Allergic shock to latex and ethylene oxide during surgery for spinal bifida

Severe anaphylactic shock due to ethylene oxide in a patient with myelomeningocele: successful exposure prevention and pretreatment with omalizumab

Ethylene oxide (EO) is a highly reactive gas widely used for sterilization of medical devices, for example, plastic materials and ventriculoperitoneal shunts. Allergic reactions to EO are rare and have been observed mainly in patients during hemodialysis and myelomeningocele patients. We describe severe anaphylaxis to EO in a patient with myelomeningocele during general anesthesia. A detailed description is provided about the prevention measures aimed at reducing exposure to EO including a novel approach by resterilization with plasma. Also, pretreatment with omalizumab was implemented for the first time in such a case. With these measures, further surgeries in our patient were uneventful.

Pathophysiology of shunt dysfunction in shunt treated hydrocephalus

BACKGROUND

We hypothesized that shunt dysfunction in the ventricular catheter and the shunt valve is caused by different cellular responses. We also hypothesized that the cellular responses depend on different pathophysiological mechanisms.

METHODS

Removed shunt material was collected. Macroscopic tissue in the catheters was paraffin-embedded and HE-stained. Valves were incubated with trypsin-EDTA in order to detach macroscopically invisible biomaterial, which was then cytospinned and HE-stained. Associated aetiological and surgical data were collected by reviewing patient files, and ventricular catheter position was examined using preoperative radiology (CT scans).

RESULTS

We examined eleven ventricular catheters and ten shunt valves. Catheters: 6/11 catheters contained intraluminal tissue consisting of vascularised glial tissue and inflammatory cells (macrophages/giant cells and a few eosinophils). Catheter adherence correlated with the presence of intraluminal tissue, and all tissue containing catheters had some degree of ventricle wall contact. All obstructed catheters contained intraluminal tissue, except one catheter that was dysfunctional because of lost ventricular contact. Valves: Regardless of intraoperative confirmation of valve obstruction, all ten valves contained an almost uniform cellular response of glial cells (most likely ependymal cells), macrophages/giant cells, and lymphomonocytic cells. Some degree of ventricle wall catheter contact was present in all examined valves with available radiology (9/10).

CONCLUSIONS

The same cellular responses (i.e., glial cells and inflammatory cells) cause both catheter obstruction and valve obstruction. We propose two synergistic pathophysiological mechanisms. (1) Ventricle wall/parenchymal contact by the catheter causes mechanical irritation of the parenchyma including ependymal exfoliation. (2) The shunt material provokes an inflammatory reaction, either nonspecific or specific. In combination, these mechanisms cause obstructive tissue ingrowth (glial and inflammatory) in the catheter and clogging of the valve by exfoliated glial cells and reactive inflammatory cells.

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.

[Anaphylaxis during anaesthesia]

BACKGROUND

Anaphylaxis is a serious life-threatening generalized or systemic hypersensitivity reaction. The aim of this paper is to provide knowledge on how to diagnose, treat and follow up patients with suspected anaphylaxis during general and local anaesthesia.

MATERIAL AND METHODS

The article is based on literature identified through a non-systematic search in PubMed, the Scandinavian Guidelines on anaphylaxis during anaesthesia and on own research.

RESULTS

Anaphylactic symptoms during anaesthesia vary with respect to severity. Manifestations from skin and the cardiovascular and respiratory systems are present simultaneously in approximately 70 % of patients. Early treatment with adrenaline, fluid and extra oxygen may be vital for survival without sequelae. The following patients should be assessed before anaesthesia: those with moderate or serious reactions or with reactions that raise suspicion of allergy which may cause problems in connection with future treatment. Neuromuscular blocking agents are the main cause of IgE-mediated anaphylaxis during anaesthesia in Norway. New research has shown that allergy towards neuromuscular blocking agents can develop after ingestion of cough syrup containing pholcodine (stimulates asymptomatic production of antibodies). These antibodies cause cross-sensibilisation with neuromuscular blocking agents. The cough syrup Tuxi was withdrawn from the Norwegian market during spring 2007.

INTERPRETATION

Allergic reactions during anaesthesia are rare and potentially life-threatening; patients should be followed up and treated in a standardized way.

Age-associated issues in preoperative evaluation, testing, and planning: pediatrics

The author has reviewed recent developments in preoperative assessment and testing, emphasizing issues that are of greatest concern in pediatric patients. Attention to these areas during the process of preoperative preparation and appropriate communication of conditions that may contribute to increased peri-operative risk will provide greater predictability for families, surgeons, and operating room staff. This predictability is an important component to improved patient or family satisfaction and operating room efficiency.

