playing with balloons. Skin prick testing is the preferred diagnostic method, especially in the prick by prick version. Parents of children with latex allergy should take caution that their babies avoid contact with rubber products, and that a latex-free environment is set during procedures. Since even minimal contact with natural rubber latex products may produce reactions, the primary treatment for latex allergy is avoidance. In this paper we review the new natural rubber latex allergens, as well as the cross-reactions regarding the latex-fruit syndrome since the recent characterization of a number of profilins has also greatly widened the number of possible reactions.     

Prevalence of type I allergy to natural rubber latex and type IV allergy to latex and rubber additives in operating room staff with glove-related symptoms.

There is lack of data on the prevalence of latex allergy in the health care setting in Iran. This study was performed to determine the prevalence of type I latex allergy and type IV allergy to latex and rubber additives among the operating room staff with glove-related symptoms in 13 general hospitals in Tehran. Skin-prick tests with commercial latex extract, patch tests with latex and 25 rubber additive series, and total and latex-specific IgE detection were performed on the operating room staff who reported latex glove-related symptoms. Five hundred twelve self-administered questionnaires (100%) were completed by all operating room staff and latex glove-related symptoms were reported by 59 (11.5%) employees. Among all symptomatic operating room staff tested, the prevalence of type I latex allergy was 30.5% and the prevalence rates of type IV allergy to latex and rubber additives were 16.7 and 14.6%, respectively. The most positive patch test result with rubber additives was related to tetramethylthiuram monosulfide (38.5%). The risk factors for type I latex allergy were female sex (p = 0.009) and positive patch test with rubber additives (p = 0.012). Subjects who had positive patch test with latex were significantly more likely to have positive patch test with rubber additives (p < 0.0001). Our results showed a high prevalence of type I latex allergy and type IV allergy to latex and rubber additives. Based on this study, we recommend eliminating powdered latex gloves from the operating rooms of the 13 studied general hospitals and support the substitution of powder-free latex gloves.     

Latex Allergy: A Patient and Health Care System Emergency

Latex allergy, an IgE-mediated reaction to proteins retained in finished natural rubber latex products, has become one of the most pervasive problems in medicine. Latex allergy has resulted in death, progressive asthma, severe food allergy from cross-reactivity, and disability of health care professionals with the accompanied loss of self-esteem and income from their inability to work in their chosen profession. This article reviews the risks of latex allergy and proposes strategies for prevention and management of the problem. [Kelly KJ, Walsh-Kelly CM: Latex allergy: A patient and health care system emergency. Ann Emerg Med 1998;32:723-729.]     

Summary of appropriate measures to prevent natural rubber latex allergy

This paper presents a short overview of the diagnostics and background of type I allergy to natural rubber latex proteins and makes recommendations for preventing corresponding allergic diseases in the future. These recommendations and prevention strategies are based on the current knowledge of latex allergy presented in the literature and are addressed to legislative bodies; manufacturers; directors of hospitals; those working at nursing facilities and physicians' and dentists' practices; as well as to other health service employees. Primary prevention is the focus but advice is also given on secondary prevention. The major preventive aim is the elimination of causative protein allergens in all latex devices and thus, the minimization of latex-related health problems.     

Latex allergy among operating room personnel in Turkey.

This study was performed to evaluate the prevalence of latex allergy among health care workers in Turkey, as well as to compare the medical histories with the skin test results and investigate the risk factors. Using a 1/100 weight/volume commercial skin prick test (SPT), we investigated latex sensitization in 206 health care workers who regularly use latex products. One hundred atopic and 100 nonatopic patients without occupational latex exposure were also examined as control groups. Latex SPTs were positive in 10 health care workers (9.22%), whereas none of the control patients was found to have positive SPT to latex. Health care workers were divided into two groups based on the latex SPT results. There was no significant difference between the latex SPT-positive and -negative health care worker groups according to age, sex and total exposure time to latex. In the latex SPT positive group, daily exposure time and daily glove use were significantly higher (p <0.05). The symptoms related to latex products were limited to hands and itching was present in all, however, erythema was found in 68.4%, and contact urticaria in 52.6% in the latex SPT positive group. These symptoms in the latex SPT negative health care group were 21.4%, 14.4%, and 1.6%, respectively (p <0.0001). History of allergic rhinitis, bronchial asthma and conjunctivitis were also higher in the SPT-positive group (p <0.05). Additionally, we found sensitivity to house dust mites and/or grass pollens in seven cases of latex allergy. Patch tests with rubber additives were positive in five out of 42 medical care workers. Two surgeons were found to have both type-I hypersensitivity to latex and type-IV hypersensitivity to rubber additives. Our results suggest that the frequency of latex allergy is higher in the atopic health care workers with a high exposure to latex, and that SPT is a sensitive, safe, cheap and easy method of testing the diagnosis of latex hypersensitivity.     

