[Work-up of penicillin allergy]

Up to 10% of hospitalised patients are registered as penicillin allergic. However, 80-90% will tolerate penicillin after evaluation. New Danish guidelines suggest criteria for evaluation of patients based on risk stratification according to the severity of the index reaction. The allergy label can be removed immediately, if allergy can be ruled out using the criteria presented in this review, but all other patients should be referred for evaluation in a specialist allergy department. Specific IgE measurement should only be done in adult patients with an immediate reaction (onset less-than 2 h after intake of a tablet) or urticaria.

Intradermal Tests With Drugs: An Approach to Standardization

Background: Intradermal tests (IDTs) are performed and interpreted differently in drug allergy centers making valid comparison of results difficult.

Objective: To reduce method-related and intercenter variability of IDTs by the introduction of a standardized method.

Materials and methods: In 11 centers of the European Network for Drug Allergy, IDTs were prospectively performed with saline and with amoxicillin (20 mg/ml) using (1) the local method and (2) the standardized European Network in Drug Allergy (ENDA) method (0.02 ml). The diameters of the initial injection wheal (Wi) for the different volumes and sites injected obtained from each center were analyzed.

Results: The most reproducible method was to fill a syringe with test solution, then expel the excess fluid to obtain exactly 0.02 ml. The median Wi diameter with 0.02 ml injection using the standardized method was 5 mm [range 2–10 mm; interquartile range (IQR) 5–5 mm; n = 1,096] for saline and 5 mm (range 2–9 mm; IQR = 4.5–5 mm; n = 240) for amoxicillin. IDT injection sites did not affect the Wi diameter. Training improved precision and reduced the variability of Wi diameters.

Conclusion: Using the standardized IDT method described in this multicenter study helped to reduce variability, enabling more reliable comparison of results between individuals and centers.

A EAACI drug allergy interest group survey on how European allergy specialists deal with β-lactam allergy

An accurate diagnosis of β-lactam (BL) allergy can reduce patient morbidity and mortality. Our aim was to investigate the availability of BL reagents, their use and test procedures in different parts of Europe, as well as any differences in the diagnostic workups for evaluating subjects with BL hypersensitivity. A survey was emailed to all members of the EAACI Drug Allergy Interest Group (DAIG) between February and April 2016, and the questionnaire was meant to study the management of suspected BL hypersensitivity. The questionnaire was emailed to 82 DAIG centres and answered by 57. Amoxicillin alone or combined to clavulanic acid were the most commonly involved BL except in the Danish centre, where penicillin V was the most frequently suspected BL. All centres performed an allergy workup in subjects with histories of hypersensitivity to BL: 53 centres (93%) followed DAIG guidelines, two national guidelines and two local guidelines. However, there were deviations from DAIG recommendations concerning allergy tests, especially drug provocation tests. A significant heterogeneity exists in current practice not only among countries, but also among centres within the same country. This suggests the need to re-evaluate, update and standardize protocols on the management of patients with suspected BL allergy.

EAACI guidelines on allergen immunotherapy: Hymenoptera venom allergy

Hymenoptera venom allergy is a potentially life-threatening allergic reaction following a honeybee, vespid, or ant sting. Systemic-allergic sting reactions have been reported in up to 7.5% of adults and up to 3.4% of children. They can be mild and restricted to the skin or moderate to severe with a risk of life-threatening anaphylaxis. Patients should carry an emergency kit containing an adrenaline autoinjector, H₁ -antihistamines, and corticosteroids depending on the severity of their previous sting reaction(s). The only treatment to prevent further systemic sting reactions is venom immunotherapy. This guideline has been prepared by the European Academy of Allergy and Clinical Immunology's (EAACI) Taskforce on Venom Immunotherapy as part of the EAACI Guidelines on Allergen Immunotherapy initiative. The guideline aims to provide evidence-based recommendations for the use of venom immunotherapy, has been informed by a formal systematic review and meta-analysis and produced using the Appraisal of Guidelines for Research and Evaluation (AGREE II) approach. The process included representation from a range of stakeholders. Venom immunotherapy is indicated in venom-allergic children and adults to prevent further moderate-to-severe systemic sting reactions. Venom immunotherapy is also recommended in adults with only generalized skin reactions as it results in significant improvements in quality of life compared to carrying an adrenaline autoinjector. This guideline aims to give practical advice on performing venom immunotherapy. Key sections cover general considerations before initiating venom immunotherapy, evidence-based clinical recommendations, risk factors for adverse events and for relapse of systemic sting reaction, and a summary of gaps in the evidence.