Severe anaphylactic shock without exanthema in a case of unknown latex allergy and review of the literature

We describe a case of severe anaphylactic shock without exanthema in an 8-year-old boy who was undergoing elective surgery for an ileostomy. The boy had a history of four anorectal operations in the newborn period, but no history of allergies. Sudden, profound bronchospasm and cardiorespiratory collapse occurred 30 min after the beginning of the operation. No signs of exanthema or urticaria were seen. The patient was resuscitated successfully and remained ventilated for 25 h. During this time, he needed epinephrine in dosages of 0.3-0.05 microg.kg-1.min-1. Radioallergosorbent (RAST) tests for the patient were positive Cap Class 3 and 4, and specific immunoglobulin E was highly positive, suggesting a natural rubber latex allergy as the cause of the anaphylactic shock. Ethylene oxide was negative. Eleven days later, a further operation was performed with a strict latex-free protocol in the presence of histamine 1 and 2 receptor antagonists. On this occasion, the intraoperative course was uneventful. Incidence of anaphylactic reactions, prevalence of latex sensitization, special risk groups and management are discussed.

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.

Perioperative management issues in pediatric patients

Recent developments in perioperative practice, emphasizing issues that are of greatest concern in pediatric patients, are reviewed in this article. Many areas bear further evaluation in the evolving field of perioperative medicine: Effective techniques of psychologic preparation for children and their parents in an era in which the family rarely encounters the hospital environment before the day of surgery Application of newer intraoperative anesthetics, such as new narcotics and muscle relaxants, to shorten PACU and pediatric ICU stay while maintaining safety and comfort Critical evaluation of current methods of pain management to optimize comfort, while minimizing cost of such management in an increasingly cost-conscious health care environment The recent advent of a process for credentialing pediatric anesthesia fellowship programs, which requires a research component, bodes well for the prospect of finding answers to some of these questions.

The search of latex sensitization in spina bifida: diagnostic approach

BACKGROUND

Sensitization to latex has become a major problem in children with spina bifida. Life-threatening reactions may occur in these patients, therefore the search of latex sensitization must be an active task in all of these children.

OBJECTIVE

To design an approach for the diagnosis of latex sensitization in children with spina bifida.

METHODS

We studied 100 consecutive unselected patients. Skin prick tests with a commercial latex extract were performed, latex-specific serum immunoglobulin (Ig) E was determined by CAP test, and risk factors were studied. Originally, patients with an area of latex skin test > 50% of the area of histamine and/or CAP class > or = 3 were considered sensitized to latex. Diagnostic tests were also performed in a control group of 51 atopic and nonatopic children.

RESULTS

After performing a receiver-operating characteristics curve for both tests we recommend skin tests > 25% of the area of histamine (sensitivity - SEN = 79%, specificity - SPE = 100%, positive predictive value - PPV = 100%, negative predictive value - NPV = 90%), or CAP class > or = 2 (SEN = 88%, SPE = 100%, PPV = 100%, NPV = 94%) as diagnostic cut-off points. The anamnesis had a SEN of 44% for diagnosis, and a SPE of 100%. Latex sensitization was associated with more than 5 operations (OR = 8, 95% CI = 3-21.3), a personal history of atopy (OR = 11.5, 95% CI = 2.3-57.1), and serum total IgE > or = 2 z-units (OR = 4, 95% CI = 1. 6-10).

CONCLUSION

For the routine evaluation of children with spina bifida, we propose a diagnostic algorithm with skin prick tests as a first step and CAP second.

Latex allergy in children: diagnosis and management

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

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.

Latex allergy in non-spina bifida patients: unfamiliar intra-operative anaphylaxis

BACKGROUND

The medical literature has described the prevalence of latex allergy in the spina bifida population and its implications for surgical intervention. We report three cases of severe and unexpected intra-operative anaphylaxis secondary to latex exposure in non-spina bifida patients.

METHODS

A retrospective review of case notes identified three non-spina bifida patients who suffered intra-operative anaphylaxis due to latex allergy. Personal and telephone interview and patient chart review was performed to detail a past history of multiple latex exposure, atopy, the anaphylaxis event and the postoperative outcome.

