Occupational asthma in a latex doll manufacturing plant

Secondary prevention of latex allergy

PURPOSE OF REVIEW

The present review addresses the secondary prevention in healthcare worker, healthcare setting, and in patients outside the healthcare setting.

RECENT FINDINGS

There is sufficient knowledge of the broad aetiology of latex allergy for secondary preventive programmes to be widely adopted. Currently, avoidance of latex-containing surgical products is mandatory in the care of sensitized patients. They should also have a list of occult sources of natural rubber latex exposure and cross-reacting fruits. During all health-care procedures latex allergic patients should be treated in a 'latex-free' environment. Specific sublingual immunotherapy has been suggested as a suitable therapeutic option. It can be offered, in addition to symptomatic treatment, to selected patients, when avoidance measures are not feasible or effective. The use of omalizumab could also be extended as an adjunct to latex immunotherapy.

SUMMARY

Despite of the progress made in the secondary prevention of latex allergy, the disease still continues to be a global health problem.

Update on latex allergy: New insights into an old problem

Despite the efforts made to mitigate the consequences of this disease, natural rubber latex allergy (NRLA) continues to be a global health problem and is still considered one of the main worries in the working environment in many countries throughout the world. Due to thousands of products containing latex, it is not surprising that the current statistics suggest that prevalence remains high among healthcare workers and susceptible patients. In developed countries, reduction in the prevalence of IgE-mediated allergy to latex proteins from gloves may lead to lax attention by health care personnel. On the other hand, this situation is different in developing countries where there is a lack of epidemiological data associated with a deficit in education and awareness of this issue. The aim of this review is to provide an update of the current knowledge and practical recommendations regarding NRLA by allergologists from different parts of the world with experience in this field.

Latex Allergy: Where Are We Now and How Did We Get There?

Latex allergy emerged as an epidemic of anaphylaxis, occupational asthma, and clinical dilemmas in the 1980s. A systematic recognition, investigation, discovery, epidemiology, and prevention strategy followed. International attention and collaborations of investigators, government agencies, manufacturing, and health policy resulted in near elimination of a global epidemic. This article summarizes nearly 4 decades of work in control of this epidemic and focuses attention on future problems that still require resolution.

Occupational rhinitis and occupational asthma: Association or progression?

BACKGROUND

Occupational asthma is the most frequently reported occupational respiratory disease in registries, and is often co-diagnosed with occupational rhinitis. We undertook a systematic review of the English-language epidemiologic literature linking these two conditions, with emphasis on progression from occupational rhinitis to occupational asthma.

METHODS

PubMed and Embase were queried in a series of structured searches designed to identify studies comparing occupational asthma and occupational rhinitis incidence or prevalence in occupationally exposed individuals.

RESULTS

The searches yielded a total of 109 unique citations, 15 of which yielded inferential data on the occupational rhinitis-asthma relationship. Nine of fifteen studies showed statistically significant associations between the occurrence of occupational rhinitis and occupational asthma among individual workers.

CONCLUSIONS

Limited data support the notion that occupational rhinitis precedes the development of occupational asthma, particularly when high-molecular-weight (HMW) agents are involved. The relationship between the two conditions could not be evaluated in many relevant studies due to a lack of cross-tabulation of individual cases.

Latex allergy

Allergy to natural rubber latex is an important clinical condition that occurred after the institution of universal precautions to protect healthcare workers. A rapid increase and production of both examination and surgical gloves resulted in an epidemic of allergy to latex protein. Healthcare workers in both the medical and dental environments, as well as specific groups of individuals including those with spina bifida, myelodysplasia, and food allergies (banana, kiwi, avocado, and others), were at increased risk of sensitization. Clinical symptoms in the latex allergic individual ranged from type I hypersensitivity reaction including rhinoconjunctivitis, asthma, and systemic reaction to type IV hypersensitivity reaction, which occur from the chemicals added during the manufacturing process. Diagnosis of latex allergy is based on a clinical history that correlates the development of symptoms in relationship to exposure. In the United States there are no skin tests approved by the Food and Drug Administration. Therefore a combination of clinical judgment and serologic testing such as ImmunoCAP and Immulite is helpful. The primary treatment of latex allergy is avoidance of exposure to the latex protein.