Identification of latex UDP glucose pyrophosphorylase (Hev b UDPGP) as a novel cause of latex fruit allergy syndrome

Based on a recently published unusual ase of food allergy in a latex-allergic patients, the present study identifies Hev b UDPGP as a novel allergen in natural rubber latex able to cause latex-fruit allergy syndrome and as a novel, potential pan-allergen in vegetable foods.     

Latex allergy in children: a follow-up study

BackgroundNatural rubber latex allergy is an important health problem. Multiple contacts with latex in childhood are a risk factor. Many aspects of this disease are still unknown, one of which is the clinical outcome of these children. The aim of this study was to evaluate the clinical and epidemiological features of latex allergy and compliance with latex avoidance instructions in allergic children.Material and methodsSeventeen consecutive patients with a history of latex allergy, fruit allergy or chronic urticaria were selected. The patients underwent a skin prick test and determination of specific-IgE to latex at the start and at end of the study (median follow-up: 3 years). At diagnosis, patients with a positive result to one of the tests and a clinical history of latex allergy were considered allergic; patients with a positive test but without a clinical history suggestive of allergy were considered sensitized. These children were given latex avoidance instructions.ResultsEleven children (64.7 %) were classified as allergic and 6 (35.3 %) as sensitized. Five patients had undergone latex-free surgery after diagnosis without incident. During follow-up, 11 patients (8 allergic and 3 sensitized) had contact with latex. Contact occurred in the home in 10 children, and all were symptomatic. Specific-IgE levels to latex at the end of the study were significantly higher in patients who had contact with latex during the follow-up period than in those without latex contact.ConclusionsStrict compliance with latex avoidance instructions is essential both inside and outside the hospital. Greater emphasis should be placed on reducing latex exposure in the home and school environments, as such contact could maintain positive IgE-antibody levels.     

Latex allergy

Latex allergy has become an increasing cause of morbility in the last few years and is now recognized as an international health problem. The prevalence of latex sensitization among the general population is less than 1 %. The groups at highest risk include healthcare workers, rubber industry workers, patients with a history of multiple surgical procedures, particularly children with spina bifida and urogenital abnormalities, atopic individuals, and patients with certain fruit allergies (especially kiwi, avocado, chestnut and banana). The molecular and immunological characteristics of several natural latex allergens have been identified. Symptoms range from contact urticaria to anaphylaxis. Diagnosis is based on clinical history and is confirmed by skin prick tests. Measurement of serum specific IgE to latex can also be useful. The best treatment is latex avoidance and substitution by other materials. However, because latex products are ubiquitous in medical and nonmedical devices of daily use, a latex-free environment is not easy to achieve. In some patients, immunotherapy could be an alternative.     

A new quantitative in vitro for the detection of latex-specific IgE antibodies

Immediate-type hypersensitivity to latex allergens has resulted in anaphylactic shock and death in numerous reported cases. The allergenic proteins of latex are contained within the natural rubber extract of Hevea brasiliensis and are eluted into the final product during the manufacturing process. The quantity and types of latex allergens found in different latex products depends on the manufacturing process. Not all of these allergens are available for use in the latex prick skin test, and as a result, such tests may not be conclusive. Furthermore, application of such allergens to the skin of undiagnosed hypersensitive individuals may have harmful effects on their health. Therefore, it is important to be able to utilize in vitro methods, which reliably identify latex allergy without placing hypersensitive individuals at risk. We have developed a relatively simple and new enzyme immuno-assay (EIA) method for the detection of latex allergy. This in vitro method is quantitative and allows for the classification of allergy to latex in a short time. In comparative studies, ninety-nine serum specimens with documented clinical history of latex allergy were tested by this method, and the results paralleled those of the skin prick test performed by an independent group. The data showed that the specificity and sensitivity of our assay approaches 97.5% and 100%, respectively. We conclude that, by using a simple assay, the detection of specific IgE to latex proteins may be valuable for screening individuals and for the diagnosis of allergy to latex.     

