Anaphylaxis associated with latex allergy during barium enema examinations

Anaphylaxis and urticaria

Anaphylaxis and urticaria are common presenting allergic complaints. Affecting up to 2% of the population, anaphylaxis is a serious, life-threatening allergic reaction. Although not life-threatening, urticaria is a rash of transient, erythematous, pruritic wheals that can be bothersome and affects up to 25% of the population. All cases of anaphylaxis warrant thorough clinical evaluation by the allergist-immunologist, although most cases of urticaria are self-limited and do not require specialist referral. This article offers an overview of our current knowledge on the epidemiology, pathogenesis, triggers, diagnosis, and treatment of anaphylaxis and urticaria.

Primary prevention of latex allergy in healthcare-spectrum of strategies including the European glove standardization

IgE-mediated allergy to natural rubber latex was first noted from rubber gloves in 1979. The initial reports in dermatological journals described contact urticarial reactions; later, severe generalized allergic reactions and asthma were documented. A considerable proportion of the people involved in medical and dental care were found to be sensitized to latex. This article describes and surveys a broad range of primary prevention measures at the local and national levels. Examples are given from paediatrics, dental education, and medical care. National strategies and position papers on latex allergy are presented in which medical professionals, manufacturers and public authorities have cooperated. Special reference is paid to the European work to standardize medical gloves, which led to document EN 455:3.

Latex medical gloves: time for a reappraisal

Many hospitals have implemented policies to restrict or ban the use of devices made of natural rubber latex (NRL) in healthcare as precautionary measures against the perceived risk of NRL allergy. Changes in glove technology, progress in measuring the specific allergenic potential of gloves and a dramatic decrease in the prevalence of NRL allergies after interventions and education prompted us to revisit the basis for justifiable glove selection policies. The published Anglophone literature from 1990 to 2010 was reviewed for original articles and reviews dealing with the barrier and performance properties of NRL and synthetic gloves and the role of glove powder. The review shows that NRL medical gloves, when compared with synthetic gloves, tend to be stronger, more flexible and better accepted by clinicians. The introduction of powder-free gloves has been associated with reductions in protein content and associated allergies. Recently, new methods to quantify clinically relevant NRL allergens have enabled the identification of gloves with low allergenic potential. The use of low-protein, low-allergenic, powder-free gloves is associated with a significant decrease in the prevalence of type I allergic reactions to NRL among healthcare workers. Given the excellent barrier properties and operating characteristics, dramatically reduced incidences of allergic reactions, availability of specific tests for selection of low-allergen gloves, competitive costs and low environmental impact, the use of NRL gloves within the hospital environment warrants reappraisal.

Latex anaphylaxis caused by a Swan-Ganz catheter

A 78-year-old woman visited the division of cardiovascular disease in our hospital. She underwent a cardiac catheter examination, and a Swan-Ganz catheter was inserted. Several minutes later, she developed anaphylactic shock. She had no past history of latex allergy, but did have a banana allergy. Skin prick tests showed a positive reaction to an extract of latex gloves and an extract of the balloon of a Swan-Ganz catheter. Anaphylactic shock caused by the latex balloon of a Swan-Ganz catheter was diagnosed. It is necessary to pay attention to not only latex allergy but also fruit allergies with a cross-reactivity to latex.

Risk factors for latex sensitization in young children with myelomeningocele. Clinical article

OBJECT

Patients with myelomeningoceles (MMCs) are at increased risk of latex allergy and sensitization. Number of surgeries and history of atopy are known risk factors. The object of this study was to evaluate the role of diagnostic procedures and nonsurgical treatments in latex sensitization in young patients with MMC.

METHODS

Seventy-three children with MMC were included in the study. For each child a questionnaire was administered and serum determination of IgE was performed, and 62 children underwent skin prick tests (SPTs), 60 of which had reliable results. Multivariate logistic regression modeling was performed, using latex sensitization as the dependent variable.

RESULTS

The mean age of the 73 patients was 3.8 years. The SPT results were positive in 30.6%, whereas results of testing for latex-specific IgE were positive in only 8.2%. In univariate analysis, history of untethering, barium enema, and number of clean intermittent catheterizations (CICs) per day were significantly associated with positive results on the SPT. Although the number of surgical procedures was significantly higher in patients who had shunts, no significant relationship between the presence of a shunt and latex sensitization was seen.

CONCLUSIONS

The young age of the patients in this study may account for the low prevalence of latex sensitization that was found. In young patients with MMC, the numbers of CICs per day, a history of untethering, circumcision, and a barium enema performed without latex-free equipment could be risk factors for latex sensitization. The use of latex-free gloves in all procedures performed in these cases, nonlatex polyvinyl chloride catheters in CIC, and ordinary nonballoon tips in barium enemas could decrease the risk of sensitization.

Anaphylaxis: Drug Allergy, Insect Stings, and Latex

The highest rates of anaphylaxis in humans occur in early childhood associated with food allergy. Latex allergy, pharmaceutical drugs, and stinging insect reactions are important later in childhood, with drug allergy peaking in adult populations. Knowledge about diagnosis and therapy of anaphylaxis is critical, because a large percentage of subjects are not previously known to be at risk at the time of initial reactions. This article summarizes the basic clinical knowledge of anaphylaxis in childhood.