RESULTS

Three non-spina bifida patients are described. One suffered a cardiopulmonary arrest, the remaining two patients had severe vascular hypotension and airway resistance that was only relieved after administration of vasoconstrictors and bronchodilators. Postoperatively, all three tested strongly positive to latex allergen testing. Each patient had a history of multiple surgical latex exposure and specific allergies or allergic-type symptoms pre-operatively.

CONCLUSION

We believe that the predictors of a severe allergic reaction to latex with surgical exposure in non-spina bifida patients may be similar to those predictors known in the spina bifida population. Identification of such at-risk patients will reduce the risk of significant intra-operative morbidity and possible mortality by the introduction of a latex-free operating environment.

Natural rubber latex allergy: spectrum, diagnostic approach, and therapy

Latex allergy has reached epidemic proportions in the United States and is increasingly recognized as a significant contributor to morbidity and mortality during medical and surgical procedures. Ultimately, many of the affected patients with recognized latex sensitivity and those who are not yet diagnosed will receive treatment for their allergic reactions to latex in emergency departments. Consequently, emergency physicians must have a comprehensive understanding of the etiology, epidemiology, pathogenesis, treatment, and management of these challenging patients. Groups at high risk include spina bifida cystica patients, health care workers, latex industry workers, specific food-allergy patients, and patients with a history of atopy or multiple surgical procedures. Sensitization to latex antigens is commonly encountered in health care workers wearing latex gloves with high latex allergen concentrations and in workers using powdered latex surgical gloves. Exposure to air-borne allergens and water-soluble IgE reactive latex antigens from natural rubber latex products in sensitized individuals can result in type I (immediate) hypersensitivity reactions. Clinical manifestations include contact urticaria, dermatitis, allergic rhinitis, conjunctivitis, asthma, angioedema, and anaphylaxis. Diagnostic tools include serological assays and skin prick testing. At present, latex avoidance is the only available treatment and is the key to preventing allergic reactions in latex-sensitized individuals. Health care worker sensitization to latex antigens in natural rubber products is becoming an increasing contributor to workers' liability and disability claims. Specific action can be taken to reduce occupational and patient exposure to latex antigens.

Do latex precautions in children with myelodysplasia reduce intraoperative allergic reactions?

Children with myelodysplasia have an increased incidence of latex allergy, which can lead to severe intraoperative allergic reactions. Despite widespread recommendations to avoid intraoperative latex exposure, little evidence exists to support the efficacy of this practice. We examined the incidence of intraoperative allergic reactions in children with myelodysplasia who underwent 1,025 operations in a 36-month period before and after institution of a standardized latex-avoidance protocol. Risk factors for an intraoperative reaction were found to be a history of latex allergy (p = 0.001) and surgery performed before institution of the latex-avoidance protocol (p = 0.01). The estimate of increased risk for allergic reaction was 3.09 times higher in cases performed without latex avoidance. Recognized violation of the protocol after its institution led to severe allergic reactions in three patients. Our experience suggests that a latex-avoidance protocol reduces intraoperative allergic reactions in children with myelodysplasia. Development of severe allergic reactions with violation of the protocol reinforces the importance of vigilance on the part of all operating room personnel in its implementation.

Latex allergy in the operating room: case report and a brief review of the literature

A patient with a history of spina bifida and cerebral palsy was anesthetized for an ileal conduit. The procedure was uneventful until penetration of the abdominal cavity, immediately after which the patient suffered severe hypotension and her peak inspiratory pressure doubled. The patient's skin became flushed and the capnogram tracing was consistent with bronchospasm. The patient was treated with phenylephrine hydrochloride (Neo-Synephrine), and then epinephrine. This was followed with an epinephrine infusion, intravenous (i.v.) methylprednisolone sodium succinate (Solu-Medrol), inhaled albuterol sulfate, and diphenhydramine hydrochloride (Benadryl) i.v.. The patient responded to these interventions and the procedure was completed without further incident. A diagnosis of latex allergy was made based on the patient's clinical status, underlying diseases, and positive postoperative radioallergosorbent test (RAST). Anesthesiologists must be able to diagnose the signs and symptoms of allergic reactions in patients under anesthesia. This article will review the types of hypersensitivity reactions involved, define the risk groups, and examine the treatment protocols available for latex allergy.

Latex allergy: recognition and perioperative management

Because more than 40,000 household and medical products now contain latex, it is difficult if not impossible to avoid. Repeated exposure to latex leads to increased sensitization in susceptible people, resulting in significant, sometimes life-threatening problems. Health care workers need to be aware of latex allergy for their patients' protection, as well as their own. Proper identification of a potential or known latex allergy, awareness and avoidance of products containing latex, and appropriate perioperative management can avert the tragedy of anaphylactic shock and death.