Prevention of occupational asthma--practical implications for occupational physicians

BACKGROUND

Occupational factors have been estimated to contribute to approximately 10% of adult-onset asthma and occupational asthma (OA) is one of the most common occupational lung diseases in industrialized areas. Persistent asthma frequently occurs with significant socio-economic impacts.

METHODS

A literature search was performed using PubMed. The key term searched was occupational asthma combined with prevention.

RESULTS

Primary prevention has been effective for OA related to natural rubber latex, and may have reduced the incidence of diisocyanate-induced asthma. Medical health surveillance has been effective in settings such as the detergent enzyme industry, workers exposed to complex platinum salts and likely for diisocyanate workers in Ontario. Tertiary prevention is still required for workers with OA and can improve prognosis.

CONCLUSIONS

OA is potentially preventable. Sufficient studies have demonstrated the rationale and benefit of primary preventive strategies. Medical health surveillance programs combined with occupational hygiene measures and worker education have been associated with improved outcomes but further studies are needed to understand the optimum frequency and measures for such programs and to identify the separate contribution of the components. Until primary and secondary prevention is better understood and implemented, there will also remain a need for tertiary preventive measures.

Prevention of latex allergy among health care workers and in the general population: latex protein content in devices commonly used in hospitals and general practice

BACKGROUND

In this study the latex protein content in devices commonly used in hospitals and general practice were investigated. The main aim was to acquire information for preventing latex allergy in health care workers and in the general population.

METHODS

About 22 different types of medical devices and 23 devices commonly used in general practice were examined evaluating the total allergenic potency by a modified RAST-inhibition assay and quantitative determination of single allergens (Hev b1, Hev b5 and Hev b6.02) by using commercial ELISA kit.

RESULTS

A high level of inhibition was found in medical devices, such as elastic bandage (81.57%), tourniquet (74.09%), Foley urinary catheter (68.35%), Penrose drainage (67.25%) and taping (39.6%), and in common devices, such as rubber inner-sole (84.20%), toy balloon (78.62%), latex mattress (74.27%), household rubber gloves (49.10%), working gloves (38.25%), inflatable floating mattress (32.10%). Concentrations of latex extractable proteins and Hev b1, Hev b5 and Hev b6.02 antigens were high in some medical and general devices.

CONCLUSIONS

Latex exposure sources were found in hospitals and the home. These findings, though only preliminary and far from conclusive, could enable sensitized persons to avoid risky exposures and prevent allergic reactions. From the point of view of prevention, the time may come when every natural rubber object could be systematically labelled as "containing latex" together with the warning that "this item may cause allergic reactions in sensitized subjects."

Strategies for distinguishing asymptomatic latex sensitization from true occupational allergy or asthma

OBJECTIVE

To evaluate strategies for distinguishing those individuals with true occupational asthma caused by exposure to natural rubber latex from those individuals with allergic disease related to other allergens.

DATA SOURCES

Article published between January 1, 1981, and December 31, 2001, were identified via a MEDLINE search with the following keywords: latex, allergy, asthma, occupation asthma, and adverse reactions.

STUDY SELECTION

English-language reports concerning diagnostic methods in latex and other forms of occupational asthma.

RESULTS

Many methods have been evaluated for the diagnosis of latex allergy, including medical history, skin prick tests, in vitro tests, and various challenge tests. Skin prick tests with well characterized latex extracts are highly sensitive and specific predictors of latex-specific IgE antibodies; however, direct pulmonary challenge with latex allergen appears to be the only highly reliable method for diagnosis of latex-related occupational asthma.

CONCLUSIONS

It is difficult to optimally distinguish between occupational latex asthma and asymptomatic latex sensitization in a person with preexisting asthma using currently available techniques.

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.

Latex allergy

The prevalence of IgE mediated natural latex rubber allergy is estimated to be < 1% in the general population, < 17% in medical personnel and approximately 0% in children with spina bifida. We review the definition, diagnosis, prevention, and treatment of NLR allergy.

Quantified environmental challenge with absorbable dusting powder aerosol from natural rubber latex gloves

BACKGROUND

There are few data that link quantified natural rubber latex (NRL) absorbable dusting powder aerosol to biologic responses in NRL-sensitized subjects.