Registration of Diagnoses in the Danish National Registry of Patients

The data recorded in the National Registry of Hospitalized Patients in Denmark (Landspatient-registeret [LPR]) are based on reports from the somatic departments of hospitals throughout the country. For the purpose of evaluating the quality of these data, information from LPR concerning patient diagnoses was compared with corresponding information in the records from 924 consecutive admissions to the Frederiksborg County Hospital, Hiller0d. The diagnoses in these records were registered and given priority based on predetermined criteria for selection of primary and secondary diagnoses, respectively. For each hospitalized case a total of 4 primary and 4 secondary diagnoses might be registered. In order to show the variation in choice of diagnoses between physicians, all records from the two medical departments and 10% from the remaining departments were revised by two different physicians. In the medical “block” (medical departments B and F, and the departments of physical medicine, paediatrics, and neurology), there was agreement between the two physicians on at least one of the maximally 4 primary diagnoses which could be registered in 92% of the cases (2-digit code). For the surgical “block” (the departments of parenchymal surgery, orthopaedic surgery, gynaecology, and otology), the corresponding figure was 95%. If the two coders were in agreement on at least one primary diagnosis, this was identical with LPR’s primary diagnosis in 76% of the cases in the medical “block” and 85% of the cases in the surgical “block” (2-digit code). However, in the case of 15% of the medical and 7% of the surgical cases, the primary diagnosis, on which the two coders were in agreement, was not recorded at all by LPR (3-digit code).

It is to be emphasized that a certain variation between different physicians in their choice of diagnoses cannot be eliminated. In conclusion, the level of agreement between LPR and the study material found in the present study is in general satisfactory if LPR’s function as a basis of information for policy making in the hospital sector is taken into consideration. On the other hand, agreement (especially on medical records) is presumably not good enough in LPR to be used for research purposes.

Allergen immunotherapy for insect venom allergy: a systematic review and meta-analysis

BACKGROUND

The European Academy of Allergy and Clinical Immunology (EAACI) is in the process of developing the EAACI Guidelines on Allergen Immunotherapy (AIT) for the management of insect venom allergy. To inform this process, we sought to assess the effectiveness, cost-effectiveness and safety of AIT in the management of insect venom allergy.

METHODS

We undertook a systematic review, which involved searching 15 international biomedical databases for published and unpublished evidence. Studies were independently screened and critically appraised using established instruments. Data were descriptively summarized and, where possible, meta-analysed.

RESULTS

Our searches identified a total of 16 950 potentially eligible studies; of which, 17 satisfied our inclusion criteria. The available evidence was limited both in volume and in quality, but suggested that venom immunotherapy (VIT) could substantially reduce the risk of subsequent severe systemic sting reactions (OR = 0.08, 95% CI 0.03-0.26); meta-analysis showed that it also improved disease-specific quality of life (risk difference = 1.41, 95% CI 1.04-1.79). Adverse effects were experienced in both the build-up and maintenance phases, but most were mild with no fatalities being reported. The very limited evidence found on modelling cost-effectiveness suggested that VIT was likely to be cost-effective in those at high risk of repeated systemic sting reactions and/or impaired quality of life.

CONCLUSIONS

The limited available evidence suggested that VIT is effective in reducing severe subsequent systemic sting reactions and in improving disease-specific quality of life. VIT proved to be safe and no fatalities were recorded in the studies included in this review. The cost-effectiveness of VIT needs to be established.

Drug allergy passport and other documentation for patients with drug hypersensitivity - An ENDA/EAACI Drug Allergy Interest Group Position Paper

The strongest and best-documented risk factor for drug hypersensitivity (DH) is the history of a previous reaction. Accidental exposures to drugs may lead to severe or even fatal reactions in sensitized patients. Preventable prescription errors are common. They are often due to inadequate medical history or poor risk assessment of recurrence of drug reaction. Proper documentation is essential information for the doctor to make sound therapeutic decision. The European Network on Drug Allergy and Drug Allergy Interest Group of the European Academy of Allergy and Clinical Immunology have formed a task force and developed a drug allergy passport as well as general guidelines of drug allergy documentation. A drug allergy passport, a drug allergy alert card, a certificate, and a discharge letter after medical evaluation are adequate means to document DH in a patient. They are to be handed to the patient who is advised to carry the documentation at all times especially when away from home. A drug allergy passport should at least contain information on the culprit drug(s) including international nonproprietary name, clinical manifestations including severity, diagnostic measures, potential cross-reactivity, alternative drugs to prescribe, and where more detailed information can be obtained from the issuer. It should be given to patients only after full allergy workup. In the future, electronic prescription systems with alert functions will become more common and should include the same information as in paper-based documentation.

Insect Sting Reactions and Specific IgE to Venom and Major Allergens in a General Population

BACKGROUND

Insect sting reactions are frequently reported, but population studies documenting the frequency and the relation to IgE-sensitization and serum tryptase are scarce.

METHODS

Questionnaire data and results from measurements of specific IgE against venom, major allergens and cross-reacting carbohydrate determinants (CCDs) were collected from 2,090 adult participants in a cross-sectional survey.

RESULTS

13% of the population reported symptoms of sting reactions and about half were systemic in nature. In all, 15% were sensitized to venom but only 31% of these had reacted to stings and only 38% of those with reactions had IgE to venom. In addition, 12% with IgE to venom were double-sensitized (DS), i.e. to both bee and wasp venom. Among DS IgE to major venom allergens, rApi m 1, rVes v 1 and rVes v 5 were negative and of no help in 31%, but 59% could be identified as likely sensitized to bee or wasp. IgE to CCDs occurred in only 0.7%, but 80% of these were DS. Finally, 36% with IgE to CCDs had had symptoms, mostly local. Serum tryptase was not associated with a history of sting reactions.