Epidemiology of life-threatening and lethal anaphylaxis: a review

Severe anaphylaxis is a systemic reaction affecting two or more organs or systems and is due to the release of active mediators from mast cells and basophils. A four-grade classification routinely places 'severe' anaphylaxis in grades 3 and 4 (death could be graded as grade 5). Studies are underway to determine the prevalence of severe and lethal anaphylaxis in different populations and the relative frequencies of food, drug, latex and Hymenoptera anaphylaxis. These studies will also analyse the risk arising from the lack of preventive measures applied in schools (personalized management protocols) and from the insufficient use of self-injected adrenalin. Allergy-related conditions may account for 0.2-1% of emergency consultations. Severe anaphylaxis affects 1-3 per 10 000 people, but for the United States and Australia figures are even higher. It is estimated to cause death in 0.65-2% of patients, i.e. 1-3 per million people. An increased prevalence has been revealed by monitoring hospitalized populations by reference to the international classification of disease (ICD) codes. The relative frequency of aetiological factors of allergy (food, drugs, insects and latex) varies in different studies. Food, drug and Hymenoptera allergies are potentially lethal. The risk of food-mediated anaphylaxis can be assessed from the number of personalized management protocols in French schools: 0.065%. Another means of assessment may be the rate of adrenalin prescriptions. However, an overestimation of the anaphylaxis risk may result from this method (0.95% of Canadian children). Data from the literature leads to several possibilities. First, a definition of severe anaphylaxis should be agreed. Secondly, prospective, multicentre enquiries, using ICD codes, should be implemented. Moreover, the high number of anaphylaxis cases for which the aetiology is not identified, and the variation in aetiology in the published series, indicate that a closer cooperation between emergency specialists and allergists is essential.

Characterization of a mouse model of allergy to a major occupational latex glove allergen Hev b 5

Allergen-specific immunotherapy is a clinically proven effective treatment for many allergic diseases, including asthma; however, it is not currently available for latex allergy because of the high risk of anaphylaxis. There is, therefore, a crucial need for an animal model of latex allergy in which to develop effective immunotherapy. Previous mouse models of latex allergy either did not characterize the allergic pulmonary immune response or used crude latex extracts, making it difficult to quantify the contribution of individual proteins and limiting their usefulness for developing specific immunotherapy. We immunized mice with recombinant Hev b 5, a defined major latex allergen, or latex glove protein extract, representing the range of occupationally encountered processed latex allergens. The immune response was compared with that seen in ovalbumin-immunized mice. Immunization with Hev b 5 or glove extract elicits hallmarks of allergic pulmonary Th2-type immune responses, comparable to those for ovalbumin, including (1) serum antigen-specific IgE, (2) an eosinophilic inflammatory infiltrate in the lung, (3) increased interleukin-5 in lung bronchoalveolar lavage fluid, and (4) mucus hypersecretion by epithelial cells in the lung airways. This mouse model will aid the development of potentially curative treatments for latex-sensitized individuals, including those with occupational asthma.

Occupational allergies caused by latex

Allergy to natural rubber latex is an important cause of occupational allergy in healthcare workers. Disposable medical gloves are the major reservoir of latex allergens, particularly powdered gloves, in healthcare delivery settings. Diagnosis of latex allergy requires a history of exacerbation of cutaneous, respiratory, ocular, or systemic signs and symptoms after exposure to natural rubber latex products; and evidence of sensitization by patch testing, skin testing, measurement of latex-specific IgE antibodies, or challenge testing. Optimal management of latex allergy involves education concerning cross-reacting allergens, reduction of cutaneous or mucosal contact with dipped rubber products, and minimization of exposure to latex aeroallergens in work environments.

The prevalence of latex-specific IgE in patients presenting to an urban emergency department

STUDY OBJECTIVE

Since the first report of immediate hypersensitivity to latex was documented in 1979, latex allergy has been increasingly recognized as a medical problem in patient populations. However, there are no data available regarding the seroprevalence of latex sensitization in patients presenting to the emergency department. The overall aim of this study was to determine the prevalence of latex IgE seropositivity (L-IgE) in ED patients.

METHODS

We measured latex-specific IgE antibodies among a convenience sample of 1,027 patients using the AlaSTAT assay. We also measured serum IgE antibodies specific for 12 common inhalant allergens using the AlaTOP Microplate Allergy Screen assay. Demographic data were collected. Two questions related to latex allergy were queried. Descriptive statistics are presented. Point estimates and 95% confidence intervals (CIs) were calculated for each seroprevalence test. Odds ratios (ORs) and 95% CIs were used to assess the relationship between sex, race, and seropositivity to inhalant allergens and L-IgE.

