Incidence of latex sensitization among latex glove users

Treating Moderate-to-Severe Allergic Asthma with a Recombinant Humanized Anti-IgE Monoclonal Antibody (Omalizumab)

Bronchial asthma is a chronic inflammatory disease of the airways which is recognized as a highly prevalent health problem in both the developed and the developing world, with significant human and economic consequences.Allergy is acknowledged as a major risk factor for asthma. The pathogenetic aspects of allergic asthma are characterized by airway inflammation with infiltration of mast cells, basophils, eosinophils, monocytes and T helper type 2 lymphocytes, along with the isotype switching of B cells to generate immunoglobulins of the immunoglobulin E (IgE) class. Increased asthma severity is not only associated with recurrent hospitalization and increased mortality but also with higher social costs.Inhaled corticosteroids are the standard anti-inflammatory medication and are effective for most asthma patients, but there is a substantial number of asthmatics who remain symptomatic even after receiving treatment with inhaled corticosteroids and long-acting beta(2)-adrenoceptor agonists (beta(2)-agonists), and sometimes are in need of systemic corticosteroids to control the disease. These patients account for about 50% of the healthcare costs of asthma.New treatment options more specifically targeting the pathophysiologic events causing development of asthma are therefore required in these patients.A novel therapeutic approach to asthma and other allergic respiratory diseases involves interference with the action of IgE and prevention of subsequent IgE-mediated responses.Omalizumab is a humanized recombinant monoclonal anti-IgE antibody developed for the treatment of allergic diseases, with clear efficacy in adolescent and adult patients with moderate-to-severe allergic asthma. This non-anaphylactogenic anti-IgE antibody inhibits IgE functions by blocking free serum IgE and inhibiting their binding to cellular receptors. Omalizumab therapy is well tolerated and significantly improves symptoms and disease control, and reduces asthma exacerbations and the need to use high dosages of inhaled corticosteroids. Moreover, omalizumab improves quality of life of patients with severe persistent allergic asthma that is inadequately controlled by currently available asthma medications. In conclusion, omalizumab may fulfill an important need in patients with moderate-to-severe asthma inadequately controlled with inhaled corticosteroids +beta(2)-agonists.

Ten years incidence of natural rubber latex sensitization and symptoms in a prospective cohort of health care workers using non-powdered latex gloves 2000-2009

OBJECTIVES

To assess the incidence of sensitization and gloves-related symptoms in 10-year follow-up in a group of health care workers (9,660 person-years) using non-powdered latex gloves from 2000 to 2009 and to examine related factors.

MATERIALS AND METHODS

We studied 2,053 health care workers in Trieste Hospitals by means of skin prick test for latex extract, patch tests and medical examinations. We report the incidence of latex sensitization among workers using non-powdered latex gloves.

RESULTS

The incidence of latex sensitization, rhinitis, asthma, urticaria, irritant and allergic contact dermatitis were 1.0; 0.12; 0.21; 0.72; 2.39 and 2.50 cases per 1,000 person-years, respectively. Respiratory symptoms and urticaria were positively related with latex sensitization (OR = 8.0; 95 % CL 1.27-48.6), with common allergic respiratory symptoms (OR = 4.19; 95 % CL 1.04-16.8) and with familial atopy (OR = 4.47; 95 % CL 1.1-17.9).

CONCLUSION

The incidence of latex sensitization and latex-related symptoms were very low but subjects with allergic symptoms related to common allergens are at higher risk. The use of non-latex gloves is suggested for them.

Occupational asthma: new deleterious agents at the workplace

This article summarizes the main new categories of occupational agents responsible for causing occupational asthma, with and without a latency period reported in the last 10 years. It also reports examples of occupational agents for which the fabrication processing or use have influenced the outcome of occupational asthma.

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.

Omalizumab for asthma: pharmacology and clinical profile

Asthma remains uncontrolled in a significant minority of patients despite apparently optimal therapy with conventional inhaled agents. Omalizumab, the first 'biological' therapy of asthma, has emerged as a potentially useful therapy of moderate-to-severe atopic asthma. When administered subcutaneously every 2-4 weeks, omalizumab binds to circulating IgE, preventing the interaction of IgE with high-affinity receptors. Placebo-controlled trials show that its use reduces exacerbation frequency, thereby allowing decreases in the dosage of inhaled or oral steroids, while improving health status (i.e., quality of life). This article reviews the pharmacological aspects of this medication, the clinical studies supporting its use and the recent safety concerns highlighted by the US FDA.

Latex-induced occupational asthma: time trend in incidence and relationship with hospital glove policies

BACKGROUND

Natural rubber latex (NRL) has become as a major cause of occupational asthma (OA) in workers using NRL gloves. Few population-based studies have assessed the impact of changes in the patterns of glove usage on the incidence of NRL-induced OA.

OBJECTIVE

To characterize the time trends in incident cases of NRL-induced OA in Belgium and examine whether incidence rates were related to the types of gloves used in hospitals.

METHODS

Incident cases of NRL-induced OA were identified through a retrospective review of all claims submitted to the Workers' Compensation Board up to December 2004. Based on the results of diagnostic procedures, the diagnosis of NRL-induced OA was categorized as definite, probable, unlikely, or indeterminate. The patterns of glove usage were characterized through a questionnaire survey of Belgian hospitals.

RESULTS

A total of 298 claims for NRL-induced OA were identified, including 127 subjects with definite OA and 68 with probable OA. Categorized by the year of asthma onset, the incident cases of definite and probable NRL-induced OA markedly decreased from 1999 onwards. The use of powdered NRL gloves fell from 80.9% in 1989 to 17.9% in 2004. Powdered NRL gloves were predominantly substituted with NRL-free gloves, especially in the case of non-sterile procedures.