CONCLUSIONS

In a temperate climate, self-reported insect sting reactions and sensitization to venom are frequent, but in most cases, these are not seen in the same individual. In DS individuals, measurements of IgE to major allergens can be helpful in some but not all cases and additional analyses are needed. IgE to CCDs may have some clinical relevance.

Efficacy and safety of SQ house dust mite (HDM) SLIT-tablet treatment of HDM allergic asthma

INTRODUCTION

In the treatment of house dust mite (HDM) respiratory allergic disease, allergy immunotherapy constitutes an add-on treatment option targeting the underlying immunological mechanisms of allergic disease. However, for the treatment of HDM allergic asthma, the use of subcutaneous allergy immunotherapy (SCIT) has been limited by the risk of systemic adverse events. Thus, sublingually administered allergy immunotherapy (SLIT) has been investigated as a treatment option with an improved tolerability profile that allows for safer treatment of patients with HDM allergic asthma.

AREAS COVERED

In this Drug Profile, we provide a review of the clinical data behind the SQ HDM SLIT-tablet, which was recently approved for the treatment of HDM allergic asthma and allergic rhinitis by regulatory authorities in several European countries. Expert commentary: The SQ HDM SLIT-tablet is the first allergy immunotherapy to be tested prospectively in patients with asthma, and to favorably modify patient relevant end points such as requirement for inhaled corticosteroid (ICS) or the time to first asthma exacerbation upon ICS reduction, suggesting that SQ HDM SLIT-tablet treatment may contribute to improving overall asthma control.

Self-medication of anaphylactic reactions due to Hymenoptera stings-an EAACI Task Force Consensus Statement

An anaphylactic reaction due to a Hymenoptera sting is a clinical emergency, and patients, their caregivers as well as all healthcare professionals should be familiar with its recognition and acute management. This consensus report has been prepared by a European expert panel of the EAACI Interest Group of Insect Venom Hypersensitivity. It is targeted at allergists, clinical immunologists, internal medicine specialists, pediatricians, general practitioners, emergency department doctors, and any other healthcare professional involved. The aim was to report the scientific evidence on self-medication of anaphylactic reactions due to Hymenoptera stings, to inform healthcare staff about appropriate patient self-management of sting reactions, to propose indications for the prescription of an adrenaline auto-injector (AAI), and to discuss other forms of medication. First-line treatment for Hymenoptera sting anaphylaxis is intramuscular adrenaline. Prescription of AAIs is mandatory in the case of venom-allergic patients who suffer from mast cell diseases or with an elevated baseline serum tryptase level and in untreated patients with a history of a systemic reaction involving at least two different organ systems. AAI prescription should also be considered in other specific situations before, during, and after stopping venom immunotherapy.

Allergen immunotherapy for insect venom allergy: protocol for a systematic review

Background

The European Academy of Allergy and Clinical Immunology (EAACI) is in the process of developing the EAACI Guidelines for Allergen Immunotherapy (AIT) for the Management of Insect Venom Allergy. We seek to critically assess the effectiveness, cost-effectiveness and safety of AIT in the management of insect venom allergy.

Methods

We will undertake a systematic review, which will involve searching international biomedical databases for published, in progress and unpublished evidence. Studies will be independently screened against pre-defined eligibility criteria and critically appraised using established instruments. Data will be descriptively and, if possible and appropriate, quantitatively synthesised.

Discussion

The findings from this review will be used to inform the development of recomendations for EAACI’s Guidelines on AIT.

No evidence for contraindications to the use of propofol in adults allergic to egg, soy or peanut†

BACKGROUND

Propofol is thought to be a potential cause of allergic reactions in patients allergic to egg, soy or peanut, since current formulations contain an emulsion that includes egg lecithin and soybean oil. However, other than six case reports lacking in confirmatory evidence of an allergic reaction, there is no evidence linking the two types of allergies. The aim of this study was to examine the frequency of propofol allergy and to investigate if patients with specific immunoglobulin E (IgE) to egg, soy or peanut tolerated propofol.

METHODS

Study A examined the frequency of propofol allergy in 273 patients systematically investigated for suspected perioperative allergic reactions. Of these, 153 had been exposed to propofol and underwent skin tests and intravenous provocation. Study B retrospectively investigated propofol exposure and tolerance in 520 adult patients with a positive specific IgE to egg, soy or peanut.

RESULTS

Four of the 153 propofol-exposed patients (2.6%) investigated in study A were diagnosed with propofol allergy. Of these, three tested positive only on intravenous provocation. None of the four had allergic symptoms when eating egg, soy or peanut and none had detectable levels of specific IgE to egg or soy in their serum. In study B we found no signs of allergic reactions towards propofol in 171 retrieved anaesthetic charts from 99 patients with specific IgE to egg, soy or peanut.

CONCLUSION

No connection between allergy to propofol and allergy to egg, soy or peanut was found. The present practice of choosing alternatives to propofol in patients with this kind of food allergy is not evidence based and should be reconsidered.