Latex allergy and fruit cross-reaction in subjects who are nonatopic.

Since the first case reported in 1927, latex allergy has attracted the attention of allergists including its capacity to cross-react with fruits. To evaluate the frequency of sensitivity to some fruit allergens shown to cross-react with latex, we evaluated 82 patients (43 men and 39 women, aged between 18 and 45 years) with latex allergy. All patients underwent skin tests with various fruit extracts that potentially cross-react with latex. Only patients with negative prick tests successively underwent prick-by-prick tests with fresh fruits. Thirty-nine of 82 patients (47.5%) were found to have positive skin tests. Prick tests with fruit extracts were positive in 28 patients (kiwi, 21 patients; banana, 17 patients; avocado, 8 patients; and papaya, 3 patients), and the prick-by-prick test had positive results in 11 patients (kiwi, 7 patients; banana, 4 patients; and avocado, 3 patients). In our experience patients with latex allergy are at a high risk of sensitization to some fruits and they often develop allergic reactions, even severe ones, after eating them; for this reason fruit sensitization should be taken into consideration when investigating patients allergic to natural rubber latex.     

Diagnosis of latex hypersensitivity: comparison of different methods

A standardized diagnostic protocol for latex allergy is still lacking, although latex-related manifestations are a common health problem especially among health-care workers and patients with spina bifida. The present study was aimed to compare different in vivo (skin prick test, patch test, use test) and in vitro (specific IgE determination by CAP-Rast, basophil histamine release assay, immunoblot) methods to diagnose latex sensitization in 47 health care workers reporting latex-related manifestations. According to the established criteria, 20 subjects (42.5%) were considered as truly sensitized to latex, 18 with type I and 2 with type IV hypersensitivity. Skin prick test displayed the highest diagnostic efficiency, having higher sensitivity and specificity than specific IgE determination and use test. Patch test with rubber chemicals had a low sensitivity, but a good specificity. Basophil histamine release and immunoblot showed low sensitivity and specificity. A combination of clinical history and skin prick test should be used in order to diagnose latex allergy, except in those subjects reporting life-threatening reactions, in which in vitro specific IgE determination must be preferred. Patch testing with rubber chemicals should be reserved to selected cases. Basophil histamine release and immunoblotting can be performed for research purpose, but cannot be recommended for routine diagnostic use.     

Efficiency of diagnosis of latex allergy by the combined use of three latex materials for prick-tests

The diagnosis of latex allergy is mainly based on prick-tests. In order to improve the efficiency of the diagnosis, a comparative study of three latex materials is carried out in 64 controls and 29 patients allergic to latex = Stallergènes and Allerbio extracts, prepared from crude natural latex, and an ammoniated emulsion of rubber latex (AEL). No adverse reactions are recorded. The specificity is 100% for both extracts, 85% for AEL. Sensitivity is respectively 68%, 63%, 72%. The range of values of the wheal is significantly narrower for Stallergènes extract. 46% of allergic patients are reactive to the three materials. The combined use of three materials reaches an 80% efficiency similar to that of Rast Cap System and the addition of three prick-tests and Rast obtains an efficiency of 93.1%. Using several latex materials could increase the efficiency of the diagnosis, inasmuch as the extracts are generated from natural latex, whereas patients are sensitized to manufactured products originating from ammoniated latex.     

Allergie au latex : pertinence des mesures d’éviction

Complete latex avoidance is the most effective approach for treatment of latex allergy. Alternatives to latex gloves and other articles include chemical processes as well as synthetic rubber or other synthetic materials. These may be suited for certain uses only, depending on their respective physical properties. Global preventive strategies are based on current knowledge and a common-sense approach to minimizing latex allergy. Undue latex exposure should be reduced by the use of non-latex materials when there is little potential for contact with infectious agents. When latex is required, reduced-protein, powder-free latex gloves must be chosen. Education and information programs, improvement of ventilation procedures, frequent cleaning of contaminated areas, and training devices about latex allergy are usually recommended. However, detection of high-risk patients or workers must be discussed in relation to the background.     