CONCLUSION

These national compensation-based data confirm that a persistent decline in the incidence of NRL-induced OA has occurred since late 1990s. This downward trend has temporally been associated with a decreasing usage of powdered NRL, further supporting a beneficial role of changes in glove policies.

Exercise with latex sport bands represents a risk for latex allergic patients

Based on two clinical observations of adverse reactions during exercise with latex sport bands, we aimed to assess the possible risk for allergic patients posed by this equipment by investigating allergen content and IgE binding potential. Protein extracts of three different latex sport bands were characterized with sera of latex allergic patients. The IgE recognition profile of the allergic patients was identified by component resolved diagnosis and the allergen composition of the extracts was characterized by inhibition assays with the recombinant latex allergens Hev b 1, 3, 5, 6.02, and 8. The sera showed pronounced IgE binding to all three blotted extracts, however with diverse patterns. Inhibition assays revealed the presence of Hev b 1, 3, 5, and 8 in latex sport band extracts. The clinical relevance of contained allergens was demonstrated by strong skin reactions when testing with latex sport bands. From our results we conclude that latex sport bands contain clinically relevant allergens and may cause latex allergic individuals to experience allergic symptoms, potentially amplified by exercise-induced mechanisms. Even though latex is labeled on products, it is important that patients as well as athletic trainers and physical therapists recognize the risk of adverse reactions with these bands.

Double-blind, placebo-controlled study of sublingual immunotherapy in patients with latex-induced urticaria: a 12-month study

BACKGROUND

Natural rubber latex (NRL) allergy is a worldwide problem. Although prevention is sufficient to reduce sensitization, prolonged avoidance is needed to prevent resensitization or adverse reactions on re-exposure.

OBJECTIVES

This double-blind, placebo-controlled study was conducted to determine the efficacy of sublingual immunotherapy (SLIT) with latex.

METHODS

Forty patients with NRL allergy were enrolled. At diagnosis, 30 presented urticaria and 10 asthma. Patients were evaluated on their clinical history and an allergological assessment: skin prick test with latex extract, serum-specific IgE and provocation tests. Patients were subdivided by complaint (asthma or urticaria), and randomized to receive SLIT with latex extract (ALK-Abelló, Lainate, Milan, Italy) or placebo.

RESULTS

The evaluable population consisted of 35 patients, 18 treated with SLIT and 17 with placebo. The results show that 12 months of SLIT improved the symptoms score and reduced the medication score in all subjects. The subjective evaluation was corroborated by improved bronchial and glove provocation test results. The latex-specific IgE levels increased slightly in the SLIT group, and skin sensitization was reduced at the end of the trial in all the patients treated with SLIT. The immunotherapy was not complicated by any severe adverse reactions.

CONCLUSIONS

This is the first double-blind, placebo-controlled evaluation of the efficacy of SLIT with latex extract conducted in adult patients allergic to NRL. SLIT with latex can be proposed for subjects with latex allergy, especially those for whom complete avoidance of latex exposure may be very difficult or even impossible. More studies are needed to evaluate the efficacy of SLIT in the treatment of subjects with latex allergy who are sensitized to inhalant allergens.

Prevention of occupational asthma in Ontario

Occupational asthma continues to be one of the most common occupational lung diseases in industrialized areas. Primary and secondary preventive measures have been well described, but there are relatively few studies to support the effectiveness of such measures, although the benefits of tertiary measures such as early recognition and removal from further exposure to a causative sensitizing agent are well recognized. In Ontario, a combined approach of preventive measures has shown effectiveness in allergy and asthma from occupational exposure to natural rubber latex. In addition, a program to reduce exposure to diisocyanates and introduce medical surveillance was associated with earlier diagnosis and fewer cases in a compensation population. However there remain barriers to the early diagnosis of occupational asthma in Ontario, especially in workers of lower education and lower income. In addition, there is recognized need for further physician education to allow early suspicion and diagnosis of occupational asthma.

Self-reported allergy to latex gloves among health care workers in Jordan

The objective of this study is to determine the prevalence of natural rubber latex allergy and its associated factors among health care workers in Jordan based on a self-administered questionnaire. In this cross-sectional study, the data were obtained through a self-reported hand-delivered questionnaire that was distributed to 500 health care workers who use natural rubber latex gloves. A total of 420 (84%) health care workers responded by filling the questionnaire. Of the total number of 420 health care workers who filled the questionnaire, 57 (13.6%) reported allergy to latex gloves. The prevalence of allergy to latex gloves was significantly higher for those who had allergy to some foodstuffs (especially avocado, kiwifruits and chestnuts) or with history of eczema and hay fever. However, allergy to latex gloves was independent of gender, age, job, family history, type of gloves, hours of use/day and number of years of use. It is concluded that a high rate of allergy to latex gloves was reported among health care workers in Jordan.

Prevention of latex sensitization in guinea pigs by a bacterial and viral filter used in anaesthesia

BACKGROUND

Preventing anaphylactic reactions as a result of natural rubber latex (NRL) proteins is an important concern in anaesthesia. The clinical relevance of a bacterial/viral filter (Pall BB25) in preventing sensitization to NRL by inhalation was tested in guinea pigs.

METHODS

Guinea pigs (n=8-10 in each group) were exposed to aerosolized NRL-contaminated cornstarch powder or to NRL in saline for 1 h every day for 2 weeks. The experiments were repeated with a Pall BB25 filter placed over the aerosol system. Control groups were exposed to non-contaminated cornstarch or to saline alone. Three weeks after the last exposure, specific bronchial challenge was performed and thromboxane (Tx) B2 levels in bronchoalveolar lavage fluid were measured.