Clinical and diagnostic features of perioperative hypersensitivity to cefuroxime

INTRODUCTION

The Danish Anaesthesia Allergy Centre (DAAC) investigated 89 adult patients with suspected perioperative cefuroxime-associated hypersensitivity reactions between 2004 and 2013. The goals were to determine whether the time to index reaction after cefuroxime exposure could be used to implicate cefuroxime as the cause of the reactions and explore different test modalities in diagnosing cefuroxime hypersensitivity.

METHOD

Skin tests, in vitro tests, and titrated provocations were used to determine cefuroxime hypersensitivity. Patients were deemed cefuroxime positive on the basis of at least two positive tests and/or a positive provocation.

RESULTS

One or more tests were positive for cefuroxime in 24 of 89 (27.0%) patients. One was only specific IgE positive and was deemed cefuroxime negative. Twenty-three (25.8%) were deemed cefuroxime positive. There were four specific IgE-, 4 histamine release test-, 13 skin test-, and 14 provocation positive patients. There were eight (34.8%) patients who were only provocation positive. Data on time to index reaction after cefuroxime exposure were available for 80 patients (22 in the positive group and 58 in the negative group), 22 of 22 (100%) of positive patients reacted in <15 min vs. only 38 of 58 (65.5%) of negative patients.

CONCLUSION

All patients with confirmed hypersensitivity to cefuroxime reacted within 15 min of administration, but so did 65.5% of Cefuroxime negative patients, making timing of administration an unreliable predictor of causation in the perioperative setting. Provocations were always positive when carried out in skin test positive patients; however, eight patients had positive provocations only, highlighting the need for provocation in skin test negative patients.

Drug hypersensitivity in clonal mast cell disorders: ENDA/EAACI position paper

Mastocytosis is a clonal disorder characterized by the proliferation and accumulation of mast cells (MC) in different tissues, with a preferential localization in skin and bone marrow (BM). The excess of MC in mastocytosis as well as the increased releasability of MC may lead to a higher frequency and severity of immediate hypersensitivity reactions. Mastocytosis in adults is associated with a history of anaphylaxis in 22-49%. Fatal anaphylaxis has been described particularly following hymenoptera stings, but also occasionally after the intake of drugs such as nonsteroidal anti-inflammatory drugs, opioids and drugs in the perioperative setting. However, data on the frequency of drug hypersensitivity in mastocytosis and vice versa are scarce and evidence for an association appears to be limited. Nevertheless, clonal MC disorders should be ruled out in cases of severe anaphylaxis: basal serum tryptase determination, physical examination for cutaneous mastocytosis lesions, and clinical characteristics of anaphylactic reaction might be useful for differential diagnosis. In this position paper, the ENDA group performed a literature search on immediate drug hypersensitivity reactions in clonal MC disorders using MEDLINE, EMBASE, and Cochrane Library, reviewed and evaluated the literature in five languages using the GRADE system for quality of evidence and strength of recommendation.

SQ house dust mite sublingually administered immunotherapy tablet (ALK) improves allergic rhinitis in patients with house dust mite allergic asthma and rhinitis symptoms

BACKGROUND

House dust mite (HDM) allergy is associated with persistent allergic rhinitis (AR) and allergic asthma.

OBJECTIVE

To investigate the efficacy and safety of a SQ HDM sublingually administered immunotherapy tablet (ALK, Hørsholm, Denmark) in adults and adolescents with HDM respiratory allergic disease and report the AR results.

METHODS

Six hundred four subjects at least 14 years old with HDM AR and mild to moderate HDM allergic asthma were randomized 1:1:1:1 to double-blinded daily treatment with 1, 3, 6 SQ-HDM or placebo. End-of-treatment rhinoconjunctivitis symptoms and medication score were predefined extrapulmonary end points. A subgroup analysis was conducted post hoc in subjects with a total combined rhinitis score (TCRS) > 0 (ie, with AR symptoms and/or AR medication use during the 4-week baseline period). The subgroup was comprised of 498 subjects (82%).

RESULTS

In the subgroup, the absolute difference in end-of-treatment TCRS between 6 SQ-HDM and placebo was -0.78 (95% confidence interval -1.47 to -0.07, relative difference 28.8%, P = .0357). Furthermore, a significant difference was found for the total score of the Rhinitis Quality of Life Questionnaire with Standardized Activities RQLQ(S) and for the individual domains: activities, sleep, non-nose and non-eye symptoms, and nasal symptoms. For the TCRS and Rhinitis Quality of Life Questionnaire score, a dose response was seen, with numerically lower, nonsignificant differences for 1 and 3 SQ-HDM. The predefined analysis for the entire trial population showed no statistically significant difference between the placebo and actively treated groups. No safety concerns were observed.

CONCLUSION

Efficacy in mild to severe AR of 6 SQ-HDM compared with placebo was demonstrated by statistically significant improvements in TCRS and Rhinitis Quality of Life Questionnaire score in subjects with AR present at baseline. The treatment was well tolerated.

TRIAL REGISTRATION

EudraCT, no 2006-001795-20; ClinicalTrials.gov, identifier NCT00389363.

Asthma and respiratory symptoms among hairdressers in Denmark: results from a register based questionnaire study

BACKGROUND

Hairdressers are at risk of developing occupational respiratory disorders due to persulfates and other hairdressing chemicals.