Natural rubber latex allergy and asthma

Allergic responses to natural rubber latex (NRL) continue to be reported. In adults, the major exposure is in the occupational setting, especially in relation to NRL glove use by health care workers. Issues addressed over the past year include improving diagnostic methods for NRL allergy and characterization of NRL allergens relevant to various exposure groups and evaluating strategies for prevention and early detection of NRL allergy. Assessment of in vitro tests show good intertest correlation but lower sensitivity compared with skin test responses. NRL allergens have been further characterized as reported in the past year. Development of recombinant Hev b 3, a major NRL allergen relevant to children with spina bifida, enhances the likelihood for improved diagnostic reagents. Preliminary reports of primary preventive strategies suggest that avoidance of high-protein, powdered gloves in health care facilities can be cost-effective and is associated with a decline in sensitized workers.     

Latex allergen sensitization and risk factors due to glove use by health care workers at public health units in Florianopolis, Brazil.

BACKGROUND: Natural rubber latex allergy is a "new" illness whose prevalence has reached epidemic proportions in highly exposed populations such as health care professionals. OBJECTIVE: The aim of the study was to evaluate the frequency of reactions to latex and risk factors due to glove use in health care workers (HCW) in Florianopolis, Santa Catarina, Brazil. METHODS: We evaluated latex-related allergy in 260 HCW by means of a questionnaire, skin prick tests (SPT) and serum latex specific IgE antibody levels. The subjects were divided into two groups depending on level of exposure to latex gloves. Comparisons were made between the different variables and a risk score was calculated using logistic regression analysis. RESULTS: Glove-related symptoms were observed in 57% of 140 HCW. Significant differences between HCW and control groups were found for the following symptoms: contact dermatitis (P < .0001), cutaneous rash (P < .0001), asthma or allergic rhinitis (P < .0001), symptoms associated with toy balloons (P < .0001), airborne glove powder causing latex allergen reaction (P < .0001), food allergy (P < .0001), fruit allergy (P < .0001) and multiple surgical interventions (P = .0052). Contact dermatitis and anaphylaxis were the main problems, with a high risk factor for the development of latex allergy. Logistic regression analysis showed a significant positive association between the risk of latex allergy and those subjects who reported more than 4 positive answers on the questionnaire (including SPT) (odds ratio 6.8; 95% confidence interval 0.7-60.3). No latex-related allergy symptoms were reported by the control group. Serological latex specific immunoglobulin (Ig) E antibody levels were negative for both groups. CONCLUSION: It is essential to recognize which professionals are sensitized to latex in order to provide appropriate treatment and to establish adequate prevention.     

Prevalence of latex allergy and evaluation of some risk factors in a population of atopic children.

The aims of our study were to evaluate (1) the prevalence of natural rubber latex (NRL) allergy in an unselected population of atopic children; (2) the diagnostic efficacy of skin prick tests (SPTs) with latex extracts; (3) the correlation between positive SPTs to latex and risk factors such as atopy, fruit allergy, history of surgery cares or dental cares. We randomly enrolled 151 unselected atopic and 59 nonatopic children who underwent SPTs with common inhalant and food allergens, and SPTs with two different latex extracts. A clinical history concerning allergic history, symptoms after contact with latex objects or after ingestion of fruits or vegetables, dental and surgical treatments was obtained. Six of the 151 atopic children were positive to latex SPTs, but only one out of 59 nonatopic children was positive to latex SPTs. Concerning risk factors, 86% of children with SPT positive to latex were atopic, 71.4% had a clinical history of surgery, and none of them had undergone dental or orthodontic treatments. The prevalence of NRL sensitization in our unselected population of atopic children was 3.9%, but the prevalence of NRL allergy was 2.6%. Concerning NRL allergy, the sensitivity and the specificity of SPTs with latex extracts are high (1.00 and 0.98, respectively), as well as negative predicting value (1.00); the positive predictive value is low (0.70). We conclude that atopy, surgical treatments, and sensitization to foods cross-reacting with NRL are important risk factors for NRL sensitization. We have no data concerning dental or orthodontic cares.     