RESULTS

After bronchial challenge, the animals exposed to NRL or NRL-contaminated cornstarch with the BB25 filter in place showed a level of bronchoconstriction (i.e. the variation of pulmonary insufflation pressure) not different from controls. Conversely, those exposed to NRL or NRL-contaminated cornstarch without the filter showed a higher level of bronchoconstriction (respectively, P<0.02 and P<0.001) than control. Elevated TxB2 levels were found in the lungs of the guinea pigs, which inhaled NRL or NRL-contaminated cornstarch in the absence of a filter. Animals treated with the filter showed comparable TxB2 levels with those of control.

CONCLUSION

The Pall BB25 filter efficiently protected the guinea pigs from sensitization to NRL. This filter can be used as a complementary measure for avoidance of NRL contact during surgical procedures particularly if the mechanical ventilator apparatus contain NRL devices.

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.

Failure rates in nonlatex surgical gloves

BACKGROUND

The purpose of this study was to compare the frequency of glove defects for nonlatex surgical gloves while surgeons performed routine surgery and to evaluate surgeons' satisfaction with nonlatex sterile gloves.

METHODS

Two brands of latex gloves and 6 brands of nonlatex gloves were tested. Gloves were collected at the end of each surgical procedure and tested for visual defects and barrier integrity using an automated calibrated water test machine consistent with FDA's recommended standards. A total of 6386 gloves used by 101 surgeons and 164 residents representing 15 surgical services were included in the analysis.

RESULTS

Higher after-use defect rates occurred in nonlatex surgical gloves than in latex gloves. Higher times of use were related to higher defect rates for some surgical specialties, and both surgeons and residents were less satisfied with nonlatex surgical gloves.

CONCLUSION

Intact latex and nonlatex surgical gloves provide adequate barrier protection. Nonlatex surgical gloves have higher failure rates and lower user satisfaction than latex gloves do. Both nonlatex and latex gloves should be changed after 2 to 3 hours of use because the barrier of either type of glove becomes compromised with extended use.

Effect of reduced exposure on natural rubber latex sensitization in health care workers

BACKGROUND

Knowledge about the long-term course of allergy or sensitization to natural rubber latex (NRL) is insufficient.

OBJECTIVE

To investigate the long-term effect of preventive measures on sensitization variables in health care workers who had been diagnosed as having NRL allergy (NRLA) or NRL sensitization (NRLS) without clinical symptoms.

METHODS

Repeated follow-up investigations, skin prick tests, and NRL specific IgE serum antibodies were performed in 88 health care workers-33 with NRLA and 55 with NRLS. All workers had been instructed to avoid NRL exposure. At the workplace, powder-free NRL gloves for all other employees were gradually introduced. Re-evaluations were done at 14 +/- 3.7 (N = 86) and 38 +/- 4.0 (N = 78) months after the first examination.

RESULTS

At the last follow-up, a loss of skin prick test reactivity to NRL was observed in 1 of 29 subjects with NRLA (3.4%) and 16 of 35 with NRLS (45.7%) with previous skin test reactions (P < .001). Among those subjects who demonstrated a kU/L level (CAP class) equal to or greater than class I to NRL at the initial examination, NRL-specific IgE was absent at the last follow-up in 8 (32.0%) of 25 subjects with NRLA and 14 (38.9%) of 36 with NRLS. At the final examination, we could no longer demonstrate sensitization to NRL by any method in 24 (27.3%) of 88 health care workers. Complete loss of NRL sensitization was less frequent in subjects with NRLA than in those with NRLS (1 of 33 or 3.0% vs 23 of 55 or 41.8%; P < .001).

CONCLUSIONS

Implementation of simple preventive measures lowers markers of sensitization to NRL quickly in many health care workers with NRLA or NRLS.

Type I latex allergy in health care workers with latex-induced contact urticaria syndrome: a follow-up study

BACKGROUND

Latex allergy is an important occupational health issue among health care workers (HCWs). Secondary prevention in sensitized/allergic individuals involves avoiding exposure to NRL products.

AIMS OF THE STUDY

The aim of this follow-up study is to determine the long-term health consequences in HCWs with type I latex allergy with latex-related contact urticaria syndrome, of providing appropriate information and practical avoidance education.

METHODS

Seventeen HCWs with latex-induced contact urticaria syndrome, as ascertained by the glove use test, were investigated. Initial and follow-up visits included: a detailed questionnaire, skin prick test (SPT) with glove eluates and with commercial latex extract, SPT with common inhalant and food extracts, serum specific immunoglobulin (Ig)E to latex and some foods and the glove use test.

RESULTS

On re-examination, 11 (64.7%) subjects showed positive SPTs to extemporaneous extract and 10 (58.8%) patients showed a positive SPT to commercial extract. Of the nine patients with detectable levels of serum latex specific IgE at first evaluation, four (44.4%) became negative and four were assigned to at least one class lower. Only one (11.1%) employee had higher radioallergosorbent test values than those at the latex allergy diagnosis. At follow-up, the 17 individuals had positive latex challenge results, although the duration of exposure causing a reaction increased.

CONCLUSION

Our study shows that preventive measures are sufficient to induce a reduction of sensitization. Continued avoidance is needed to prevent re-sensitization or adverse reactions on re-exposure.

