Intraoperative anaphylaxis: an association with latex sensitivity

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.

Anaphylaxis to ethylene oxide - a rare and overlooked phenomenon?

Spina bifida patients have been reported to be at increased risk of anaphylactic reactions during general anaesthesia. Following a reaction, latex is often incriminated as spina bifida patients are known to have an increased incidence of latex allergy. Ethylene oxide (EO) has recently been suggested to be an alternative cause, but in many cases reported in the literature, it seems that EO has not been considered as a cause. EO is a highly reactive gas widely used to sterilise heat-sensitive medical devices, and traces of EO can be found in many of the same products as latex. We present the case of a spina bifida patient with a known latex allergy, where EO was found to be the cause of an anaphylactic reaction during general anaesthesia. In addition, we describe measures taken during preparation of a subsequent general anaesthesia to minimise exposure to EO. Spina bifida patients seem to be at increased risk of sensitisation against EO due to repeated exposure, but only limited literature is available. To ensure that EO is considered as a cause in these cases, we recommend that testing for latex and EO go hand in hand following an anaphylactic reaction in this high-risk population.

Latex sensitization and allergy in children with spina bifida in Turkey

PURPOSE

The latex allergy is known as a very frequent problem of children with spina bifida (SB). The aim of this prospective study is to determine the frequency of latex sensitization and allergy in Turkish children with SB and to evaluate the related risk factors.

METHODS

We enrolled a total of 175 children and collected them in four groups of patients: children with SB, children who had neurosurgical disorders other than SB, atopic children with allergic diseases, and healthy children as control group. All cases were evaluated for latex sensitivity and allergy with skin prick tests and specific IgE. The diagnosis of latex allergy was confirmed with the latex provocation test.

RESULTS

Ten children with SB, two children with other neurological disorders, and three atopic children with allergic disease were found "sensitized to latex". Among these sensitized children, only one child with SB had latex allergy. Multivariate logistic regression analysis of the children with SB and other neurologic disorders and the whole group of patients showed that skin test positivity, the presence of noncentral nervous system (CNS) surgery, and the number of the operations were significant risk factors for latex sensitization.

CONCLUSIONS

Our study showed that rates of latex sensitivity and allergy in children with SB in Turkey are significantly lower than published rates in literature. We also found that atopy, the presence of non-CNS operations in children with SB and other neurologic disorder, and total number of operations in the whole group of patients are the most important risk factors for latex sensitization.

IgE-mediated latex allergy--an exciting and instructive piece of allergy history

Natural rubber latex represents a potent allergen, which for many years had an important impact on occupational health problems but especially on certain risk groups such as spina bifida. Luckily, these problems decreased when powder-free, latex-poor gloves were introduced. Latest data show that in children with spina bifida, who grew up completely latex-free from birth on, sensitization to NRL as well as clinical relevant allergy significantly decreased. Furthermore, sensitization to aeroallergens also went down and even the prevalence of allergic diseases decreased significantly to rates of the general population. This new data clearly indicates that potent allergens (such as latex) in high-risk groups (such as spina bifida) can induce sensitization spreading, and corresponding avoidance can reverse this development. In conclusion, it can be stated that 'new' allergies can suddenly arise, there are allergen-specific risk groups, local IgE-production is also possible in the CNS, allergen avoidance can be very effective in terms of primary prevention, sensitization spreading can be made reversible by effective prevention, and finally, certain allergies can luckily become history within a relatively short period of time. Furthermore, these new findings clearly end the debate about whether patients with spina bifida have a disease-inherited risk for allergy to NRL and show that the cause is the meningi and the multiple surgical interventions - and therefore sequelae can be reversed by implementing preventive measures.