METHODS

A register based questionnaire study comprising 7,840 graduates from hairdressing vocational schools was conducted. The postal questionnaire concerned self-reported asthma, airway symptoms, occupation, smoking, and atopic dermatitis.

RESULTS

A response rate of 67.9% was obtained. The hairdressers reported asthma (11.2%), cough (25.3%), nasal congestion (24.0%), and rhinitis (18.2%). Less than 1/3 of all hairdressers with suspected occupational asthma reported their asthma as an occupational disease to the authorities. In total, 27.3% were daily smokers; the smoking pattern was similar between hairdressers with and without asthma. Local exhaust ventilation was only used consistently by 63.8% for permanent waving and hair coloring procedures.

CONCLUSIONS

Asthma and especially respiratory symptoms were commonly reported by hairdressers, but rarely reported as an occupational disease. Local exhaust ventilation was inconsistently used. Our results underline the need for improved measures to ascertain and prevent occupational asthma in hairdressers.

Standardized testing with chlorhexidine in perioperative allergy--a large single-centre evaluation

BACKGROUND

Perioperative allergic reactions to chlorhexidine are often severe and easily overlooked. Although rare, the prevalence remains unknown. Correct diagnosis is crucial, but no validated provocation model exists, and other diagnostic tests have never been evaluated. The aims were to estimate (i) the prevalence of chlorhexidine allergy in perioperative allergy and (ii) the specificity and sensitivity for diagnostic tests for chlorhexidine allergy.

METHODS

We included all patients investigated for suspected perioperative allergic reactions in the Danish Anaesthesia Allergy Centre during 2004-2012. The following tests were performed: specific IgE (Immunocap® ; Phadia AB, Sweden), histamine release test (HR) (RefLab ApS, Denmark), skin prick test (SPT) and intradermal test (IDT). Positivity criteria were as follows: specific IgE >0.35 kUA/l; HR class 1-12; SPT mean wheal diameter ≥3 mm; IDT mean wheal diameter ≥ twice the diameter of negative control. Chlorhexidine allergy was post hoc defined as a relevant clinical reaction to chlorhexidine combined with two or more positive tests. Based on this definition, sensitivity and specificity were estimated for each test.

RESULTS

In total, 22 of 228 patients (9.6%) met the definition of allergy to chlorhexidine. Estimated sensitivity and specificity were as follows: specific IgE (sensitivity 100% and specificity 97%), HR (sensitivity 55% and specificity 99%), SPT (sensitivity 95% and specificity 97%) and IDT (sensitivity 68% and specificity 100%).

CONCLUSIONS

In patients investigated for suspected perioperative allergic reactions, 9.6% were diagnosed with allergy to chlorhexidine. Using our definition of chlorhexidine allergy, the highest combined estimated sensitivity and specificity was found for specific IgE and SPT.

Standardized quality (SQ) house dust mite sublingual immunotherapy tablet (ALK) reduces inhaled corticosteroid use while maintaining asthma control: a randomized, double-blind, placebo-controlled trial

BACKGROUND

Investigations meeting current standards are limited for the effect of house dust mite (HDM) allergy immunotherapy in asthmatic patients.

OBJECTIVE

This trial investigated the efficacy and safety of a standardized quality (SQ; allergen standardization method proprietary to the trial sponsor) HDM SLIT-tablet (ALK, Hørsholm, Denmark) in adults and adolescents with HDM respiratory allergic disease. This publication reports the results of the endpoints related to asthma.

METHODS

Six hundred four subjects 14 years or older with HDM allergic rhinitis and mild-to-moderate asthma were randomized 1:1:1:1 to double-blind daily treatment with one of 3 active doses (1, 3, or 6 SQ-HDM) or placebo. Their use of inhaled corticosteroid (ICS) was standardized and adjusted at baseline and the end of treatment to the lowest dose providing asthma control. The primary end point was a reduction in ICS dose from the individual subject's baseline dose after 1 year of treatment.

RESULTS

The primary analysis revealed a mean difference between 6 SQ-HDM and placebo in the reduction in daily ICS dose of 81 μg (P = .004). Relative mean and median reductions were 42% and 50% for 6 SQ-HDM and 15% and 25% for placebo, respectively. No statistically significant differences were observed for the other assessed asthma parameters, reflecting the intended controlled status of the trial subjects. The most common adverse events were local reactions in the mouth. The rate and severity of adverse events were higher for 3 and 6 SQ-HDM than for 1 SQ-HDM and placebo.

CONCLUSION

Efficacy in mild-to-moderate asthma of 6 SQ-HDM relative to placebo was demonstrated by a moderate statistically significant reduction in the ICS dose required to maintain asthma control. All active doses were well tolerated.

Transfusion-associated anaphylaxis during anaesthesia and surgery--a retrospective study

BACKGROUND AND OBJECTIVES

Transfusion-associated anaphylaxis (TAA) is a severe adverse reaction reported to occur in 1:9000-90,000 transfusions. According to the Danish Registration of Transfusion Risks (DART), the frequency is 1:300,000 transfusions, which suggests insufficient reporting of TAA in Denmark. Our aims were to identify possible cases of TAA, to characterize their symptoms and tryptase levels and to investigate the reporting of TAA to the haemovigilance systems.