RESULTS

The participation rate was 90% (1,027). The mean age of the patients was 46.9 years, 47.6% (489) were male, and 13.9% (143) were white. Eighty-four (8.2%; 95% CI 6.5% to 10.0%) had positive L-IgE results, and 23.8% (20) of patients with positive L-IgE results were classified as having strongly positive results. Bivariate analyses showed that being nonwhite (OR 4.7; 95% CI 1.5 to 15.1) and being seropositive for inhalant allergens (OR 7.4; 95% CI 4.2 to 13.1) were associated with L-IgE.

CONCLUSION

The prevalence of latex sensitization in our sampling is substantial and higher than previously estimated in the general adult population. The clinical significance of seropositivity requires further evaluation.

HLA-DQ8 and the HLA-DQ8-DR4 haplotype are positively associated with the hevein-specific IgE immune response in health care workers with latex allergy

BACKGROUND

Hevein is one of the most important latex allergens affecting health care workers (HCWs).

OBJECTIVE

Because the genetically determined susceptibility is one important factor regulating type I allergy, the association between the hevein-specific IgE immune response and HLA class II alleles of DQB1 and DRB1, DRB3, DRB4, and DRB5 was studied.

METHODS

The distribution of HLA-DQB1 and DRB1, DRB3, DRB4, and DRB5 in 269 HCWs with latex allergy, 56 latex-sensitized patients with spina bifida (SB), and 90 nonatopic control subjects under special consideration for hevein-specific IgE was examined.

RESULTS

Seventy percent (189/269) of the HCWs with latex allergy and 39% (22/56) of the latex-sensitized patients with SB had increased hevein-specific IgE antibody concentrations (>0.35 kU/L). HLA data analysis revealed significantly increased phenotype frequencies for DQB1*0302 (DQ8; 91/189 [48%]) and DRB1*04 (DR4; 102/189 [54%]) in hevein-positive HCWs with latex allergy compared with the 80 hevein-negative HCWs with latex allergy (DQB1*0302: 16/80 [20%], corrected P value [P (c)] = 7.1 x 10(-4); DRB1*04: 23/80 [29%], P (c) =.01) and with control subjects (DQB1*0302: 16/89 [18%], P (c) = 1 x 10(-4); DRB1*04: 22/90 [24%], P (c) = 3.2 x 10(-4)). The DQ8-DR4 haplotype frequency was significantly elevated in HCWs with hevein-specific IgE antibodies when compared with that in HCWs without hevein-specific IgE antibodies (47% vs 18%, P (c) = 5.3 x 10(-4)) or control subjects (47% vs 18%, P (c) = 9.6 x 10(-4)). In contrast, latex-sensitized patients with SB with hevein-specific IgE antibodies showed an increased but not significant DQB1*0302 frequency (7/22 [32%] vs 2/34 [6%], P =.02, P (c) = not significant) compared with that seen in those without hevein-specific IgE antibodies.

CONCLUSION

The DQB1*0302 (DQ8) alone, the DQB1*0302 (DQ8)-DRB1*04 (DR4) haplotype, or both are significantly involved in the hevein-specific IgE immune response in HCWs with latex allergy.

A history of latex allergy

Archaeologists have found that latex items were used as early as 1600 BC, but it took until approximately 1900 AD before surgical gloves were commonly used. Descriptions of apparent allergic reactions to natural rubber appeared in the medical literature in 1927, and irritant and delayed-contact reactions were reported in 1933. Although irritant and delayed-contact reactions to rubber products were increasingly recognized, immediate-type allergic reactions were not reported again until 1979. However, after 1980, increasing numbers of contact urticarial reactions to latex were reported, and investigations suggested that many of these reactions were IgE-mediated. In 1984, the first anaphylactic reactions caused by latex surgical gloves were reported, followed in 1991 by the first report of a fatal anaphylactic reaction to latex. Increasing recognition of latex allergy led to divergent paths of investigation. Critical early questions were whether the observed reactions were truly IgE-mediated, and if they were IgE-mediated, what was the source of the allergen? If the allergen was present in latex products, where did it come from? Was it present in raw latex or was it added during processing? As knowledge about the allergens improved, efforts were made to develop and test materials for skin testing and for allergen-specific IgE assays. Now more than 10 unique proteins are recognized as major latex allergens. Although much has been learned about latex allergy, important unanswered questions remain, including the sources of latex exposure that led to sensitization, why latex allergy increased dramatically during the 1980s, and the prevalence of latex allergy in diverse populations. This review concentrates on the history of latex use in medicine and the dramatic emergence of immediate-type latex allergy.