The management of anaphylaxis in childhood: position paper of the European academy of allergology and clinical immunology

Anaphylaxis is a growing paediatric clinical emergency that is difficult to diagnose because a consensus definition was lacking until recently. Many European countries have no specific guidelines for anaphylaxis. This position paper prepared by the EAACI Taskforce on Anaphylaxis in Children aims to provide practical guidelines for managing anaphylaxis in childhood based on the limited evidence available. Intramuscular adrenaline is the acknowledged first-line therapy for anaphylaxis, in hospital and in the community, and should be given as soon as the condition is recognized. Additional therapies such as volume support, nebulized bronchodilators, antihistamines or corticosteroids are supplementary to adrenaline. There are no absolute contraindications to administering adrenaline in children. Allergy assessment is mandatory in all children with a history of anaphylaxis because it is essential to identify and avoid the allergen to prevent its recurrence. A tailored anaphylaxis management plan is needed, based on an individual risk assessment, which is influenced by the child's previous allergic reactions, other medical conditions and social circumstances. Collaborative partnerships should be established, involving school staff, healthcare professionals and patients' organizations. Absolute indications for prescribing self-injectable adrenaline are prior cardiorespiratory reactions, exercise-induced anaphylaxis, idiopathic anaphylaxis and persistent asthma with food allergy. Relative indications include peanut or tree nut allergy, reactions to small quantities of a given food, food allergy in teenagers and living far away from a medical facility. The creation of national and European databases is expected to generate better-quality data and help develop a stepwise approach for a better management of paediatric anaphylaxis.

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.

Prolonged Cardiovascular Collapse Due to Unrecognized Latex Anaphylaxis

We present a case of a prolonged anaphylactic reaction that occurred in temporal relationship to the administration of cefazolin. Subsequent allergy testing was positive for latex and negative for cefazolin-both unexpected results. Our case illustrates that medications administered before the onset of anaphylaxis should not be assumed to be the causative allergen and that a latex allergy should be considered in the differential diagnosis. Because the etiology of an anaphylactic reaction cannot be immediately determined, patients experiencing intraoperative cardiovascular collapse should be treated in a latex-free environment.

IMPLICATIONS

We describe a patient who experienced latex-induced intraoperative anaphylaxis. The event coincided with antibiotic administration, which prompted us to erroneously assume that the causative allergen was medication related. Allergy to latex must always be considered as a potential culprit of perioperative cardiovascular collapse.

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.

Anaphylactoid reaction to etomidate: report of a case

We report an anaphylactoid reaction to etomidate twice in a 60-year-old male with coronary artery disease and peripheral vascular disease. Following the first anaphylactoid reaction, the patient developed myocardial infarction. In addition, the patient's blood was moderately positive for latex antibodies, which made the differential diagnosis difficult. We concluded that the patient had anaphylactoid reaction to etomidate due to the temporal relationship to induction with the drug. The patient did not manifest similar reaction to other induction drugs used for other surgeries. The patient recovered from both incidents of anaphylactoid reaction to etomidate following intravenous administration of epinephrine and fluids.

Dental management of children with latex allergy

This paper reviews the aetiology, epidemiology and dental management of children with latex allergy. The issue of latex allergy has serious consequences for the dental management of children with one or more of the following risk factors: spina bifida, atopy, first surgery before one year of age, history of multiple surgical procedures, congenital urologic abnormalities, gastrointestinal malformations, hydrocephalus internus, ventriculo-peritoneal shunts, spinal cord injuries, and family history of atopy. Management of latex allergy is based upon the diligent avoidance of latex exposure. Universal use of powder-free low-allergen latex gloves is recommended.

Latex hypersensitivity in spinal cord injured adult patients

Latex hypersensitivity is a major cause of anaphylaxis during anaesthesia. Patients with spina bifida, health care or rubber industry workers have been considered at risk for latex sensitization. By analogy, the existence of other at-risk subsets of patients with latex exposure due to frequent surgical procedures has been suggested. The aim of this study was to evaluate the prevalence of latex sensitization in a cohort of adult patients with spinal cord injury and repeated latex exposure. Forty-two adult patients with spinal cord injury were studied and retrospectively compared to a group of 30 children with spina bifida evaluated using a similar protocol. Patients were administered a questionnaire concerning history of latex hypersensitivity, atopy, and surgical procedures. Latex sensitivity was investigated by skin prick-tests and latex-specific IgE assay. The search for atopy was based on in vivo and in vitro tests against a panel of environmental allergens. No chronic spinal cord injured patient had a history of latex allergy. When compared with spina bifida, the number of surgical procedures was not statistically different. Although not significantly different, the prevalence of atopy was higher in spina bifida patients. The high level of latex sensitization in spina bifida patients contrasted sharply with the absence of sensitization observed on both skin and in vitro tests in patients with spinal cord injury (P<0.0001). This study confirms that adult patients with chronic neurologic defects resulting from spinal cord injury exhibit a low risk of latex sensitization. These results suggest that considering adult patients with repeated surgical procedures as a group at risk for latex sensitization because of a high degree of latex exposure should be re-examined.

