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

Allergic Reactions to Dental Materials-A Systematic Review

INTRODUCTION

Utility of various dental materials ranging from diagnosis to rehabilitation for the management of oral diseases are not devoid of posing a potential risk of inducing allergic reactions to the patient, technician and dentist. This review aims to develop a systematic approach for the selection and monitoring of dental materials available in the market thereby giving an insight to predict their risk of inducing allergic reactions.

MATERIALS AND METHODS

Our data included 71 relevant articles which included 60 case reports, 8 prospective studies and 3 retrospective studies. The source of these articles was Pub Med search done with the following terms: allergies to impression materials, sodium hypochlorite, Ledermix paste, zinc oxide eugenol, formaldehyde, Latex gloves, Methyl methacrylate, fissure sealant, composites, mercury, Nickel-chromium, Titanium, polishing paste and local anaesthesia. All the relevant articles and their references were analysed. The clinical manifestations of allergy to different dental materials based on different case reports were reviewed.

RESULTS

After reviewing the literature, we found that the dental material reported to cause most adverse reactions in patients is amalgam and the incidence of oral lichenoid reactions adjacent to amalgam restorations occur more often than other dental materials.

CONCLUSION

The most common allergic reactions in dental staff are allergies to latex, acrylates and formaldehyde. While polymethylmethacrylates and latex trigger delayed hypersensitivity reactions, sodium metabisulphite and nickel cause immediate reactions. Over the last few years, due to the rise in number of patients with allergies from different materials, the practicing dentists should have knowledge about documented allergies to known materials and thus avoid such allergic manifestations in the dental clinic.

Role of cross-allergies to latex in clinical routine of anesthesia

STUDY OBJECTIVE

To determine the applicability and reliability of a screening questionnaire to detect patients at high-risk of latex allergy; to assess the importance of other allergies such as profilin allergies (pollinosis) for presence of latex sensitization; and to determine the clinical effectiveness of preemptive avoidance of latex exposure in high-risk patients.

DESIGN

Prospective, clinical trial.

SETTING

Operative theater of a university hospital.

PATIENTS

95 adult patients.

INTERVENTIONS

Patients were preoperatively screened and classified for present latex allergy (high-risk and low-risk group) according to a specially designed screening questionnaire. Anesthesia and surgery in the high-risk group were performed strictly avoiding latex-containing materials. The low-risk group (other allergies including pollinosis) received routine treatment, without latex-avoidance. Effects of latex avoidance or exposure were evaluated by measuring specific IgE titers perioperatively.

MEASUREMENTS AND MAIN RESULTS

According to the questionnaire, 45 patients at high risk were defined. Validity of classification of high-risk patients is supported by significantly higher total IgE and latex and grass profilin specific IgE compared to the low-risk group. There were no significant differences in other profilin-specific IgEs. In one case of severe anaphylactic reaction a drop of latex-specific IgE during surgery could be observed.

CONCLUSION

The questionnaire allowed the identification of most patients at high risk for latex allergy. In isolated pollinosis no changes in any specific IgE levels were detectable. Strict avoidance of perioperative latex exposure in high-risk patients increases safety during anesthesia and surgery.

Latex allergies in the health care worker

A dramatic increase in the incidence of latex allergies in health care workers followed the surge in latex glove use accompanying the rise of human immunodeficiency virus (HIV) in the early 1980s. This increase in latex glove use was driven by the release of Universal Precautions issued by the Centers for Disease Control (CDC) in response to the rise of HIV and other blood-borne pathogens. Efforts to stem allergic responses in the workplace have relied on the substitution of other materials for latex. Unfortunately, there is so much latex in everyday life that avoiding this allergen is exceedingly difficult once one is sensitized. Additionally, there are numerous cross reactants that are present in the environment. The situation is further confounded by the introduction of genetically manipulated foods and agricultural products that contain defense proteins genetically inserted to protect plants from pests and pathogens. Many of these defense proteins are antigens that will cross react with latex. Sensitivity reactions, once developed, may progress to the point at which the health care worker is excluded from working. This report provides an overview of rubber products and cross reactants, allergic reactions, and latex sensitivity for the health care worker.