Intraoperative anaphylaxis due to exposure to latex (natural rubber) in children

Intraoperative anaphylaxis secondary to exposure to latex is a serious and potentially life-threatening phenomenon that has been recognized more frequently in recent years. Between 1989 and 1992, twenty-one patients had a Type-I (anaphylactic) reaction to latex intraoperatively at The Children's Hospital of Philadelphia. Twelve (57 per cent) of these patients had spina bifida. Six patients (29 per cent) had cerebral palsy, and five of them had a ventriculoperitoneal shunt. Of the remaining three patients, one (5 per cent) had exstrophy of the bladder, one had VATER syndrome, and one had Duchenne muscular dystrophy. All of the patients had had at least two previous operative procedures. Overall, sixteen patients (76 per cent) had a ventriculoperitoneal shunt. The manifestations of the allergic reaction included a rash in fifteen patients (71 per cent), hypotension in fifteen, tachycardia in eleven (52 per cent), bronchospasm in ten (48 per cent), bradycardia in two (10 per ent), and cardiac arrest in two. The symptoms occurred within minutes after the induction of the anesthesia in all but one patient, in whom hypotension and cardiovascular arrest developed approximately one hour after the beginning of the operation. Two patients had a full cardiopulmonary arrest while under the anesthesia. All twenty-one patients responded to management; there were no deaths. Of the six patients who had cerebral palsy, five had been managed with a ventriculoperitoneal shunt because of hydrocephalus following a previous intraventricular hemorrhage that was related to prematurity.(ABSTRACT TRUNCATED AT 250 WORDS)

A cluster of anaphylactic reactions in children with spina bifida during general anesthesia: epidemiologic features, risk factors, and latex hypersensitivity

BACKGROUND

Anaphylactic reactions (ARs) in high-risk pediatric patients undergoing general anesthesia, especially those with spina bifida, have been attributed to anesthetics, muscle relaxants, antimicrobials, ethylene oxide, and latex.

METHODS

To identify risk factors for AR during general anesthesia and to investigate the role of latex allergy, we studied epidemiologic and immunologic characteristics of patients with ARs during general anesthesia during a 13-month cluster of such reactions at Children's Hospital of Wisconsin (case patients). Patients with AR were compared with patients with spina bifida undergoing uneventful general anesthesia during the same period (control patients). For each case patient and control patient, we conducted a chart review; a parental interview; skin prick testing with latex, anesthetics, aeroallergens, and banana extract; ELISA and RAST for latex-specific IgE; a total serum IgE; and an ELISA for IgE antibody to ethylene oxide.

RESULTS

Anaphylactic reactions occurred exclusively in patients with spina bifida (n = 10) or patients with a congenital urinary tract anomaly (n = 1). Case-patients were more likely than control patients to have a history of asthma (p = 0.002), rubber contact allergy (p = 0.001), food allergy (p = 0.001), rash caused by adhesive tape (p = 0.05), daily rectal disimpaction (p < 0.001), nine or more prior surgical procedures (p < 0.002), latex-specific IgE (p = 0.027), or elevated total serum IgE levels (p = 0.002). Multivariate analysis identified non-white race, rubber contact allergy, history of food allergy, and nine or more surgical procedures as significant independent risk factors. Logistic model equation identified the predicted probability of AR with a sensitivity, specificity, and positive predictive value of 82%, 97%, and 82%, respectively.

CONCLUSIONS

These findings demonstrate that atopy, especially symptomatic latex allergy, is associated with AR during anesthesia in patients with spina bifida. Until a standardized latex test is available, a medical history of immediate rubber contact allergy, non-white race, food allergy, or nine or more prior surgical procedures can identify patients with spina bifida at highest risk for ARs. A complete history, including rubber contact and food allergy, should be compiled on all patients with spina bifida before surgery.

How common is latex allergy? A survey of children with myelodysplasia

To estimate the prevalence of latex allergy among children with myelodysplasia, describe the spectrum of associated clinical symptoms and evaluate potential risk factors for the development of latex sensitization, the authors conducted a survey at a regional spina bifida center. The findings suggest that symptomatic latex allergy is frequent among children with myelodysplasia and that those with a history of allergies and/or multiple surgical procedures are at greatest risk of sensitization. Until a sensitive and specific laboratory test for latex allergy is available, clinical history, especially allergy to balloons, may be an inexpensive and convenient way of identifying patients with myelodysplasia who may be at increased risk of more severe reactions and at whom preventive measures, such as reducing latex exposures and/or administration of prophylactic medications, should be targeted.