METHODS

We conducted a study on 30 health care workers with possible occupational asthma. All the subjects but 2 had a positive skin prick test result with NRL extract. Quantified environmental challenge (QEC) with powdered NRL gloves was performed in a 7-m(3) chamber. The patients would don and discard a pair of gloves every 3 minutes up to a maximum of 60 minutes. The concentrations of NRL aeroallergen were measured by a competitive IgE immunoassay. Ocular and respiratory symptoms and pulmonary function were monitored.

RESULTS

Twenty-six patients (87%) had rhinoconjunctivitis, 19 (63%) had an asthmatic response (responders), and 1 patient developed eosinophilic bronchitis on QEC. The asthmatic responses were of the early type in 15 patients, dual in 3, and isolated late in 1 patient. The duration of exposures sufficient to elicit asthmatic responses varied from 3 to 114 cumulative minutes. Time-weighted average NRL aeroallergen concentrations during QEC with responders ranged between 199 and 1107 ng/m(3). NRL concentrations measured at various time points during exposure were reproducible. Measured concentrations of NRL aeroallergen between responders (677 +/- 281 ng/m(3)) and nonresponders (611 +/- 351 ng/m(3)) were not statistically different. The cumulative inhaled NRL aeroallergen dose required for an asthmatic response ranged between 25 to 515 ng.

CONCLUSION

The total dose of latex aeroallergen eliciting an asthmatic response during QEC was mostly affected by the duration of exposure and varied widely from person to person.

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.

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.

[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.

Sensitisation to natural rubber latex: an epidemiological study of workers exposed during tapping and glove manufacture in Thailand

OBJECTIVES

To estimate the prevalence of sensitisation to natural rubber latex in latex tappers and latex glove factory workers, and to relate this to airborne exposure to latex.

METHODS

Five hundred workers employed in three latex glove factories, 314 tappers, and 144 college students (control group) were studied. The workers in the glove factories were classified into three exposure groups; high, moderate, and low. Personal exposures to natural rubber latex aeroallergens were measured by immunoassay. Symptom questionnaires and skin prick tests with latex allergens (Stallergènes 1:200 w/v) and other common environmental allergens were performed. The criterion for positivity was a wheal reaction at least 3 mm in diameter greater than that to a diluent control.

RESULTS

The geometric mean (GM) concentration of latex in air was 15.4 microg/m(3) for those employed in glove stripping, glove inspections, and packing of powdered gloves. The moderate exposure glove manufacturing group and the tappers had GM concentrations of 2.3 and 2.4 microg/m(3) respectively, compared with United Kingdom users of latex powdered gloves,who had GM concentrations of 0.5 microg/m(3). The prevalence of sensitisation to latex in the tappers and latex glove factory workers was 1.3% and 1.7% respectively. No positive cases were found among the college students. Workers who showed a positive skin prick test to latex were more likely to be atopic. Work related respiratory and dermatological symptoms were found in about 20% of each population studied, but were not related to the presence of positive latex prick tests.

CONCLUSIONS

This study suggests that in the Thai latex industries, latex sensitisation is rare despite high concentrations of airborne exposure and is less prevalent than in the healthcare sector in Europe where skin exposure is greater.

Latex allergy: review of recent advances

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

Identification of allergenic proteins in condoms by immunoenzymatic methods

BACKGROUND

A large increase of allergy to latex proteins has been observed lately probably as a result of a great use of latex-containing goods. At present these untoward reactions have led to consideration of this problem as a health and occupational hazard. It is therefore, necessary to identify the allergens contained in latex-manufactured products and to develop effective diagnostic tools to detect sensitized individuals.

OBJECTIVE

The objective of this study is to identify antigenic and allergenic components in latex condoms by using chemical, immunochemical, and immunoenzymatic methods.

METHODS

The protein content of extracts obtained from several brands of condoms was determined and characterized by using a modified Lowry method, a quantitative ELISA assay and SDS-PAGE. The allergenic behavior of these proteins was studied by IgE immunoblotting, EAST and ELISA techniques, using sera from subjects allergic to latex products, particularly to latex condoms.