Anaphylactic reactions during surgical and medical procedures

The most common agents that are responsible for intraoperative anaphylaxis are muscle relaxants. However, latex accounts for a significant number of these reactions, and the incidence of intraoperative anaphylaxis caused by latex is increasing. It is now probably the second most important cause of intraoperative anaphylaxis. Following muscle relaxants and latex are probably antibiotics and anesthesia induction agents. Other agents that are responsible include colloids, opioids, and radiocontrast material. However, they account for less than 10% of all reactions. The clinical manifestations of intraoperative reactions differ from those of anaphylactic reactions outside of anesthesia. Cutaneous manifestations are far less common; cardiovascular collapse may be more common. The diagnosis can be made more difficult because patients cannot express symptoms. There is a paucity of cutaneous findings; the patient is draped, and concomitantly administered drugs may alter the manifestations. These additional drugs can also complicate therapy. There are populations who are at-risk for anaphylaxis to latex during surgical procedures: individuals with a genetic predisposition (atopic individuals), individuals with increased previous exposure to latex (eg, anyone who requires chronic bladder care with repeated insertion of latex catheters or chronic indwelling catheters), health care workers who are exposed to latex mainly by inhalation, and possibly patients who have undergone multiple surgical procedures and therefore have been exposed to latex intravascularly and by catheterization on a number of occasions. It has been shown that pretreatment with antihistamines and corticosteroids that are used successfully for the prevention of reactions to radiocontrast material are not as effective in the prevention of anaphylactic reactions to latex. Therefore, the major emphasis has been on prevention. The key elements of prevention include an adequate history, testing for latex allergy in high-risk patients, preadmission measures, and the establishment of a "latex-free environment" while the individual is hospitalized. This is particularly important in the operating and recovery rooms.

Allergic reactions to natural rubber latex at home, to rubber products, and to cross-reacting foods

The prevalence of clinical sensitivity to natural rubber latex (NRL) has increased dramatically in the last 15 years. In the health care setting this has been associated with the increased use of latex gloves. It does not, however, explain the observation that IgE antibodies to NRL are detected in equal rates in both health care workers and the general population, with the numerous reactions occurring in homes and in health care settings in non-health care workers. This increase in NRL sensitivity has occurred at the same time as our observation of an increase in atopy. In addition, atopy is a definite risk factor that has been associated with NRL sensitivity in all studies. Exposure to NRL products outside the health care environment is significant and ubiquitous. Exposure to NRL epitopes also occurs by ingestion of foods, food additives, and pollen. This exposure is sufficient to induce IgE antibodies to both the food and NRL proteins. It is therefore difficult in an individual patient to implicate any single product as the cause of NRL sensitization leading to the development of symptoms. Outside of the health care environment there does not appear to be an increase in exposure to NRL products or to cross-reacting materials. This would suggest that there is an increase in the susceptible population, which clearly appears to be the atopic individual. A great deal of attention is devoted to reducing exposure to latex gloves in the health care setting, which may be only the visible portion of the iceberg. More attention should be devoted to reducing the antigens present in all NRL products and consideration given to developing vaccines for the food-sensitive individuals.

Allergens and natural rubber proteins

BACKGROUND

Allergy to natural rubber latex (NRL) results from exposure to proteins derived from Hevea brasiliensis. Type I latex hypersensitivity is observed in certain occupational and other high-risk groups with frequent exposure to NRL products. This includes health care workers (HCWs), workers in the latex industry, children with spina bifida, and atopic individuals.

OBJECTIVES

Early reliable diagnosis and avoidance are required for better patient care. Standardized reagents are not presently available for in vitro and in vivo testing and treatment of patients with latex allergy. However, a number of allergens have been isolated and characterized from Hevea latex and NRL products. Currently, a total of 11 major and minor allergens are designated by the International Allergen Nomenclature Committee. This article reviews the structural and functional characteristics of these latex allergenic proteins.

RESULTS

NRL-allergenic proteins include those involved in the biosynthesis of polyisoprene and coagulation of latex rubber elongation factor, small rubber particle protein, prohevein, and patatin. Pathogenesis-related proteins include beta-1,3-glucanases, chitinases, and hevamine; and the structural proteins include microhelix protein complex, proline-rich protein, profilins, enolases, and manganese superoxide dismutase. Recombinant allergens demonstrated skin test reactivity in patients with latex allergy. The minimal level of skin test reactivity was about 70 pg/mL for NRL and 1 ng/mL for recombinant allergens. The use of selected recombinant latex allergens (Hev b 5, Hev b 6, and Hev b 7) in skin prick tests identified 93% of allergic individuals, mainly health care workers.

CONCLUSIONS

Recombinant latex allergens are clinically reactive and can be produced in a standardized manner, which could potentially provide safe and sensitive reagents for the diagnosis and treatment of type I latex allergy.

Latex allergy: towards immunotherapy for health care workers

Latex allergy is an important allergic disease for which safe and readily available immunotherapy is currently lacking. Despite advances in latex glove technology and reduction in allergen content, there remains a core of severely allergic health care workers (HCW), particularly with concominant food allergy, for whom allergen avoidance is insufficient. Current experience with immunotherapy using crude latex extracts has shown an unacceptable level of local and systemic side-effects. Latex allergens are extremely potent with a heightened capacity to cross-link effector cell-bound IgE and induce anaphylaxis. The predominant pattern of allergen reactivity among HCW is different from that among children with spina bifida, perhaps due to exposure to latex glove proteins, particularly via inhalation, rather than particle bound latex proteins present in urinary catheters. Recent studies using purified skin testing reagents have indicated that the most clinically important latex allergens amongst HCW are Hev b 5, 6 and 7. Elucidation of the molecular and cellular mechanisms of the immune response to these allergens is pivotal to facilitate the search for safer immunotherapy of latex allergy among HCW.