In vitro assessment of the mechanical properties of latex and non-latex orthodontic elastics

The increased incidence of latex allergies has led to the development of non-latex orthodontic products. The purpose of this study was to compare the mechanical properties of latex and non-latex orthodontic elastics. The elastics tested were from 2 manufacturers (GAC and Masel) and made of 2 materials (latex and non-latex). The properties tested included cross-sectional area, breaking force, peak load, peak stress, stiffness, modulus, hysteresis, and 24-hour load relaxation. The data were analyzed with 1-sample t tests, an analysis of variance, and the Fisher PLSD test. Between GAC and Masel, the GAC non-latex elastics had greater breaking forces than did the Masel non-latex elastics. The Masel latex elastics had greater breaking forces than did the Masel non-latex elastics. The GAC non-latex elastics showed more viscoelastic properties than both the GAC latex elastics and the Masel non-latex elastics; however, the Masel elastics were more viscoelastic than the GAC elastics. Forces generated by the elastics decreased over 24 hours to an average load approximating 75% of the manufacturers' values (GAC latex, Masel latex, and Masel non-latex elastics) and to 60% for the GAC non-latex elastics. The mechanical properties of the non-latex elastics were not comparable to those of the latex elastics. Therefore, the clinical choice of elastics should be based on the patient's medical history and the specific mechanical properties of the type of elastic.

Pediatric neuroanesthesia. Neural tube defects

Neural tube defects of the brain and spinal cord, among the most common birth defects in the United States, cause neurologic morbidity from the lesions themselves and from associated hydrocephalus and Arnold-Chiari malformation. Because the myelomeningoceles, and encephaloceles are repaired surgically within hours of birth, neonatal anesthetic management with attention to fluids, body temperature, intravenous access, and monitoring is important. Anesthesia for treatment of hydrocephalus and Arnold-Chiari malformation takes into consideration the presence of intracranial hypertension and the need for manipulation of vital structures in the posterior fossa.

Biogel Skinsense N: surgical glove management for latex allergies

Healthcare staff with a high occupational exposure to latex gloves, such as those who work in the operating theatre, have a higher than average incidence of latex allergies. Certain patient groups are also known to be considered "high risk" for latex allergies. When wearing gloves, staff allergic to latex and those working with patients allergic to latex must wear latex-free gloves to protect themselves and their patients. Of all the different types of gloves available--examination, medical or diagnostic--surgical gloves have to meet the highest standards, offering both protection and comfort. However, latex-free surgical gloves have previously lacked some of the "comfort" qualities of natural latex. This article describes appropriate glove management for latex allergies and looks at the new generation of latex-free surgical gloves.

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.

Sudden bronchospasm on intubation: latex anaphylaxis?

I present a case of a patient with a history of cerebral palsy and asthma, living in a group home, who developed acute onset bronchospasm immediately after intubation. The patient developed hypotension 5 minutes after intubation. The bronchospasm lasted 20 minutes, and the case was complicated further by continued hypotension and a pneumothorax. A diagnosis of latex-mediated anaphylaxis was made in the intensive care unit after immunoglobin E (IgE), serum tryptase, and latex-specific IgE antibody were shown to be markedly elevated. This case report demonstrates that immediate onset of bronchospasm on intubation of an asthmatic patient is not always an asthma attack, and that other causes of bronchospasm should be considered in the differential diagnosis. Patients with a history of atopy, including those with a history of asthma, have an increased risk of developing latex sensitivity. It is important to remember that more than one etiology may be responsible for this kind of bronchospasm, and that it may be difficult to differentiate between multiple etiologies of bronchospasm.

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.