MATERIAL AND METHODS

We reviewed 245 patients with suspected allergic reactions during anaesthesia and surgery, investigated at the Danish Anaesthesia Allergy Centre (DAAC). Based on the outcome of this investigation, the patients were classified as DAAC positive (confirmed hypersensitivity to identified agent, n = 112), or DAAC negative (no confirmed hypersensitivity, n = 133). Data on case history, details of blood transfusion and results of laboratory and clinical investigations were collected. TAA cases were identified according to the recommendations of the International Society of Blood Transfusion (ISBT).

RESULTS

Ten possible TAA cases (30% of all transfused patients) were identified, all DAAC negative. The frequency of elevated serum tryptase, hypotension and male sex was significantly higher among these cases compared with the remaining DAAC negative (P < 0·05), but not different from the DAAC-positive patients. One case had been reported to the Blood Bank haemovigilance system and none to DART.

CONCLUSION

We identified unreported cases of possible TAA, which resembled the DAAC-positive patients with respect to elevated tryptase and symptoms. By applying the ISBT criteria of adverse transfusion reactions, we conclude that TAA during anaesthesia and surgery is likely to be underreported in Denmark.

Skin test concentrations for systemically administered drugs -- an ENDA/EAACI Drug Allergy Interest Group position paper

Skin tests are of paramount importance for the evaluation of drug hypersensitivity reactions. Drug skin tests are often not carried out because of lack of concise information on specific test concentrations. The diagnosis of drug allergy is often based on history alone, which is an unreliable indicator of true hypersensitivity.To promote and standardize reproducible skin testing with safe and nonirritant drug concentrations in the clinical practice, the European Network and European Academy of Allergy and Clinical Immunology (EAACI) Interest Group on Drug Allergy has performed a literature search on skin test drug concentration in MEDLINE and EMBASE, reviewed and evaluated the literature in five languages using the GRADE system for quality of evidence and strength of recommendation. Where the literature is poor, we have taken into consideration the collective experience of the group.We recommend drug concentration for skin testing aiming to achieve a specificity of at least 95%. It has been possible to recommend specific drug concentration for betalactam antibiotics, perioperative drugs, heparins, platinum salts and radiocontrast media. For many other drugs, there is insufficient evidence to recommend appropriate drug concentration. There is urgent need for multicentre studies designed to establish and validate drug skin test concentration using standard protocols. For most drugs, sensitivity of skin testing is higher in immediate hypersensitivity compared to nonimmediate hypersensitivity.

[Indication for adrenalin autoinjector after anaphylaxis]

Anaphylaxis is a potentially fatal hypersensitivity reaction, which should be treated with adrenaline. Patients at risk of recurrent anaphylaxis after the initial episode should be prescribed an adrenalin autoinjector. The patients include persons, who are allergic to insect venom, before they reach the maintenance dose of allergen-specific immunotherapy, persons with food allergy who are at risk of accidental intakes, persons with anaphylaxis induced by low-intensity physical activity, and idiopathic anaphylaxis. The recommended dose of adrenaline is 0.15 mg for children up to 20 kg and 0.30 mg for larger children and adults.

[Suspected allergic reaction during anesthesia requires thorough postoperative investigation]

Allergic reactions during anaesthesia are rare and the cause is seldom immediately obvious. Incorrect guesses for the offending substance can lead to suboptimal management. Furthermore there is a risk of a serious reaction on subsequent exposure to the real allergen. We present a case of suspected allergy to fentanyl investigated at the Danish Anaesthesia Allergy Centre. Allergy to this drug could not be demonstrated by skin tests or challenge. The reaction was due to unspecific histamine release induced by several opioids given at the same time. Future pretreatment with antihistamine was recommended.

Tolerability and efficacy of house dust mite AIT

Sublingual immunotherapy based on grass pollen allergy immunotherapy tablets is an efficacious and well-tolerated treatment for rhinoconjunctivitis, and subcutaneous house dust mite (HDM) immunotherapy is effective against allergic asthma. Three studies have investigated a new ALK tablet for HDM allergy: two studies on tolerability in adults and children, and one on efficacy and safety in adults and adolescents with asthma. Treatment was well tolerated, mainly with mild-to-moderate local reactions pertaining to the administration site, such as temporary oral pruritus. The primary efficacy endpoint was a significant reduction in inhaled corticosteroid dose compared to baseline after 1 year of daily treatment. A positive therapeutic effect on asthma was demonstrated by a reduction of more than 80 μg/day inhaled budesonide for a group receiving six developmental units daily compared to the placebo group.

Tolerability and efficacy of house dust mite AIT

Sublingual immunotherapy based on grass pollen allergy immunotherapy tablets is an efficacious and well-tolerated treatment for rhinoconjunctivitis, and subcutaneous house dust mite (HDM) immunotherapy is effective against allergic asthma. Three studies have investigated a new ALK tablet for HDM allergy: two studies on tolerability in adults and children, and one on efficacy and safety in adults and adolescents with asthma. Treatment was well tolerated, mainly with mild-to-moderate local reactions pertaining to the administration site, such as temporary oral pruritus. The primary efficacy endpoint was a significant reduction in inhaled corticosteroid dose compared to baseline after 1 year of daily treatment. A positive therapeutic effect on asthma was demonstrated by a reduction of more than 80 μg/day inhaled budesonide for a group receiving six developmental units daily compared to the placebo group.