Latex allergy: historical perspective

The widespread use of powdered latex gloves, following the institution of universal precautions in 1987, increased the occurrence of a host of adverse reactions to natural rubber latex (NRL). Although the most common reactions are irritant or allergic dermatitis reactions to manufacturing chemicals, a spectrum of type I IgE-mediated reactions to NRL proteins are of great concern. IgE-mediated reactions range from contact urticaria to occupational asthma and anaphylaxis, resulting in significant morbidity and potential mortality. At-risk populations include highly exposed groups like health care workers and certain patient groups requiring extensive medical treatment. A significant complicating factor is the association with clinically significant adverse reactions to certain foods because of allergen cross-reactivity. Institution of policies to use only low-protein, powder-free gloves, has resulted in a dramatic reduction of visits to occupational health departments and workmen's compensation claims due to occupational asthma.

Latex allergy desensitization by exposure protocol: five case reports

Two clinical reports dealing with subcutaneous desensitization to latex are available, but these treatments were reported to have significant side effects. To investigate an alternative method for latex desensitization, we present five cases of immunoglobulin E-mediated latex allergy in which a specific desensitization was successfully performed by means of an original exposure protocol. Five female patients with proven latex allergy underwent an original contact desensitization by wearing latex gloves daily, progressively increasing exposure to latex. All patients reached a final latex exposure time of 60 min in both hands. The desensitization protocol was completely successful in all patients. Twelve months after the beginning of the desensitization program, all the treated subjects were able to wear latex gloves daily without any clinical manifestations. This study provides evidence that a successful contact desensitization to latex is possible with no side effects. The adopted exposure protocol seems to be completely safe and effective. However, further studies in larger groups of subjects are necessary to fully confirm these preliminary results.

IMPLICATIONS

We present five patients with latex allergy who underwent desensitization by a new cutaneous exposure protocol. This study provides evidence that a safe therapeutic approach to latex allergy is possible.

Natural rubber latex allergy after 12 years: recommendations and perspectives

Natural rubber latex (NRL) allergy is a "new" illness whose prevalence reached epidemic proportions in highly exposed populations during the last decade. In children with spina bifida and in patients exposed to NRL during radiologic procedures, institution of prophylactic safety measures has had demonstrable effects in preventing allergic reactions. The risk of NRL allergy appears to be largely linked to occupational exposure, and NRL-associated occupational asthma is due almost solely to powdered latex glove use. Prevalence of NRL-allergic sensitization in the general population is quite low; several studies of young adults demonstrate rates of positive skin test results that are less than 1%. After occupational exposure, rates of sensitization and NRL-induced asthma rise dramatically in individuals using powdered NRL gloves but not in individuals using powder-free gloves. Airborne NRL is dependent on the use of powdered NRL gloves; conversion to non-NRL or nonpowdered NRL substitutes results in predictable rapid disappearance of detectable levels of aeroallergen. For these reasons, adoption of the following institutional policies designed to prevent new cases of NRL allergy and maximize safety is recommended: (1) NRL gloves should be used only as mandated by accepted Standard Precautions; (2) only nonpowdered, nonsterile NRL gloves should be used; and (3) nonpowdered, sterile NRL gloves are preferred for use. Low-protein powdered, sterile gloves may be used, but only in conjunction with an ongoing assessment for development of allergic reactions.

Risk factors for latex sensitization in children with spina bifida

BACKGROUND

Children with spina bifida represent the major risk group for latex sensitization.

PURPOSE

To determine the prevalence of latex sensitization in these children and to identify risk factors.

MATERIAL AND METHODS

We studied 57 patients with spina bifida. The mean age was 5.6 years and the male/female ratio was 0.8/1. In all patients a questionnaire, skin prick test (SPT) with latex (UCB-Stallergènes, Lofarma and ALK-Abelló), common aeroallergens and fruits (UCB-Stallergènes) and serum determination of total IgE (AlaSTAT) were performed.

RESULTS

The prevalence of latex sensitization was 30 %; only two sensitized children (12 %) had symptoms after exposure. Risk factors for latex sensitization were age >/= 5 years (p = 0.008; OR = 6.0; 95 % CI = 1.7-22.1), having at least four previous surgical interventions (p < 0.0001; OR = 18.5; 95 % CI = 3.6-94.8), having undergone surgery in the first 3 months of life (p = 0.008; OR = 5.4; 95 % CI = 0.7-29.2) and total serum IgE >/= 44 IU/ml (p = 0.03; OR = 3.8; 95 %CI = 1.1-13.1). Multiple logistic regression analysis showed that only a history of four or more surgical interventions (p < 0.0001; OR = 26.3; 95 %CI = 2.9-234.2) and total serum IgE >/= 44 IU/ml (p = 0.02; OR = 8.6; 95 % CI = 1.4-53.4) were independently associated with latex sensitization. Sex, family and personal allergic history, hydrocephalus with ventriculoperitoneal shunt, cystourethrograms, intermittent bladder catheterization and atopy were not related to latex sensitization.