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 review for the dental professional

Reactions to latex products are reportedly occurring with an increased frequency both in patients and in health care providers. Natural rubber latex is found in numerous products, and adverse latex reactions range from contact dermatitis to life-threatening anaphylaxis. A complete understanding of the pathophysiology of latex allergy provides the foundation for the proper diagnosis and treatment of patients with latex allergy. This article provides the reader with a review of latex allergy and suggests strategies for the management of patients with latex hypersensitivity.

Latex allergy: a relevant issue in the general pediatric population

Although latex allergy is a widely recognized problem of the pediatric myelomeningocele population and of frequent users of latex products, it is often overlooked in the general pediatric population. The prevalence of latex in common household items and in medical environments increases one's exposure and thus one's possibility of sensitization to latex. Latex allergy may range from mild local reactions such as erythema to more severe systemic reactions such as asthma or anaphylaxis. The immunoglobulin E-mediated mechanism of these reactions has been confirmed serologically by the presence of latex-specific immunoglobulin E with radioallergosorbent testing. Because avoidance of latex is currently the only way to prevent reactions, the identification of household items that contain latex is extremely important. However, because inadvertent exposure to latex is not uncommon, Medic-Alert bracelets and an Epi-Pen should be provided for children allergic to latex. Pediatric nurses should consider latex allergy as a possible diagnosis in situations of unexplained allergic or anaphylactic reactions and should be aware of optimal therapeutic interventions.

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.

[Substances responsible for peranesthetic anaphylactic shock. A third French multicenter study (1992-94)]

Since 1989, the epidemiological survey of anaphylactoid reactions occurring during anaesthesia is obtained in France with repeated inquiries by the Perioperative Anaphylactic Reactions Study Group. The members of this group collect during the study period the cases of patients having suffered from an anaphylactoid reaction and tested in their allergo-anaesthetic outpatient clinic, their characteristics (age, gender), the results of the allergological tests (mechanism, agents responsible for the reactions). The two previous surveys published in the Annales françaises d'anesthesie et de réanimation in 1990 and 1993 included 1,240 and 1,585 patients respectively. The current survey concerned 1,750 patients tested in 27 diagnostic centres, from January 1992 to June 1994. The reactions occurred at all ages, predominantly between 10 and 50 years, the sex-ratio (F/M) was 2.4. Allergological tests carried out to diagnose an immune mechanism for the shock were cutaneous tests in all centres (prick-tests in 21 centres, intradermal tests in 27 centres) using the same dilutions for the tested agents and the same threshold for positivity. Specific IgE antibodies against muscle relaxants, thiopentone and propofol, were measured by radio immunoassays in 20 centres. The leucocyte histamine release test was used in 10 centres. The immune origin of the shock--IgE dependent anaphylaxis--was diagnosed in 1,000 patients (57.8%) and due to 1,030 agents muscle relaxants (59.2%), latex (19%), hypnotics (5.9%), benzodiazepines (2.1%), opioids (3.5%), plasma substitutes (5%), antibiotics (3.1%) and other drugs given during anaesthesia such as aprotinine and protamine (2.2%). Suxamethonium was responsible for 39.3% of muscle relaxant anaphylaxis, vecuronium for 36%, atracurium for 14.5%, pancuronium for 4.8%, gallamine for 3.1% and alcuronium for 2.3%. The latter has been withdrawn from the French market in 1993. These differences in the incidence of reactions are correlated with the clinical use of muscle relaxants in France for vecuronium and atracurium, however not for suxamethonium, responsible for 39% of the reactions but representing only 5% of the muscle relaxants sold in France. The comparison with the two previous surveys confirms that the mechanism of more than half of the anaphylactoid reactions occurring during anaesthesia is of immune origin, due to specific IgE antibodies. It is therefore essential to systematically carry out an allergologic assessment several weeks after the reaction, in order to discard for the subsequent anaesthetics the agent(s) responsible for anaphylaxis. If the muscle relaxants remain the first drugs involved in shock occurring at induction, there is a significant increase in latex shock, as demonstrated by the three epidemiological surveys (0.5%, 12.5% and now 19%). The incidence of other anaesthetic agents, antibiotics and plasma substitutes remains unchanged.