Inhaled cornstarch glove powder increases latex-induced airway hyper-sensitivity in guinea-pigs

BACKGROUND

Breathing is one of the most important modes of sensitization to natural rubber latex (NRL) for health-care workers, a group most at risk. Cornstarch powder (CSp) from medical powdered NRL gloves is known to be an allergen carrier, and sensitization to NRL can occur by inhaling airborne particles from such gloves.

OBJECTIVE

The aim of this study was to demonstrate, using an experimental model, which CSp may act as an adjuvant in NRL-induced airway hyper-responsiveness.

METHODS

Guinea-pigs were exposed to aerosolized NRL-contaminated CSp or to NRL in saline solution for 1 h every day for 2 weeks. The control groups were exposed either to CSp or to saline alone. An additional group of guinea-pigs was exposed to aerosolized ovalbumin (OVA) in saline. Three weeks after the last exposure, specific bronchial challenges were performed. In addition, Specific IgG and IgG1 in sera and thromboxane (Tx) B(2) levels in bronchoalveolar lavage fluid (BALF) were measured.

RESULTS

The NRL challenge caused significant bronchospasm in the animals that had been exposed to NRL compared with those in the control groups (P<0.02). Guinea-pigs exposed to OVA also demonstrated a significant bronchospasm after OVA challenge (P<0.001). The guinea-pigs that had inhaled NRL-contaminated CSp had a significantly higher bronchoconstriction level than those that had inhaled NRL alone (P<0.02). Specific IgG and IgG1 were undetectable in sera from all groups, whereas significant amounts of TxB(2) (P<0.001) were found in the lungs of the guinea-pigs exposed to NRL or OVA.

CONCLUSION

Inhaling CSp increases the airway response to NRL. The fact that specific IgG and IgG1 were not detected might be the result of an immune response limited to the airways. This finding is supported by a significant increase of TxB(2) level in the BALF of sensitized guinea-pigs.

Etiopathogenesis and Management of Perennial Allergic Rhinitis

Perennial allergic rhinitis is an inflammatory disorder characterized by symptoms of nasal congestion, rhinorrhea, sneezing, and itching. The prevalence of allergic rhinitis is quite common and affects 20% or more of various populations. Some patients with allergic rhinitis are symptomatic only during the pollen season, while many others are allergic to multiple allergens including indoor allergens such as house dust mites, animal dander, cockroaches, and fungi, which lead to perennial symptoms. Immunoglobulin (Ig)-E is the proximate cause of perennial allergic rhinitis. Circulating IgE antibodies bind to the high affinity IgE receptor on mast cells and basophils. IgE antibodies, bound to the receptors crosslinked by allergen, initiate the secretion of inflammatory mediators including histamine, leukotrienes, and cytokines. These mediators can induce both acute and chronic changes that result in symptoms of allergy. Many therapies are approved for the treatment of allergic rhinitis including intranasal corticosteroids, antihistamines with or without decongestants, and nasal cromolyn sodium (sodium cromoglicate). Allergen avoidance is the mainstay of therapy for many patients but is not always practical. For those patients who have not responded to appropriate medications, allergen specific immunotherapy may also be effective.A number of studies with omalizumab have shown that it is effective in the treatment of seasonal allergic rhinitis induced by pollen such as ragweed and birch pollen. Omalizumab is a molecularly cloned humanized monoclonal antibody inhibiting human IgE. It binds specifically to the region of the IgE molecule that binds to the IgE receptor on the mast cell or basophils. Because omalizumab cannot bind IgE molecules that are already bound to the surface receptors on mast cells and basophils, it does not stimulate secretion of mediators from these cells. Omalizumab does not appear to stimulate an immune response against itself. It rapidly reduces free serum IgE levels by over 95% when administered at therapeutic doses and also results in the reduction of IgE receptors on mast cells and basophils. The combined effects of reduction of both free IgE in serum and the receptor density on the mast cells or basophils results in decreased allergen-stimulated mediator release. Preliminary studies in the treatment of perennial allergic rhinitis supports omalizumab's efficacy and safety. The compound has been well tolerated. Aside from urticarial reactions, adverse effects appear to be minimal. Omalizumab is the first of several new immune-based specifically targeted molecules that may prove to be extremely valuable in the treatment of perennial allergic rhinitis, as it is often unresponsive to traditional therapies.

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.

Minimizing latex exposure and allergy. How to avoid or reduce sensitization in the healthcare setting

Healthcare professionals with long-term exposure to natural rubber latex products and patients who undergo multiple operations are at high risk for latex allergy. The clinical spectrum of this allergy ranges from self-limited contact urticaria to involvement of multiple organ systems in anaphylaxis. In this article, Dr Muller explores the roots of the latex allergy epidemic and offers insight into the manufacturing process of latex gloves. She also presents a clinical approach to prevent or ameliorate sensitization and manage allergic symptoms.

Have health conditions associated with latex increased since the issuance of universal precautions?

OBJECTIVES

This study explored whether the prevalence of latex-related health conditions has increased among individuals employed in medical occupations relative to those employed in nonmedical occupations since the issuance of universal precautions in 1987.

METHODS

Data derived from the 1983 to 1994 versions of the National Health Interview Survey were used to obtain odds ratios comparing prevalence rates of latex-related symptoms over time.

RESULTS

No statistical evidence was found that the universal precautions resulted in increased prevalence rates of latex-related health conditions among medical workers relative to those employed in nonmedical occupations.

CONCLUSIONS

Increased use of latex gloves among health care personnel subsequent to the implementation of universal precautions appears to have had no effect on latex allergic reactions experienced by these workers.