CONCLUSIONS

In children with spina bifida, significant and independent risk factors identified for latex sensitization were multiple interventions and higher levels of total serum IgE. A prospective study will clarify the clinical evolution of assymptomatic children sensitized to latex.

[Latex allergy. Diagnosis and therapeutic aspects]

In the last two decades of the 20th century, latex allergy has reached epidemic proportions. Epidemiological studies demonstrate that 3-25 % of health personnel is allergic to latex. The main risk groups are health workers, machine operators in latex factories, and children with spina bifida and urogenital anomalies. From the allergenic point of view, latex contains 240 peptides but approximately 50 are able to react to IgE. Latex elongation factor Hevdl is the relevant allergen in patients with spina bifida. Prohevein (hev B6) behaves as a major allergen, since it reacts to IgE in most of the sera of patients with latex allergy. The nature of latex is complex; it is an allergenic mixture that depends on chemical, immunological and epidemiological variables. Latex proteins show strong cross reactivity with several proteins from fruit and vegetable grains such as avocado, potato, banana, tomato, chestnut, and kiwi. In vivo studies have shown that class I chitinase from avocado and chestnut behave as major allergens in allergic patients with latex-fruit syndrome. The clinical manifestations related to the use of latex products depend on the type of exposure, the amount of the allergen, and individual variability. The most useful diagnostic method is the skin prick test. Several perioperative guidelines are recommended in patients sensitized to latex as well as various alternatives to rubber gloves. An increasing number of studies describe the efficacy of etiological treatment (immunotherapy), using different guidelines and routes of administration. These preliminary data encourage the hope that in the near future immunomodulatory therapy will be available to mitigate against the latex allergy epidemic.

Frequency of natural rubber latex allergy in adults is increased after multiple operative procedures

BACKGROUND

It has been shown that immediate-type allergy to natural rubber latex (NRL) affects predominantly health-care workers and infants with malformations requiring repeated medical procedures. Adult patients with multiple invasive procedures are not thought to be at an increased risk of NRL allergy.

METHODS

A total of 325 consecutive adult inpatients (54.4+/-15.6 years; 219 men, 106 women) awaiting surgical or urologic procedures were assessed by questionnaire-based history (atopic diseases, number of previous standard operative or endoscopic procedures, intolerance to rubber products, and adverse reactions during medical care), by skin prick tests with different NRL test solutions, by measurement of NRL-specific IgE in the serum, and, if sensitization to NRL was found, by cutaneous challenge tests with NRL-containing material. Subjects were classified as sensitized to NRL if skin prick test reactions to NRL were positive or if NRL-specific IgE antibodies were found. NRL allergy was defined as NRL sensitization and immediate-type symptoms to NRL.

RESULTS

Thirty-one of 325 (9.5%) subjects were found to be sensitized to NRL, 14/285 (4.9%) by skin prick testing and 23/323 (7.1%) by NRL-specific IgE antibodies in the serum. Four individuals (1.2%) were diagnosed as having clinically manifest NRL allergy, and another 27 (8.3%) were sensitized to NRL without symptoms to date. The frequency of previous invasive procedures was zero in eight patients, up to 10 in 245, 11-20 in 52, 21-30 in seven, and over 30 (up to 83) in 13 patients. No association was found between the number of invasive procedures and NRL sensitization without clinical symptoms. However, 3/4 patients with NRL allergy had undergone more than 30 interventions, and 1/4 had had 11 operations. Frequent invasive procedures (more than 10) were significantly associated with NRL allergy (P<0.001). Allergy or sensitization to NRL was associated with atopy (21/31 vs 87/294) (P<0.001).

CONCLUSIONS

A remarkable percentage of unselected adult patients undergoing surgical procedures have allergy or sensitization to NRL. Repeated invasive treatment appears to be a risk factor for NRL allergy.

Comprehensive analysis of 28 patients with latex allergy and prevalence of latex sensitization among hospital personnel

Recently anaphylactic shock caused by latex gloves and medical instruments has been discussed as an important problem in surgical operations. Patients with contact urticaria or anaphylaxis due to natural rubber latex were first reported in Japan in 1993, and the number of cases is gradually increasing. In the present study, we analyzed 28 patients examined in our clinic from 1993 to 1998. The diagnosis of latex allergy was made on the basis of clinical history, latex specific IgE antibody, skin test, and use test. The 3 male and 25 female patients included 20 nurses, 4 doctors, 2 housewives, one animal hospital employee, and one worker in a senile rehabilitation center. The majority were health care workers. Contact urticaria from rubber gloves was the most common clinical symptom. Some of the patients developed severe attacks of anaphylaxis. During the period from 1995 to 1997, we also performed a questionnaire study and a serum examination of latex specific IgE antibody among the personnel of our university hospital. The screening test for the antibody was more reliable than our questionnaire study in detecting latex-sensitive persons. The prevalence of latex allergy was found to be 4.6%. This indicates that not only dermatologists but also all hospital workers should be aware of this type of allergy.