Natural rubber-latex allergy in patients not intensely exposed

Immediate-type allergy to natural rubber latex (NRL) is common in highly exposed groups, particularly in health-care workers and patients with spina bifida. The occurrence of NRL allergy was investigated in subjects not belonging to such risk groups. A total of 493 patients presenting with various diseases for allergologic evaluation was studied. A questionnaire-based history was taken, skin prick tests with NRL milk and common aeroallergens were done, and NRL-specific serum IgE antibodies were measured. A total of 317 subjects (64.3%) was atopic. There were skin prick test reactions to NRL in 80 (16.2%) and NRL-specific IgE in the serum in 79 (16.0%) subjects; both were found in 25 patients (5.1%). Altogether, NRL sensitization was found in 134 patients (27.2%). By history and/or challenge tests, 13 subjects (2.6%) were diagnosed as having clinically relevant NRL allergy. In five of these, anaphylactic reactions had occurred during dental procedures, and in four during general anesthesia; 10 subjects reported immediate-type reactions to NRL products in daily life. All patients with clinically relevant NRL allergy had a skin prick test reaction to NRL milk (sensitivity 100%). Nine had specific IgE antibodies in the serum (sensitivity 69.2%); respective specificity was 86.0% or 85.4%. Nine of the 13 patients (69.2%) with NRL allergy were atopic. Despite exclusion of those at risk, many patients had clinically relevant allergy to NRL, and many of these had had severe reactions. NRL allergy is an important health issue also beyond the known risk groups.

Development of latex allergy in children up to 5 years of age--a retrospective analysis of risk factors

The aim of the study was to investigate possible associations between the time course of early sensitization to latex and various life style factors. Of the 398 children from a prospective birth cohort study, 20 (5%) showed specific serum IgE to latex at the age of 5 years. Sensitization started beyond the first year of life and 19 out of 20 sensitized children showed increasing specific IgE-values over time. All 20 sensitized children were atopic (p < 0.00000). Total IgE was significantly higher in the sensitized group (median 394.5 kU/I) than in the non-sensitized group (median 39.2 kU/l) (p < 0.00001). Comparing the latex-sensitized group with the non-sensitized children, there were significantly more operations in the latex group (p < 0.05) during the first 5 years of life. Medical history, certain foods, the use of pacifiers, mattress composition and socio-economic data proved not to be significant risk factors. From our study we conclude that besides the number of operations and an atopic predisposition--no other definite risk factor for developing sensitization or allergy to latex (such as everyday household objects) can be identified in children up to 5 years of age.

Natural rubber latex allergy in children who had not undergone surgery and children who had undergone multiple operations

BACKGROUND

Children with spina bifida and other children requiring multiple surgical procedures represent a well-known risk group for natural rubber latex allergy. Children not undergoing surgery can also be sensitized, but findings in this group of children with latex allergy have not been thoroughly examined.

OBJECTIVES

We sought to examine the frequency of latex allergy in a large group of children admitted for inhalant or food allergy testing for the purpose of collecting information on a series of children with latex allergy and comparing the symptoms and findings between those not undergoing surgery and those undergoing multiple operations.

METHODS

Children admitted to the allergy laboratory of Tampere University Hospital were screened by skin prick tests (SPTs) with latex glove extract. All children with allergy as determined by the screening or admitted because of suspected latex allergy were reexamined from 1995 to 1996. For a definite diagnosis of latex allergy, positive SPT, latex RAST, and latex glove use test results were required.

RESULTS

From 1992 to 1995, a total of 3269 children were skin prick tested with latex glove extract, and 55 (1.7%) had a positive response. On reexamination, 37 (1.1%) children had positive responses to SPTs, and 33 (1.0%) were confirmed to have latex allergy by means of RASTs and latex glove use tests. Since 1988, we have identified a total of 30 children with latex allergy who had not undergone surgery and 12 who underwent multiple operations. The clinical histories were similar in both groups; the mean ages at diagnosis were 5.7 and 8.1 years, and the frequency of atopy was 97% and 83%, respectively. Symptoms had occurred in 63% of the children who had not undergone surgery and in 75% of the children who underwent multiple operations. Contact urticaria was the most frequent symptom, and only one child had intraoperative anaphylaxis. Balloons, followed by gloves, were the most common latex products causing symptoms. The children with latex allergy who had not undergone surgery and those who underwent multiple operations showed no significant differences in SPT responses to commercial latex allergen extract or in specific IgE levels.