Capsaicin-induced neurogenic inflammation in the skin in patients with symptoms induced by odorous chemicals

BACKGROUND

Intradermal injection of capsaicin induces the axonal release of neuropeptides, vasodilatation and flare, e.g. neurogenic inflammation. The spatial profile of neurogenic inflammation in the skin has been studied in various experimental models. Polarization spectroscopy imaging introduced recently may be used for the quantitative assessment of the temporal profile of neurogenic inflammation expressed as erythema intensity.

PURPOSE

In the present study, we aimed to compare capsaicin-induced erythema intensity with the flare area in patients with symptoms induced by odorous chemicals, thereby comparing the temporal and spatial profiles of neurogenic inflammation.

METHODS

Sixteen patients fulfilling Cullen's criteria for multiple chemical sensitivity (MCS) and 15 eczema (EC) patients with airway symptoms elicited by odorous chemicals were compared with 29 age-matched, healthy controls. Participants were administered two intradermal injections of capsaicin 3.3 and 33μM. Erythema intensity was measured by polarization spectroscopy imaging and flare response was quantified by visual inspection.

RESULTS

Erythema intensity and flare area did not differ between patients and controls, and they were not correlated. Erythema intensity and flare area showed a dose-dependent increase (P<0.05). Erythema intensity increased with age at 3.3μM but not at 33μM capsaicin, whereas the flare area increased with age at both concentrations (P<0.05).

CONCLUSION

Capsaicin-induced erythema intensity and visual flare were normal in patients with MCS and EC patients with airway symptoms from odorous chemicals. Polarized light spectroscopy was a useful method for the measurement of the rapid temporal changes in erythema of experimental reactions.

Exanthema after a stress Tc-99m sestamibi study: continue with a rest sestamibi study?

PURPOSE

  A mild allergic reaction assumed to be caused by injection of Tc-99m sestamibi for a stress myocardial perfusion imaging (MPI) is presented. We want to discuss the risk involved in completing the MPI with another sestamibi injection, and the precautions and possible treatment in case of a further reaction.

MATERIAL AND METHODS

  A patient experienced a maculo-papular exanthema, i.e. a mild, probably allergic, adverse event (AE) after a stress MPI including administration of a dose of Tc-99m sestamibi. A rest MPI was needed to decide whether coronary bypass surgery should be performed. After prophylactic treatment with antihistamine and corticosteroid, an uneventful rest MPI was performed.

DISCUSSION AND CONCLUSION

  International recommendations or guidelines related to treatment of AEs after nuclear medicine studies do not exist. Serious AEs in nuclear medicine are very rare, but anaphylactic reactions have been reported and may be life threatening. If repeated administration of the radio-pharmaceutical must be given, the prophylactic and therapeutic interventions should follow general international guidelines for allergic reactions.

Challenge Test Results in Patients With Suspected Penicillin Allergy, but No Specific IgE

Purpose

Patients with a history of allergic reaction to penicillin, but with no detectable specific IgE, are common and pose a dilemma. Challenge tests are considered to be the diagnostic gold standard. The aim of this study was to identify subgroups of patients with very low risk for reactions who could be safely tested using a more rapid and simple procedure.

Methods

A total of 580 consecutively referred adult patients with a history of non-serious cutaneous allergic reactions to penicillin, but with no IgE, were challenged with therapeutic doses of penicillin V (phenoxymethylpenicillin), penicillin G (benzylpenicillin), or both.

Results

Only 14 of 580 patients had a positive challenge test. In 11 of the 14, a reaction to challenge occurred within 2 hours, and none were anaphylactic. The year of the original reaction was known for 555 patients; a positive challenge was seen in only 0.4% of those with an original reaction >15 years before challenge, but in 4.6% of those with a more recent original reaction (P=0.001). Onset of a reaction within the first day of the original exposure was a predictive factor for a positive challenge (P=0.001) in patients challenged within 15 years of the original reaction.

Conclusions

Among suspected penicillin-allergic patients with non-severe skin reactions and no detectable specific IgE, the subgroup of patients who originally reacted more than 15 years previously had very low risk for reacting to a challenge. The risk was higher in patients with a more recent original reaction, especially if the symptoms had occurred within the first day of exposure.