RESULTS

Wide variations in the protein content (38 to 740 microg/g product) and composition were observed. The SDS-PAGE protein profiles showed components ranging from 7 to 94 kD of relative molecular weights; most of them were also detected in natural rubber latex. The most prominent bands were revealed in the 14 and 30 kD zones. A strong band of 69 kD in the SDS-PAGE profiles would correspond to a neoantigen, since it was not observed in natural latex. The immunoblotting analysis employing sera from 5 patients allergic to latex condoms showed the presence of 4 components with IgE binding capacity (14, 30, 69, and 94 kD). The EAST and ELISA methods showed the presence of allergens in all the condom brands studied.

CONCLUSIONS

The presence of allergenic proteins in several condom brands was demonstrated by different immunoenzymatic methods.

The occupational hazards of emergency physicians

Emergency physicians are exposed to a variety of occupational hazards. Among these are infectious diseases, such the human immunodeficiency virus, hepatitis B and C viruses, and tuberculosis. Hepatitis G virus is transmissible but may not be a cause of illness. The likelihood of being exposed to these agents appears to be higher in the ED than other medical settings but estimates of the prevalence of these diseases in the ED vary, depending on the patient population served. Estimates of risk for contracting these infections are reviewed. Measures to prevent these exposures can reduce risk, but compliance is low, particularly for those involving changes in the behavior of emergency physicians (such as not recapping needles). Latex allergy is a hazard of health care workers. Its prevalence is reported to be quite high, but these findings are difficult to interpret in the absence of a universally accepted definition of the condition. Its prevalence in emergency physicians is not known. Other noninfectious hazards include workplace violence and exposure to nitrous oxide. The health effects of rotating shift work may put emergency physicians at increased risk of coronary artery disease and impaired reproductive health. Emotional stress is another hazard of emergency physicians, and may lead to burnout.

Latex sensitization in spina bifida appears disease-associated

OBJECTIVE

The high prevalence of latex sensitization (up to 80%) in patients with spina bifida (SB) has been attributed to repeated exposure to latex products, whereas disease-associated factors have not been considered.

METHODS

We compared children with SB (n = 21) and children with posthemorrhagic or congenital hydrocephalus (PH, n = 32), all of whom had a ventriculoperitoneal shunt since young age. Latex sensitization, number of operations, atopic history, and total IgE levels were evaluated.

RESULTS

The following characteristics were recorded: age (SB: 52 months, range 1 to 264 months; PH: 71 months, range 1 to 192 months) and mean number of operations (SB: 2. 09; PH: 2.53). Of the SB group, 43% (9 of 21) showed elevated latex-specific IgE antibodies in contrast to 6% (2 of 32) in the PH group (P <.01). Latex-specific IgE antibodies were detected by 1 year of age, and one surgical operation was sufficient to induce latex-specific IgE-antibody production in patients with SB.

CONCLUSIONS

The results suggest that the SB population bears a disease-associated propensity for latex sensitization. Sensitization to latex antigens may occur after the very first contact, arguing for latex avoidance measures from the very beginning of life.

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.

Rubber latex allergy and the endodontic patient

Increasingly, patients with rubber latex allergy are being seen in dental offices. Health care workers, persons allergic to certain foods and those with certain medical histories are potentially latex-sensitive. This article presents the case of a patient with a history of severe rubber latex allergy and the associated management of an endodontically involved tooth. The possibility of the latex allergic patient being sensitive to gutta-percha obturation material is also raised.

Latex allergy

Coined the next major health concern of the decade, allergy to natural rubber latex affects people routinely exposed to rubber products. Groups at highest risk include health care workers, rubber industry workers, and persons who have undergone multiple surgical procedures, especially those with spina bifida. Allergy to latex is a type I, immediate, IgE-mediated reaction, which can lead to anaphylaxis and death. Much of latex research is published in allergy journals. Dermatologists may not be aware of the prevalence, symptoms, risks, diagnosis, and treatment of latex allergy. These topics are the subject of this review. Research concerning antigenic proteins, as well as sources of latex alternatives, is also summarized. (J Am Acad Dermatol 1998;39:1-24.)

LEARNING OBJECTIVE

At the completion of this learning activity, participants should have a clear understanding of the history, biology, epidemiology, mechanism, clinical characteristics, diagnostic work-up, and treatment of latex allergy. Readers should also have a greater understanding of multiple potential allergenic latex proteins and their importance in preventing future latex-sensitization.