CONCLUSIONS

The prevalence of latex allergy among children admitted for inhalant or food allergy testing was 1%. Although multiple operations at an early age are a well-known risk factor for latex allergy, the majority of children with latex allergy identified at screening or admitted because of suspicion of latex allergy belonged to the group of children who had not undergone surgery. One third of all the children studied were free of symptoms, indicating that screening with SPTs can be a valuable tool for detecting occult latex allergy in children.

Determination of independent risk factors and comparative analysis of diagnostic methods for immediate type latex allergy in spina bifida patients

BACKGROUND

Development of allergy to natural rubber latex in spina bifida patients is determined by several risk factors, such as age, number of interventions and atopic disease that are, however, interdependent. Furthermore, several diagnostic procedures have been analysed, but a comprehensive analysis of their diagnostic significance is lacking.

OBJECTIVE

To determine the independent major risk factor(s) for development of natural rubber latex allergy and the most valuable diagnostic procedure.

METHODS

In aselectively collected spina bifida patients, we correlated existing natural rubber latex allergy with age, sex, atopy and the number of hospitalizations and of surgical interventions in appropriately matched subgroups. Allergy to natural rubber latex was established by application of a latex glove fragment on the skin. Skin-prick tests with glove eluate, a natural latex extract and a commercial latex extract were carried out as were specific IgE measurements by radioimmuno assay (RAST-CAP). The results of the latex application test are compared with the other diagnostic methods.

RESULTS

Out of 74 fully evaluated patients, 17 had a positive application test. The number of surgical interventions correlates strongly with the presence of natural rubber latex allergy (P<0.0002), independent of age, sex and presence of atopy. Skin-prick tests with unstandardized allergens made from known high allergenic latex gloves represent the most sensitive diagnostic method, with the highest negative predictive value and a specificity of 0.95. RAST-CAP was the next best method with a specificity of 0.93, a sensitivity of 0.89 and a negative predictive value of 0.97.

CONCLUSION

The number of surgical interventions is the major independent determining factor for allergy to natural rubber latex in spina bifida patients. Unstandardized skin-prick tests are the most sensitive and specific diagnostic tool, but RAST-CAP is almost equally performant and therefore a valid alternative.

The incidence of latex sensitivity in ambulatory surgical patients: a correlation of historical factors with positive serum immunoglobin E levels

Increasing reports of latex-induced anaphylaxis make preoperative identification of latex-sensitive individuals an important concern. The incidence of latex sensitivity and the efficacy of questionnaires in identifying this in ambulatory surgical populations have not been determined. To clarify these issues, 996 ambulatory surgical patients were studied preoperatively. A questionnaire addressing demographic information, previous surgeries, history of atopy, previous exposure or reactions to latex, congenital abnormalities, and food allergies was administered. These data were then compared with serum anti-latex immunoglobin E (IgE) levels (AlaSTAT test), and risk factors, sensitivity, and specificity were determined. Of this population, 6.7% had IgE antibodies against latex (i.e., latex sensitivity). Male gender, non-Caucasian race, age, asthma, spinal cord abnormalities, food allergies, stated latex allergy, and symptoms when exposed to latex increased the risk of latex sensitivity. The specificity and positive predictive value of history were low. No systemic allergic reactions occurred, a finding that could be attributed to chance alone. The incidence of latex sensitivity in this population suggests that latex allergy is a significant potential problem in ambulatory surgical patients. History, however, does not appear to be a reliable predictor of the presence of anti-latex antibodies.

IgE-mediated hypersensitivity to latex in childhood

A total of 267 children scheduled to receive anesthesia during a surgical, neurosurgical, or orthopedic intervention were investigated. IgE antibodies against latex were detected in serum samples of 6.4% (17/267 children) of the patients. The most important difference between sensitized and nonsensitized children was the number of surgical interventions in the past. The median of surgical interventions was 1.0 in the nonsensitized group of children and 3.0 in the sensitized group. Only 0.9% of the children with up to two surgical interventions and 34.1% with three or more procedures were sensitized to latex. Only one of the sensitized children developed intraoperative anaphylaxis during intervention after our investigation. We conclude that children with a history of three or more surgical interventions have a high risk of sensitization to latex proteins. Nevertheless, the predictive value of IgE antibodies against latex for development of anaphylaxis during anesthesia seems to be low.