A laboratory-based study to assess the performance of surgical gloves

The inherent tear resistance and elasticity of latex and the touch sensitivity it provides has made it the traditional material of choice for surgical gloves, protecting both health care workers and patients from the transmission of bloodborne infections. Although increased incidence of latex allergy has led to increased use of nonlatex surgical gloves, the effectiveness of these gloves as a barrier to infection has not been examined thoroughly. This laboratory-based study compared the performance of latex and nonlatex surgical gloves in a simulated stress protocol. The propensity of surgical gloves to fail was dependent on glove material, manufacturer, and stress. Nonlatex neoprene and nitrile gloves were comparable to latex and can provide a good alternative to latex for allergic patients and health care workers. In this study, isoprene was found to be inferior to latex and other nonlatex materials. The presence or absence of glove powder had no significant influence on the probability of glove failure.

Workers' compensation claims related to natural rubber latex gloves among Oregon healthcare employees from 1987-1998

BACKGROUND

Occupational reaction to natural rubber latex (NRL) glove use by healthcare employees has been an area of increasing concern. Unfortunately, there is little data demonstrating the prevalence and severity of actual reactivity to NRL.

METHOD

Occupational reaction to NRL was estimated using workers' compensation claims filed by healthcare employees in Oregon for the period of 1987-1998. For the first ten years, these claims were estimated by source and conditions consistent with NRL glove reactions, while in the last two years a specific code developed in 1997 for NRL glove reactions was also employed.

RESULTS

The claim rate was on average 0.58 per 10,000 healthcare workers annually, which constituted 0.29% of all workers' compensation claims. The most common condition experienced was dermatitis (80%) and most common body part affected was the hands (55.4%). The majority of claimants, 45 (69.2%), reported taking less than a month off work, suggesting most reactions were minor in nature, although one fatality was reported. The average NRL claim cost was $8,309.48. Overall the average cost per insured healthcare worker was approximately $0.50 per year. The occupational groups with the highest number of claims were nurses (30.8% of claimants) and nursing aides and orderlies (24.6% of claimants).

CONCLUSIONS

In comparison with other workers' compensation claims filed by healthcare workers during this period, 0.25% of the total was potentially related to NRL gloves. The rare incidence of respiratory and ocular claims is inconsistent with the hypothesis that asthmatic or conjunctival reactions to NRL gloves are common.

Epidemiology of latex sensitization and allergies in health care workers

Although it is often claimed that health care workers are at increased risk of latex sensitization and type I allergies, there has been no systematic analysis of the epidemiologic studies that are relevant to this conclusion. A systematic analysis of the epidemiologic literature found that, in the past 14 years, there have been 48 epidemiologic studies of type I latex allergy among health care workers. Of these, 2 cohort studies estimated the incidence of latex sensitization by skin prick testing at between 1% and 2.5% per year. Neither compared the risk to that in the general population. The prevalence of sensitization in health care workers varied between 0% and 30%, yet this large variation was unexplained. Increased risk of sensitization was not clearly associated with the duration of work in health care, the time spent wearing latex gloves, the frequency of exposure, the specific job categories, the use of powdered versus nonpowdered latex gloves, the use of latex versus nonlatex gloves, or any measurements of ambient exposure to latex proteins. The epidemiologic studies do not support a conclusion that health care workers are at clearly increased risk of latex sensitization or type I allergies compared to other occupations in the United States. The role of latex gloves in causing latex sensitization and type I allergic symptoms remains poorly defined because of the inconsistent results across studies. Future epidemiologic studies are needed that include measured exposures to latex antigens, that compare health care workers to appropriate referent groups, and that address confounding by atopy, age, sex, and race.

Management of occupational allergy to natural rubber latex in a medical center: the importance of quantitative latex allergen measurement and objective follow-up

When our employees began coming to the Occupational Health Service, Dermatology, and Allergy Clinics with symptoms of allergy to rubber gloves 12 years ago, the Mayo Clinic initiated 3 responses. (1) The Allergic Disease Research Laboratory adapted well-established technology to measure both the IgE antibody specific to natural rubber allergens, and by use of this IgE antibody, the allergens in rubber products and in the air of the workplace. (2) The Division of Allergic Diseases and Internal Medicine reviewed the prevalence and severity of the problem. (3) The Clinical Practice Committee appointed a multidisciplinary task force to implement measures to reduce exposure. The 3 sections of this article describe the Mayo Clinic's experience of successful control of this occupational health problem. Use of only gloves with low or undetectable allergen content greatly reduced the concentration of allergen in the work site, reduced the number of new cases of occupational allergy to rubber, and allowed individuals with latex allergy to work at their usual jobs.

Latex allergy: the perspective from the surgical suite

Latex allergy in the perioperative setting presents unique challenges to the health care system. Specific needs of the latex-sensitive patient are paramount, but consideration must also include the impact on health care workers vis-a-vis latex sensitization, environmental allergen control, and barrier protection against blood-borne pathogens. It has been well documented that the greatest source of latex aeroallergen in the surgical setting is latex gloves (both sterile and nonsterile). Levels of latex aeroallergen correlate strongly with use of high-allergen and powdered gloves, total number of gloves used, and the hours of activity in a given environment. A significant reduction in aeroallergen (>10-fold) can be achieved by switching to low-allergen gloves. Ready availability of and encouragement to use nonlatex alternatives when appropriate can further reduce exposure to latex allergens. Since 1998, the Food and Drug Administration has required all medical devices (or their packaging) that contain natural rubber latex to be so labeled. In addition, industry has responded with a host of latex-free products for use in patient care. This has helped eliminate a great deal of confusion about which products are safe for use with latex-sensitive individuals. However, despite significant efforts to educate the public and the health care industry regarding latex allergies, considerable misinformation persists. Provision of a completely latex-free environment in most surgical suites may be unrealistic, but every effort should be made to minimize the unnecessary exposure of patients and health care workers to latex allergens in this high-risk arena.