Danish Anaesthesia Allergy Centre - preliminary results

BACKGROUND

Anaphylactoid reactions in anaesthesia are rare and should ideally be investigated in specialist centres. At Gentofte University Hospital, we established such a centre in 1998 as a joint venture between the Departments of Anaesthesiology and Dermatology. We present the methodology, diagnostic algorithm and preliminary results from our centre.

METHODS

We are open for referral of patients from all of Denmark. Reactions are classified using a three-grade severity scale and all reactions ranging from mild to severe are investigated. Investigations follow a standard step-by-step protocol of in vitro testing and skin testing. Blood samples for tryptase analysis are taken at the time of reaction and a control sample is taken together with samples for specific IgE analysis 2-4 weeks after the reaction. Subsequent skin testing comprises both prick tests and intradermal tests in most cases. Patients are tested with all substances they were exposed to, including antibiotics, colloids, latex and chlorhexidine.

RESULTS

A total of 68 patients have been referred to date (July 2001) and 36 have completed investigations. Positive test results were mainly seen in patients with more severe reactions, and there were more men than women in the group with the most severe reactions. Six patients had positive specific IgE, three for penicillin, two for latex and one for thiopental. In all, 21 patients had positive skin tests to various substances, of whom four men with anaphylactic shock tested positive for chlorhexidine. Only one patient has tested positive to a neuromuscular blocking drug (NMBD) so far.

DISCUSSION

Our preliminary results appear to differ in two ways from results usually found in this field. Firstly, only one patient has tested positive for a NMBD and secondly, we have had four patients with anaphylactic shock who have tested positive for chlorhexidine. Possible reasons for these differences are discussed.

Anaphylaxis during anaesthesia. Results of a two-year survey in France

Between January 1, 1997 and December 31, 1998, 467 patients were referred to one of the allergo-anaesthesia centres of the French GERAP (Groupe d'Etudes des Réactions Anaphylactoïdes Peranesthésiques) network and were diagnosed as having anaphylaxis during anaesthesia. Diagnosis was established on the basis of clinical history, skin tests and/or a specific IgE assay. The most frequent cause of anaphylaxis was a neuromuscular blocking agent (69.2%). Latex was less frequently incriminated (12.1%) than in previous reports. A significant difference was observed between the incidence of anaphylactic reactions observed with each neuromuscular blocking agent and the number of patients who received each drug during anaesthesia in France throughout the study period (P<0.0001). Succinylcholine and rocuronium were most frequently incriminated. Clinical reactions to neuromuscular blocking drugs were more severe than to latex. The diagnostic value of specific IgE assays was confirmed. These results are consistent with changes in the epidemiology of anaphylaxis related to anaesthesia and are an incentive for the further development of allergo-anaesthesia clinical networks.

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.

[Epidemiology of anesthetic anaphylactoid reactions. Fourth multicenter survey (July 1994-December 1996)]