Anaphylaxis in children: a 5-year experience

OBJECTIVES

To identify the causative agents, presenting signs and symptoms, and course of disease in children diagnosed with anaphylaxis. Design. Five-year retrospective chart review.

SETTING

Urban children's hospital pediatric emergency department, operating suite, and inpatient units.

PARTICIPANTS

Fifty-five cases of anaphylaxis in 50 patients 1 to 19 years of age.

INTERVENTIONS

None.

RESULTS

The most common inciting agents in this population were latex (27%), food (25%), drugs (16%), and venoms (15%). Thirty-two cases (58%) occurred outside of the hospital, including 3 of 11 severe cases. Nineteen (35%) had histories of prior allergy to the causative agent. Most agent exposures were intravenous (38%), oral (27%), or dermal (20%). The most common systems involved were respiratory (93%), skin (93%), cardiovascular (26%), and neurologic (26%). Features distinguishing the 11 patients requiring intensive care included latex agents (45%), nonenteral route of exposure (91%), and presence of cardiovascular symptoms (45%). Of the 17 patients with known past anaphylaxis, only 5 had epinephrine self-administration devices available, and 3 had used them.

CONCLUSIONS

(1) Most patients with anaphylaxis present with skin or respiratory symptoms. (2) Severely ill children more commonly have nonenteral and/or latex exposures that occur in the hospital. (3) Most children with anaphylaxis have no stated histories of prior reaction to the causative agent. (4) Those patients who have had past episodes of anaphylaxis infrequently have epinephrine self-administration devices available for use.

Prevalence of latex sensitization in a hospital employee population

BACKGROUND

Immediate-type allergic reactions to latex products have become increasingly recognized in hospital workers.

OBJECTIVE

This study was designed to assess the prevalence of latex sensitization by skin testing and specific IgE testing in a group of hospital employees and compare these with each subject's self-reported allergic history.

METHODS

Volunteers were recruited from selected departments. Each was tested with epicutaneous skin test with latex glove extract and commercial environmental allergens, had blood drawn for latex-specific IgE testing (AlaSTAT brand of ELISA), and was given a questionnaire for general and latex allergy history.

RESULTS

There were 135 participants. Eleven (8.2% of sample, 95% confidence interval 3.4% to 13.0%) were skin test positive for latex reagent, and seven of these (5.2% of sample) reported allergic symptoms to latex contact. Testing for latex-specific IgE (ELISA) showed 6.7% with class II or higher reaction. There was high correlation of the two tests, with ELISA showing a sensitivity of 63.6% and a specificity of 98.4% with reference to skin testing. In this sample, 16% reported some upper respiratory symptoms in association with latex contact, although only one-third of this group was skin test positive. Past history of allergic or atopic disease was poorly predictive of skin or blood test reactivity. A reaction to a greater number of environmental allergens was associated with positive latex skin test reactivity.

CONCLUSION

Testing for latex sensitivity in this hospital sample revealed more than 5% of workers developed clinical allergies to latex and continued to remain occupationally in contact with latex. In vitro testing is a potential substitute for the more technically difficult skin testing.

Perioperative collapse: prevalence of latex allergy in patients sensitive to anaesthetic agents

The evidence in the literature suggests that the prevalence of latex allergy in the general population is approximately 1%. With increasing awareness of transmission of HIV and other infections such as hepatitis B, the use of latex gloves and condoms has escalated in recent years. As cheaper latex gloves of variable and doubtful quality flood the market, health care workers and patients are being increasingly sensitized by these latex products. A retrospective study investigated the prevalence of latex allergy in a cohort of 26 patients who suffered perioperative anaphylactoid reactions. 84% of these patients were hypersensitive to at least 1 anaesthetic-related agent. 7.7% were also allergic to latex (p = 0.028). Atopy is a strong predisposing factor (p = 0.006). An accurate preoperative history of atopy and past reactions to latex will identify most at-risk patients. Prick test and RAST to latex will confirm the latex allergy. Anaesthetists, surgeons, allergists and other health practitioners should be aware of this problem.