Particulate masks and non-powdered gloves reduce latex allergen inhaled by healthcare workers

BACKGROUND

Although allergy to latex is a well-characterized phenomenon, some hospitals continue to provide staff with powdered latex gloves as an option to low- or non-powdered gloves.

OBJECTIVE

We aimed to measure the extent to which inhalation of latex particles could be reduced by the use of protective masks or by replacing powdered latex gloves with non-powdered latex gloves.

METHODS

Twenty healthcare workers in a hospital setting wore nasal air samplers (NAS) and Institute of Occupational Medicine (IOM) samplers for four 20-min periods. Subjects wore powdered gloves, non-powdered gloves and no gloves during three sampling periods, and in the fourth, subjects applied an aerosol barrier face-mask or a particulate face-mask (N95) while wearing powdered gloves. All samples were stained for particles bearing Hev b 5 allergen by the Halogen assay.

RESULTS

All subjects inhaled Hev b 5 bearing particles in all sampling periods. IOM samplers collected particles at 70% of the rate of NAS. The number of particles inhaled while wearing powdered gloves was 23.8-fold higher than when not wearing gloves and 9.7-fold higher than when wearing non-powdered latex gloves (P < 0.0001). Wearing an aerosol barrier mask did not significantly reduce the number of particles inhaled (P = 0.108), while use of particulate masks significantly reduced the number of particles inhaled by 17.4-fold (P = 0.003).

CONCLUSIONS

Use of non-powdered gloves is the most effective method of reducing occupational aeroallergen exposure to latex arising from gloves. However, secondary protection using particulate masks is a valid alternative, and may be helpful for preventing respiratory sensitization.

Allergic and latex-specific sensitization: route, frequency, and amount of exposure that are required to initiate IgE production

Quantitative data that documents human exposure-response relationships for IgE sensitization to allergens are limited. Although seemingly straightforward, documentation of exposure-response relationships can be difficult. Issues that are related to study design, allergen standardization, exposure assessment, and evaluation for sensitization can impact greatly on study results. Despite these issues, exposure-response relationships for sensitization to protein allergens have been documented in several occupational groups, which include enzyme-detergent workers, bakers, and laboratory animal workers. In general, atopy acts as an effect modifier in these settings, steepening the exposure-response relationship. Several studies suggest that the greatest risk for sensitization is within the first several years of exposure. For 1 allergen, the protease subtilisin, a short-term exposure limit of 60 ng/m(3) has been recommended by the American Council of Governmental Industrial Hygienists. With regard to natural rubber latex, exposure-related factors such as number of operations have been shown to be risk factors for sensitization of children with spina bifida. By contrast, fewer studies show exposure-response relationships for IgE sensitization of health care workers to natural rubber latex, and the area remains controversial. However, a recent cohort study that evaluated incident sensitization in dental hygiene students suggests strongly that, with sufficient exposure, employment in health care can lead to an increased risk of IgE sensitization to natural rubber latex.

Occupational asthma and rhinoconjunctivitis induced by natural rubber latex exposure

A number of reports indicate that occupational exposure to natural rubber latex (NRL) in health care workers can elicit symptoms of rhinoconjunctivitis with or without asthma in selected individuals who are sensitized. The prevalence or risk of NRL-induced asthma in relation to rhinoconjunctivitis is small in comparison with other forms of occupational allergic respiratory disease. The lower risk of NRL-induced asthma appears to be related to poor penetration of the allergen into the lower respiratory tract because of the relatively large particle size of allergen-bearing cornstarch particles. Because of a lack of large prospective studies, little is know about the incidence and natural history of latex-induced respiratory disease. Because of heightened awareness of NRL allergy and changing patterns in glove manufacturing and glove use, it is likely that the occurrence of NRL-induced occupational respiratory disease will decline and its natural history will change. Nevertheless, because large number of individuals are exposed to NRL in various occupations, the incidence, prevalence, and natural history of NRL allergy merit further monitoring.

IgE-mediated natural rubber latex allergy: practical considerations for health care workers

OBJECTIVE

To focus on some specific topics of major significance for health care workers confronted with natural rubber latex (NRL) allergy: 1) sensitization and routes of exposure; 2) threshold allergen exposure levels; 3) evaluation of occupational NRL allergy; 4) prevention of sensitization and allergic reactions to NRL-containing devices; 5) selecting the right alternative; and 6) regulatory responses to NRL allergy issues.

DATA SOURCES

English and French language papers identified through a MEDLINE search and bibliographies of the identified papers and the National Institute for Occupational Safety and Health and Food and Drug Administration web sites.

RESULTS

1) The threshold levels of NRL exposure needed for sensitization and the precise way in which it comes about remain to be elucidated, but cutaneous, percutaneous, mucosal, and parenteral exposure can all give rise to symptoms. 2) Strengths and weaknesses of the questionnaire and currently available diagnostic techniques for NRL allergy are emphasized. 3) Prevention strategies should focus on dipped materials and stress upon the possibility of passive and active transmission of NRL aeroallergen. 4) Generally, vinyl gloves are an appropriate alternative for NRL gloves; however, when barrier integrity is a concern, nitrile gloves provide protection that is comparable with NRL. 5) Several government bodies, standards organizations, and regulatory agencies have issued regulations concerning the control and labeling of protein and allergen levels in NRL products.