Since 1984 an epidemiological survey of anaphylactoid reactions occurring during anaesthesia has been obtained in France with regular repeated inquiries by the Perioperative Anaphylactoid Reactions Study Group (Gerap). The members of this group collected during the study period cases of patients having suffered from an anaphylactoid reaction and subsequently tested in their allergoanaesthetic outpatient clinic. The three previous surveys published in the Annales françaises d'anesthésie et de réanimation in 1990, 1993 (in English) and 1996 included 1,240, 1,585 and 1,730 patients respectively. The current survey concerned 1,648 patients, tested by the GERAP (38 diagnostic centres) from July 1994 to December 1996. The diagnostic tests for IgE anaphylaxis were cutaneous tests (prick tests and intradermal tests), which minimal dilutions for specific positive skin test were previously determined by comparison with control subjects. The cutaneous tests were performed by all the centres. These tests were associated, in 29 centres, with the detection of specific IgEs against quaternary ammonium compound and inhibition test, and detection of IgEs against propofol, thiopental and latex. Moreover, leukocyte histamine release test was performed in seven centres. The mechanism of the reaction was: anaphylaxis in 692 patients (characteristic clinical symptoms and positive allergological tests), anaphylactoid reactions in 611 patients (characteristic clinical symptoms and negative allergological tests), and other causes in 345 patients (unusual clinical symptoms and negative allergological tests). An immune mechanism was found in 53% of the reactions, with characteristic clinical symptoms occurring during anaesthesia. The 692 cases of anaphylaxis were due to 734 substances (double anaphylaxis in 42 patients): muscle relaxants (61.6%), latex (16.6%), antibiotics (8.3%), hypnotics (5.1%), colloids (3.1%), opioids (2.7%) and others (2.6%) among which aprotinin (four cases) ethylene oxide (five cases) local anaesthetics (two cases). The muscle relaxants implicated in anaphylactic reactions included: vecuronium (n = 130), atracurium (n = 107), suxamethonium (n = 106), pancuronium (n = 41), rocuronium (n = 41), mivacurium (n = 18), and gallamine (n = 9). These results reflected French anaesthetic practice, except for suxamethonium (5% of the French market share of curares). In 70% of the patients who were allergic to one muscle relaxant, cross-sensitivity was found with the other relaxants. The comparison with the three previous surveys confirms that the mechanism of about half of the anaphylatoid reactions occurring during anaesthesia is of immune origin, due to specific IgE antibodies. Muscle relaxants remain the most common cause of anaphylaxis, followed by latex whose incidence seems to decrease, whereas the incidence of anaphylaxis to antibiotics increases. Incidence of reactions to suxamethonium decreased, corresponding however to one quarter of all muscle relaxant anaphylaxis, similar with vecuronium and atracurium. For this survey, more clinical information was obtained in 583 patients, allowing the following conclusions: reactions were always more severe in case of anaphylaxis than nonspecific histamine release; reactions occurred more frequently in females (F/M = 2.5); 17% of patients allergic to a muscle relaxant were never anaesthetized beforehand; a history of reactions during previous anaesthetics was a risk factor for a reaction during subsequent anaesthetics; neither drug allergy nor atopy (except for latex allergy) were a predisposing factor for reactions with anaesthetic agents. Considering that in 1996, 8 million anaesthetics were administered in France, of which 2.5 million included the use of muscle relaxants, the overall incidence for anaphylactic reactions, all agents included, was evaluated as 1 in 13,000 anaesthetics, while the incidence of anaphylaxis to muscle relaxants was 1 in 6,500 anaesthetics.

Latex anaphylaxis causing heart block: role of ranitidine

PURPOSE

Treatment with H2 receptor antagonists may cause the heart to be more susceptible to atrioventricular conduction delay when exposed to an overwhelming insult by histamine released during an anaphylactic reaction. We present the case of a woman, pretreated with ranitidine, who developed 3:1 heart block secondary to latex anaphylaxis. We propose that H2 antagonist premedication alone in patients susceptible to anaphylaxis increases their risk of heart block.

CLINICAL FEATURES

A 38 yr old obese woman with cervical cancer presented for a radical hysterectomy. Systems review yielded a history of sleep apnea, orthopnea, gastroesophageal reflux, and sciatica. Medications included preoperative ranitidine, 150 mg. There was no history of atopy or allergy. Following general anesthesia induction, at the onset of the surgical procedure the patient developed a severe anaphylactic reaction which was heralded by the onset of 3:1 heart block, with decreases in SpO2, P(ET)CO2 and a decrease in systolic blood pressure to 45 mmHg. This was diagnosed as a possible latex reaction and treated using epinephrine boluses and infusion, fluids, 50 mg diphenhydramine, 50 mg ranitidine and 100 mg hydrocortisone. Following a 48 hr stay in the ICU the patient made an uneventful recovery. Allergy testing with intradermal latex injection and increased plasma tryptase levels confirmed a latex anaphylaxis.

CONCLUSION

The use of H2 antagonists alone as a prophylaxis for gastroesophageal reflux may increase the risk of heart block in patients who develop anaphylaxis.

Natural rubber latex allergy

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

Risk of latex allergy from medication vial closures

A latex allergy, like all allergies, is a serious matter that requires special precautions on behalf of patients and healthcare workers. The FDA final rule on the labeling of natural rubber-containing medical devices will assist in the creation of a latex-safe environment for latex-sensitive individuals. Currently, this ruling does not apply to medication vial closures that contain latex. Until further action by the FDA, the only way to determine whether a medication vial closure contains latex is by directly contacting the pharmaceutical manufacturer. Moreover, in order to rule whether special labeling should be mandatory for latex-containing medication vials, additional evidence is needed to clarify whether exposure to trace amounts of latex from a medication vial stopper can cause allergic reactions in individuals who are sensitive to latex.