Anaphylactic Shock from a Latex Allergy in a Patient with Spinal Trauma

Allergy to latex is a condition that affects patients as well as health care workers. It is a spectrum of immunologic disorders that ranges from mild hypersensitivity to life-threatening anaphylaxis. Beginning in the early 1970s, the health care community has become more aware of this entity, leading to many improvements in the understanding, diagnosis and treatment of patients with latex allergy. Many hospitals have developed protocols and procedures for patients with latex sensitivity. However, some physicians remain unaware of the logistics of taking care of patients with this disorder. We present a case of a severe anaphylactic reaction to latex in a trauma patient with a spinal cord injury. The difficulty of treating the acutely injured patient with this disorder is illustrated. A list of equipment that may be included in a latex-free emergency kit is provided.

Human T-cell epitopes of the latex allergen Hev b 5 in health care workers

BACKGROUND

Latex allergy affects health care workers as a high-risk cohort. Hev b 5 is a major latex allergen reacting with serum IgE from 92% of latex-allergic health care workers. Because CD4(+) T-cell recognition is central to the specific immune response to allergens, identification of dominant T-cell epitopes is important for the development of specific immunotherapy for latex allergy.

OBJECTIVE

Our purpose was to map T-cell epitopes of Hev b 5 in health care workers.

METHODS

Six latex-allergic health care workers (grade 3 to 4 enzyme allergosorbent test score) were studied. Peripheral blood latex specific 3-week T-cell lines were generated and screened for proliferative response to overlapping 20-mer peptides of Hev b 5. Supernatants collected at 48 hours were analyzed by ELISA for IL-5 and IFN-gamma.

RESULTS

Dot immunoblotting with use of recombinant Hev b 5/maltose-binding protein indicated serum-specific IgE in 5 of 6 patients. T-cell reactivity to one or more Hev b 5 peptides was identified in these 5 donors, but not in the sixth. Hev b 5 (46-65) induced T-cell proliferation in all 5 donors. Hev b 5 (109-128) stimulated T cells from 3 of these patients. Proliferative responses were accompanied by substantial IL-5 secretion and minimal IFN-gamma, indicating a T(H)2-predominant cytokine profile.

CONCLUSIONS

Five of 6 latex-allergic patients demonstrated T-cell responsiveness to Hev b 5 consistent with a major T-cell reactive latex allergen. Two T-cell immunodominant regions of Hev b 5 were identified, and reactivity to these sites was associated with strong IL-5 but minimal IFN-gamma production.

Prevalence of IgE to natural rubber latex in unselected blood donors and performance characteristics of AlaSTAT testing

BACKGROUND

The prevalence of IgE to natural rubber latex (NRL) proteins in the general population remains unsettled, both because of the difficulty of obtaining an unbiased population representative of the general population of the United States and because of concerns about the reproducibility of tests for anti-latex IgE antibodies. Establishing the prevalence in the population is important toward defining the potential risks of persons entering areas where latex exposure may occur.

OBJECTIVE

The purposes of this study were to determine the prevalence of IgE to latex in a general population and to assess the performance characteristics of the AlaSTAT microtiter plate test for anti-latex IgE when performed independently by different laboratories.

METHODS

One thousand nine hundred and ninety-seven consecutive blood samples obtained from the Oklahoma Blood Institute were assayed independently in three laboratories for IgE to NRL using the FDA-approved AlaSTAT ELISA for IgE to NRL. The group consisted of 56% men and 44% women. Ninety percent were Caucasian, 4% African American, and 6% were "other."

RESULTS

The prevalence IgE to NRL between the 3 laboratories varied from 5.4% to 7.6% at the designated cut off of 0.35 kU/L. Examination of results for specific individuals demonstrated >90% agreement between the three sites with the most reproducible results at the Class II cutoff of > or =0.7 kU/L. There was no difference in the percent of positive values at the three laboratories.

CONCLUSIONS

There is good agreement between laboratories as to NRL IgE reactive and non-reactive sera using the AlaSTAT test. This report of the largest sample of blood donors confirms earlier reports as to the prevalence of IgE NRL in blood donors.

Prevalence and risk factors for latex allergy: a cross sectional study in a United Kingdom hospital

OBJECTIVES

To determine the prevalence and risk factors for symptoms related to gloves, and the relation between symptoms and immunological evidence of type 1 hypersensitivity to latex in a United Kingdom health care setting.

METHODS

A cross sectional survey was carried out among 773 employees at a British hospital. A self administered questionnaire was used to collect information about symptoms related to gloves and associated risk factors in a sample of hospital staff who were likely to use gloves at work. All of those who reported symptoms suggestive of type 1 hypersensitivity were invited for skin prick testing and measurement of specific IgE to latex (RAST).

RESULTS

Among the 372 responders, symptoms related to gloves were common, 49% reported redness or itching of the hands, 14% reported urticaria, and 6% reported chest tightness. However, the frequency of positive skin prick tests and RASTs was surprisingly low (only two subjects tested positive).

CONCLUSIONS

These findings indicate the need for caution in the interpretation of symptoms related to gloves even when they seem to suggest type 1 hypersensitivity.