CONCLUSION

Accurate diagnosis and management of NRL allergy is essential because of the potential for severe hypersensitivity reactions. Major developments have been made in characterizing and cloning NRL allergens, and future development in this area may lead to better diagnostic tools and possible therapeutic agents for immunotherapy. However, at present, avoidance remains the only effective approach. We hope that additional well performed prospective incidence studies will bring more accurate data concerning sensitization doses and provide the valuable information to improve prevention strategies.

Scrubbing for cutaneous procedures can be hazardous

Office-based minor cutaneous surgery is a service provided by many medical practitioners. In New South Wales, Australia, it is a legal requirement for practitioners to surgically scrub before donning sterile gloves for all forms of invasive surgery, including minor cutaneous procedures. Frequent scrubbing causes altered skin barrier function, irritant dermatitis and a potential risk of latex sensitization. These adverse effects are associated with significant morbidity and cost. Better tolerated alternatives, including alcohol-based hand rubs, should be considered in preference to traditional surgical scrubs in order to reduce these occupational risks for minor proceduralists. Well-controlled, prospective studies should explore what extent of hand washing is necessary for donning sterile gloves for minor cutaneous surgery.

Regulatory initiatives for natural latex allergy: US perspectives

The US Food and Drug Administration (FDA) has regulatory authority over foods, human drugs, cosmetics, medical devices, radiological products, biologics, and veterinary products. Among these products, FDA believes that the use of medical devices, including medical gloves, condoms, catheters, and breathing bags, represents the greatest source of natural latex proteins to exposed individuals. A medical device is defined in the Federal Food Drug and Cosmetic Act (FFDCA) as an instrument, apparatus, implement, machine, etc., that is intended for use in the diagnosis or treatment of disease or is intended to affect the structure or any function of the body of a human or other animal, and that does not achieve any of its principal intended purposes through chemical action in the body. This article provides some brief, general background about FDA's medical device regulatory process and then addresses the issue of natural latex allergy. Finally we discuss the steps the Agency has taken to evaluate the magnitude and nature of the problem, and FDA's efforts to assist manufacturers, health professionals, and others in minimizing exposure and sensitization to natural latex proteins in medical devices.

Specific monoclonal antibodies and human immunoglobulin E show that Hev b 5 is an abundant allergen in high protein powdered latex gloves

BACKGROUND

Hev b 5 is a major latex allergen recognized predominantly by latex-allergic health care workers (HCWs). Recombinant Hev b 5 (rHev b 5) was previously expressed as a fusion protein with maltose binding protein (MBP), itself an immunogenic molecule; therefore non-fusion rHev b 5 is desirable. Moreover, standardized immunological assays for the detection of Hev b 5 are currently lacking and may have important implications for both allergen avoidance and diagnosis in latex allergy.

OBJECTIVES

To generate and use Hev b 5-specific mAbs to determine the relative abundance of Hev b 5 in different latex extracts, correlating this with the IgE reactivity of latex-allergic HCWs and to produce non-fusion rHev b 5.

METHODS

For the production of mAbs, mice were immunized with rHev b 5/MBP fusion protein and mAbs selected with rHev b 5/MBP but not MBP reactivity. The mAb reactivity was compared with polyclonal IgE from latex-allergic HCWs using direct and inhibition ELISA and immunoblot assays. Recombinant Hev b 5 was expressed and purified in the pPROEX-HTa bacterial expression system.

RESULTS

Four Hev b 5-specific mAbs were produced. Immunoblotting and ELISA using the mAbs indicate abundant Hev b 5 in high protein powdered latex glove extracts as compared with crude latex sap extracts. High quality surgical gloves with no detectable protein have no detectable Hev b 5. Inhibition ELISAs using serum IgE from latex-allergic HCWs and Hev b 5-specific mAbs gave strong correlation. Non-fusion recombinant Hev b 5 was successfully expressed and purified, showing reactivity with both the Hev b 5-specific mAbs and serum IgE of latex-allergic HCWs.

CONCLUSION

Hev b 5-specific mAbs and human IgE from latex-allergic HCWs demonstrate the greater content of Hev b 5 in high protein powdered glove extracts. This may explain the observed higher frequency of sensitization to this allergen in HCWs.

Inhaled latex allergen (Hev b 1)

BACKGROUND

IgE-mediated responses to natural rubber latex allergens have become a major health problem among recognized risk groups.

OBJECTIVE

The purpose of this investigation was to measure the amounts of Hevea brasiliensis latex allergen (Hev b 1) inhaled and deposited on surfaces when latex or vinyl gloves were worn and compare the results with the conventional measures (breathing zone samplers) of occupational exposure.

METHODS

Hev b 1 exposure was measured by nasal sampling and breathing zone sampling. Latex allergen exposure was generated by having each subject don a pair of powdered latex examination gloves and continuing his or her normal daily activity for 30 minutes. By means of adhesive tape, surface dust samples were collected from the surfaces of gloves, the subject's hands, and work areas. Sampling was performed with subjects wearing no gloves, subjects wearing powdered vinyl gloves, subjects wearing powdered latex gloves, and nearby colleagues wearing latex gloves. All samples were assayed through use of the HALOgen assay (Inhalix, Sydney, Australia) with a Hev b 1-specific mAb. Particles transporting latex allergen were identified by a surrounding immunostain halo, and these were quantified and reported as total numbers of particles inhaled, airborne, or found on surface areas evaluated.

RESULTS

Study subjects inhaled 26 times more allergen when powdered latex gloves were worn than under the "no glove" and powdered vinyl glove conditions. During the same period, Hev b 1 particle levels measured in the ambient air through use of the breathing zone sampler increased by 24-fold. The median numbers of particles carrying Hev b 1 allergen per square centimeter on the surface of the hands after the wearing of latex and vinyl gloves were 1964 and 5, respectively. Latex allergen was physically associated both with cornstarch granules and with larger dust particles having a darker, more irregular appearance.