The basophil activation test in the diagnosis of anaesthesia-related allergy

This review intends to summarise on the application of the basophil activation test (BAT) in the diagnostic management of anaesthesia-related allergy. The BAT relies upon flow cytometric quantification of alterations of particular basophilic activation markers. In the context of anaesthesia-related allergy the technique has been applied and proven reliable to diagnose IgE-mediated allergy from drugs (e.g., neuromuscular blocking agents, β-lactam antibiotics), natural rubber latex, chlorhexidine, plasma expanders and dyes. Moreover, the technique has proven to be complementary to skin tests in the assessment of cross-reactivity and tailoring safe alternative regimens for future anaesthesia.     

Latex allergy: Review of recent advances

Latex allergy is an IgE-dependent immediate hypersensitivity reaction to latex proteins. Risk factors for latex allergy are contact with latex products and atopy. Children who undergo multiple surgical procedures and healthcare workers are the major groups at risk. Powdered latex gloves are an important source of sensitization. Preventive measures are leading to reduction in latex sensitization and allergic reactions. The prevalence of latex allergy in the general population may be as low as 0.1%, whereas the frequency of latex sensitization is reported to be 7%; this may be due to cross-reacting antipollen IgE. The most important latex allergens have been purified, and some have been cloned and sequenced. Many latex-allergic patients are also allergic to common plant-derived aeroallergens and foods. The structural and biologic relationships among plant-derived food allergens, including latex, explain these clinically important cross-reactions.     

Screening for latex sensitization by questionnaire: diagnostic performance in health care workers.

BACKGROUND: Latex allergy has emerged as a major cause of allergic reactions in health care workers. However, information is limited regarding the diagnostic methods available. OBJECTIVE: The aim of this study was to investigate diagnostic performance (sensitivity, specificity, and predictive values) of screening for natural rubber latex sensitization by questionnaire among health care workers, using skin prick test (SPT) as the gold standard for diagnosis. METHODS: The study population consisted of 260 randomly selected health care workers from the public health units in the city of Florianopolis, Brazil. The subjects were recruited from 2 groups: those who used latex gloves in their work (140) and those who were not exposed to latex (120). The mean (SD) age of the study population was 38.6 (0.6) years. Logistic regression analysis was used to predict SPT result from the questionnaire on previous symptoms of latex sensitization. RESULTS: Symptoms of (1) dryness, fissuring, swelling, pruritus, or cutaneous rash on the hands, and (2) pruritus of the oral mucosa or local redness after eating certain fruits (avocados, bananas, kiwis, chestnuts, mango, melons, or peaches) were the most sensitive and specific questionnaire items, respectively. The combination of these items with a cutoff point derived from the logistic regression led to 100% sensitivity and specificity for the prediction of SPT results in the population studied, with 95% confidence intervals of 51.7% to 100% for sensitivity and 98.1% to 100% for specificity. CONCLUSION: A questionnaire applied in a group of health care workers displayed excellent screening performance for latex sensitization.     

Minimum prevalence of latex hypersensitivity in health care workers.

Health care workers (HCW) have been shown to be at significant risk for developing latex allergy. Natural rubber latex hypersensitivity has been reported in 2.9 to 17% of health care workers in previously published studies. This study describes the prevalence of latex hypersensitivity in a large cohort of medical center employees. A screening questionnaire was distributed to 1967 employees in six job categories exposed to latex, and 1331 questionnaires were returned (68%) between March and November 1995. Skin and serologic testing was performed on 156 volunteers. Of the 1331 HCWs who completed the screening questionnaire, 290 (21.8%) self-reported contact dermatitis to latex, 67 (5.0%) self-reported urticaria to latex, 163 (12.2%) self-reported rhinoconjunctivitis to latex, and 17 (1.3%) self-reported asthmatic symptoms to latex. Of the total population of 1967 employees, 38 (1.9%) were either skin test or blood test positive and 30 (1.5%) of these 38 were symptomatic around latex. This study suggests a minimum prevalence of IgE-mediated hypersensitivity to latex of 1.5% among medical center employees. Our reported prevalence figures are lower than previously reported, reflecting, in part, reporting methods using a denominator more consistent with the total population at risk. Our study also illustrates the pitfall of relying on self-reporting in making the diagnosis of latex allergy.