Latex anaphylaxis

BACKGROUND

Unexplained vascular collapse, airway obstruction, shock, and death after procedures as innocuous as barium enema or anorectal manometry have recently been shown to be due to allergy to latex and anaphylactoid reaction.

METHOD

To review existing medical literature on latex anaphylaxis and to determine who is most at risk and what methods might best prevent morbidity from this condition.

RESULTS

Those most at risk for this catastrophe are patients whose mucous membranes have been extensively exposed to latex, such as patients with spina bifida who frequently undergo urethral catheterization and individuals who have had many previous operative procedures:

CONCLUSIONS

Avoidance of latex exposure is the best prophylaxis in high-risk groups. Prompt resuscitation is critical once the syndrome becomes clinically apparent.

Evaluation and risk factors of latex allergy in spina bifida patients: is it preventable?

Allergic reactions to latex, varying from urticaria to life-threatening IgE-mediated anaphylaxis, have been described in patients with spina bifida. In a study of 50 patients 60% had a latex allergy identified by history, a radioallergosorbent test and/or a skin prick test. Latex allergic patients had undergone statistically more surgical procedures than nonallergic patients (9.5 versus 6.7) with a p value of 0.03. The presence of latex allergy did not correlate with the number of intra-abdominal procedures (1.9 versus 1.4) or with the number of years on clean intermittent catheterization (7.7 versus 5.9). These results suggest that latex allergy is acquired through multiple exposures due to breakdown of blood tissue barriers. Therefore, we recommend that all patients with spina bifida undergoing surgery be evaluated for latex allergy and that all surgical procedures in spina bifida patients, from the time of birth, be performed in a latex-free environment.

Latex anaphylaxis during spinal surgery in children with myelomeningocele

Intra-operative anaphylaxis to latex involves cutaneous, respiratory and circulatory changes which may prove fatal if not promptly recognized and treated. It is estimated that 18 to 40 per cent of children with spina bifida may be affected by latex allergy. Current tests available lack sufficient sensitivity and specificity to be recommended as routine screening measures, therefore any allergic history in children with myelomeningocele should alert the clinician to the possibility that severe anaphylactic reactions may occur, especially when large mucosal and pleural-peritoneal surfaces are exposed, as noted in the four reported cases. Epinephrine is the drug of choice should a Type 1 reaction occur.

Latex glove reactions found in a dental school

When a survey was distributed to students, faculty and staff of a dental school to determine the incidence of latex glove reactions, 15 percent reported adverse reactions to glove use. The most frequently reported symptom was dermatitis, followed by urticaria, sweating, conjunctivitis and rhinitis.

Drugs and other agents involved in anaphylactic shock occurring during anaesthesia. A French multicenter epidemiological inquiry

An epidemiological inquiry was carried out in departments of anaesthesia and immunology in French University and General Hospitals, as well as among those who were already known to have an allergo-anaesthesia outpatient clinic. This inquiry aimed to find out how many patients had undergone diagnostic investigations after as well as an anaphylactoid reaction during an anaesthetic in 1990 and 1991, as well as the demographic data, the kind of assessment, the accident mechanism and the drugs involved. Twenty-one French centres replied to the questionnaire and a series of 1,585 patients tested over a two-year period was thus collected. There were three female patients to one male. The reactions occurred mostly in the adult (80%), but 9% were observed in children. Allergological tests for IgE-dependent anaphylaxis were the skin tests (21 centres), combined with radioimmunological assays of specific serum antibodies to muscle relaxants (10 centres), propofol (9 centres), latex (5 centres), leukocyte histamine release (9 centres) and human basophil degranulation test (4 centres). The criteria for a positive result were the same for all centres. Among these 1,585 patients, 813 were recognized as having had a reaction of immunological origin (52%). The substances involved were identified in these 813 patients as being muscle relaxants (70%), latex (12.6%), hypnotics (3.6%), benzodiazepines (2.0%), opioids (1.7%), colloids (4.7%), and antibiotics (2.6%). Suxamethonium was responsible for 43% of the IgE-dependent reactions involving a muscle relaxant, vecuronium for 37%, pancuronium for 13%, alcuronium for 7.6%, atracurium for 6.8% and gallamine for 5.6%.(ABSTRACT TRUNCATED AT 250 WORDS)