Latex allergy in children: diagnosis and management

Latex allergy is an increasingly common condition, in both children and health care workers who provide care for them. Subpopulations at particular risk include children with spina bifida, children undergoing multiple surgical procedures, and health care workers in the operating theatre. Chemical additives in latex gloves can cause an irritant or allergic contact dermatitis. Latex proteins are responsible for most of the immediate IgE-mediated hypersensitivity allergic reactions. Symptoms range from rhinitis, conjunctivitis and urticaria to anaphylaxis and death. A latex-directed history is the primary method of identifying latex sensitivity, although both skin and serum testing is available and increasingly accurate. (Latex avoidance should be used in all individuals with a positive skin or blood test or a positive history). The most important preventive measure for patients with or at risk for latex allergy is minimizing direct patient exposure to latex products, most notably latex gloves. Recent operating room studies indicate simple preventive measures can dramatically reduce intraoperative reactions. Preoperative prophylaxis with antihistamines and steroids have not been shown to be necessary or effective. Treatment of an allergic reaction begins with immediate removal of any identified source of latex in direct patient contact. Treatment is similar to anaphylaxis from other causes, and may require the use of epinephrine. Everyone caring for the patient at risk for latex allergy must be involved in making their medical environment safe.

The problems of rubber hypersensitivity (Types I and IV) in chronic leg ulcer and stasis eczema patients

The prevalence of Type I and Type IV hypersensitivity to rubber allergens in patients with stasis eczema and/or venous leg ulcers over an 18-month period was studied by prick and patch testing. Results from 109 patients were analysed. Positive patch tests were found in 71 patients (65%). Delayed-type hypersensitivity to rubber chemicals was found in 17 patients (15.6%). However, only 1 patient who had additional risk factors showed Type I hypersensitivity to natural rubber latex. We therefore conclude that, although Type IV hypersensitivity to rubber chemicals is relatively common in our patients, Type I hypersensitivity to natural rubber latex remains rare.

Natural rubber latex allergy

Rubber is an important industrial and consumer product encountered in many household items and medical devices. Whereas the chemical additives used in its manufacture are well recognized as a cause of delayed-type hypersensitivity (allergic contact dermatitis), it is only during the past decade that immediate-type allergy to natural rubber latex (NRL) proteins (latex allergy) has emerged as a serious health issue. Frequent, prolonged wearing of NRL gloves, especially amongst health care workers, is a major risk factor for such sensitization. Latex allergy is now an important medical, occupational, medico-legal and financial problem, and it is essential that policies are developed to reduce it. Undiagnosed latex allergy is potentially very serious for patients. This article briefly overviews latex allergy with emphasis on the practical issues of diagnosis and management.

The dental team and latex hypersensitivity. ADA Council on Scientific Affairs

BACKGROUND

In the late 1980s, there were notable increases in reports of allergic reactions to natural rubber latex, or NRL, particularly in association with barium enema procedures and medical procedures performed on children with spina bifida. These reports also raised awareness of the growing concern about NRL allergy in both patients and health care workers.

DESCRIPTION OF THE DISORDER

This report by the American Dental Association Council on Scientific Affairs summarizes the signs and symptoms of NRL protein allergy, allergic contact dermatitis and irritant dermatitis; offers information on means to diagnose these conditions definitively; and suggests means of reducing occupational exposure to the causative allergens and irritants in the dental office.

CLINICAL IMPLICATIONS

Reducing health care workers' occupational exposure may assist in minimizing adverse reactions associated with frequent wearing of gloves. The Council on Scientific Affairs will address issues relating to latex hypersensitivity among patients in a future report.

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.

Comparison of skin-prick test and specific serum IgE determination for the diagnosis of latex allergy

BACKGROUND

Latex IgE-mediated hypersensitivity has been recognized as an international health problem. However, there is poor information on the efficiency of the diagnostic methods available.

OBJECTIVE

The purpose of this study was to specify the efficiency of several diagnostic methods for latex allergy.

METHODS

We designed a prospective study involving 50 adult patients with latex allergy, as diagnosed by a suggestive clinical history and a positive skin-prick test (SPT) to a latex extract. One control group of 50 subjects paired for age, sex, total IgE levels and latex exposure, and another control group of 30 subjects with pollen allergy were used. A low-ammoniated natural-latex and several glove-latex extracts were elaborated. SPTs with these extracts, as well as with four different commercial-latex extracts were performed. Latex-specific serum IgE was determined by the CAP and the AlaSTAT methods.

RESULTS

Diagnostic sensitivity was 98% for the natural-latex extract SPT, from 90% to 98% for the commercial-latex extract SPT, and from 64% to 96% for the glove-latex extract SPT. Diagnostic specificity of SPT was 100%, and no severe adverse reactions were observed during skin testing. With respect to the latex-specific serum IgE determinations, sensitivity was 86% for the CAP system and 84% for the AlaSTAT assay, and specificity was dependent on the population considered.

CONCLUSION

SPT with natural latex extracts has shown a diagnostic efficiency close to 100%, significantly higher than that of latex-specific serum IgE determination.