CONCLUSION

In a laboratory where gloves are worn for protection, the use of latex gloves resulted in a 26-fold increase in inhaled latex allergen over background levels measured while vinyl gloves were worn as controls. Low levels of latex exposure also occurred when vinyl gloves or no gloves were worn; the reasons for this are under investigation.

Performance of latex and nonlatex medical examination gloves during simulated use

BACKGROUND

In response to the rise in latex allergies, gloves made from a variety of nonlatex materials have been introduced into the health care environment. To date, at least 1 study, by Rego and Roley (1999), has reported that both latex and nitrile medical examination gloves provide comparable barrier protective qualities. The purpose of our study was to determine the effects of glove stress, type of material (vinyl, nitrile, copolymer, latex), and manufacturer on the barrier effectiveness of medical examination gloves.

METHOD

A total of 5510 medical examination gloves (1464 nitrile, 1052 latex, 1006 copolymer, and 1988 vinyl) were divided into 2 groups: stressed and unstressed. Unstressed gloves were visually inspected and water-tested according to the Food and Drug Administration water-testing standards. Stressed gloves were manipulated according to a designated stress protocol, visually inspected, and then subjected to the same Food and Drug Administration water-testing standards.

RESULTS

Our limited sample size demonstrated that nitrile gloves had the lowest failure rate (1.3%), followed by latex (2.2%); vinyl and copolymer gloves had the highest failure rate (both 8.2%). With use of a logistic regression analysis adjusting for manufacturer and stress, latex examination gloves were found to be 3 times more likely to fail than nitrile gloves (odds ratio, 3.2; 95% CI, 1.37-7.50). Nitrile gloves were also found to fail significantly less often than vinyl or copolymer gloves (odds ratio, 12.60; 95% CI, 5.80-27.40).

CONCLUSIONS

Nitrile examination gloves are a suitable alternative to latex, whereas vinyl and copolymer examination gloves were found to be less effective barriers. Further research is indicated to determine whether nitrile gloves can provide effective barrier qualities during clinical use versus laboratory simulations.

IGE-mediated natural rubber latex allergy: an update

In the past 2 decades, IgE-mediated NRL allergy has become a well-defined condition with recognised risk groups, established diagnostic tools, and adequate prevention strategies (1-3). Furthermore, molecular biology and biochemical techniques have significantly improved our knowledge of the proteins responsible to cause the disease. Clinical manifestations will not be addressed in this review, nor will broad preventive strategies be proposed; these have been discussed elsewhere (4, 5). After a brief introduction this review will focus on specific issues: (1) How do we estimate the prevalence of NRL allergy and who is at risk for clinical sensitisation? (2) What specific allergens cause NRL allergy? How does sensitisation for these allergens occur? Are all patients sensitised for the same allergens? Threshold allergen exposure levels. (4) What is the latex-fruit syndrome? What is the clinical relevance of a positive plant food specific IgE quantification in patients with NRL allergy? (5) How do we diagnose NRL allergy? What are the strengths and weaknesses of currently available diagnostic tools? (7) How do we manage NRL allergy? What is the role of medication and immunotherapy in the treatment of NRL allergy? How do we select an appropriate non-NRL alternative for NRL gloves? Which regulatory provisions have been implemented?

Latex allergy: past and present

Although latex products have been in use for over a century, allergic responses to latex proteins have only been recognized as a serious health problem for the past 15 years. Latex allergy particularly affects two groups, health care workers (HCW) and children with spina bifida (SB). This manuscript provides a brief history of latex allergy, and a review of the following: the manufacturing process for dipped latex products, the 11 latex allergens that have been characterized and received allergen designations by the International Union of Immunological Societies, the methods used in exposure assessment, the epidemiology and clinical management of latex allergy, and the use of animal models in investigating mechanisms underlying latex allergy.

Occupational asthma caused by natural rubber latex: outcome according to cessation or reduction of exposure

BACKGROUND

The long-term effects of reducing exposure to latex in subjects with latex-induced asthma remain unknown.

OBJECTIVE

The purpose of this study was to compare the health and socioeconomic outcomes of subjects with latex-induced asthma before and after reduction or cessation of exposure to latex.

METHODS

Thirty-six subjects with latex-induced asthma as ascertained by specific inhalation challenges were investigated after a median follow-up of 56 months (range, 12 to 92 months). Initial and follow-up visits included use of a detailed questionnaire and measurement of the concentration of histamine causing a 20% fall in FEV(1) (PC(20)). At follow-up, information on employment, financial status, and quality of life was collected.

RESULTS

At follow-up, 16 subjects were no longer exposed to latex, whereas 20 subjects had reduced exposure. In the subjects who avoided exposure, asthma severity decreased from a median score of 8.5 to 3.5 (P =.001) and the median histamine PC(20) value increased from 0.4 mg/mL to 2.3 mg/mL (P =.002). In the subjects who reduced their exposure, asthma-severity score improved from 6.5 to 2.5 (P <.001) and PC(20) values rose from 0.5 mg/mL to 2.4 mg/mL (P <.001). Cessation of exposure to latex was associated with asthma-related work disability (69%) and loss of income (62%) more frequently than was reduction of exposure (35% and 30%, respectively).

CONCLUSION

Reduction of exposure to latex should be considered a reasonably safe alternative that is associated with fewer socioeconomic consequences than removal from exposure.