The capsaicin cough reflex in patients with symptoms elicited by odorous chemicals

Patients with multiple chemical sensitivity and eczema patients with airway symptoms elicited by odorous chemicals have enhanced cough reflex to capsaicin when applying the tidal breathing method. The aims of the present study were to test whether the capsaicin induced cough reflex was enhanced when applying the single breath inhalation method in similar groups of patients with symptoms related to odorous chemicals e.g. other persons wearing of perfume; and to investigate to what extent the reporting of lower airway symptoms influenced the cough reflex. Sixteen patients fulfilling Cullen's criteria for multiple chemical sensitivity and 15 eczema patients with airway symptoms elicited by odorous chemicals were compared with 29 age-matched, healthy controls. We measured C5--the capsaicin concentration causing five coughs or more--using the single breath inhalation test. No difference was found between groups in age, body mass index or pulmonary function. The median C5 were 129 micromol/L (control group), 48 micromol/L (multiple chemical sensitivity patients), 32 micromol/L (eczema patients). The reporting of lower airway symptoms from odorous chemicals was significantly (p<0.05) correlated to increased cough reflex sensitivity to capsaicin, independent of patient group or co-existence of asthma. The results suggest that the C5 is not reliable for diagnosing MCS but C5 can be used to verify presence of lower airway symptoms related to odorous chemicals.

Increased release of histamine in patients with respiratory symptoms related to perfume

BACKGROUND

Environmental perfume exposure may cause respiratory symptoms. Individuals with asthma and perfume contact allergy report such symptoms more frequently than others. However, immunologic mechanisms have not been demonstrated and the symptoms are not associated with IgE-mediated allergy. The study aimed to investigate whether basophils from patients with respiratory symptoms related to perfume released more histamine in the presence of perfume as compared with healthy volunteers.

METHODS

Histamine release was measured by the glass fibre method. Blood was obtained from healthy volunteers (n=20) and patients with respiratory symptoms related to perfume (n=17) attending a dermatological outpatient clinic for patch testing. The effect of an international brand perfume was investigated using the basophil histamine release test with perfume. Furthermore, basophils from a healthy non-atopic donor were incubated with participant's sera and histamine release induced by perfume was measured.

RESULTS

In both groups incremental perfume concentrations showed a positive and significant (P<0.001) dose-response effect on the release of histamine. At the highest perfume concentration, the basophils released significantly (P<0.05) more histamine in patients as compared with healthy volunteers. No difference was found between the groups when sera were incubated with basophils from a healthy non-atopic donor.

CONCLUSION

Perfume induces a dose-dependent non-IgE-mediated release of histamine from human peripheral blood basophils. Increased basophil reactivity to perfume was found in patients with respiratory symptoms related to perfume.

IgE-mediated allergy to chlorhexidine

BACKGROUND

Investigations at the Danish Anesthesia Allergy Centre have included testing for allergy to chlorhexidine since 1999.

OBJECTIVE

To investigate whether measurement of IgE and histamine release confirm an IgE-mediated mechanism for chlorhexidine allergy.

METHODS

Twenty-two patients with clinical history suggestive of chlorhexidine allergy were included. Skin tests with chlorhexidine and tryptase measurements were performed during initial investigations. Sera were analyzed retrospectively for IgE and histamine release (passive sensitization) to chlorhexidine.

RESULTS

Twelve patients were skin test positive and 10 were skin test negative. Of the skin test-positive patients, 11 of 12 had IgE to chlorhexidine and 7 of 11 had a positive histamine release test. None of the skin test-negative patients had specific IgE or positive histamine release to chlorhexidine. Skin test-positive patients had higher median age (64 vs 49 y) and were mainly male (11/12 vs 6/10). In both groups, 8 patients had hypotension, but bronchospasm mainly appeared in skin test-negative patients (1/12 vs 6/10). Reactions occurred more often during urologic surgery in skin test-positive patients (5/12 vs 0/10). Baseline tryptase was higher in skin test-positive patients (median, 11.5 vs 3.7 microg/L), and 6 of 7 patients had elevated IgE to chlorhexidine in serum at the time of reaction.

CONCLUSION

This study confirms that chlorhexidine allergy is IgE-mediated and that measurement of specific IgE and histamine release are good adjuncts to skin testing in patients with clinical history suggesting chlorhexidine allergy.

CLINICAL IMPLICATIONS

IgE and histamine release can be used to support the diagnosis of allergy to chlorhexidine.

The effectiveness of nationally implemented smoking interventions in Denmark

OBJECTIVE

The present study aimed to investigate the effectiveness of smoking cessation interventions at a national level.

METHOD

A systematic follow-up was made of 3628 adults who participated in smoking cessation groups or in individual interventions in different settings in Denmark from January 2001 to March 2002.

RESULTS

The rates of continued abstinence from smoking were estimated as 18% and 16% after 6 and 12 months, respectively, for the 3628 participants from 101 smoking cessation units. Among participants, who accomplished at least 75% of the intervention, the rates of non-smokers after six and twelve months were 23% and 19%, respectively. Five of the investigated factors influenced continued abstinence after 12 months: gender, age, degree of nicotine dependence, the format and the setting of the cessation service.

CONCLUSIONS

The study shows that it is possible to implement uniform smoking cessation interventions at a national level keeping the same abstinence rates as previously achieved in randomized clinical trials. The successful cessation interventions were run by nurses and equivalent staff that had received only 3 days of training and had no other particular therapeutic skills.

Scandinavian Clinical Practice Guidelines on the diagnosis, management and follow-up of anaphylaxis during anaesthesia

The present approach to the diagnosis, management and follow-up of anaphylaxis during anaesthesia varies in the Scandinavian countries. The main purpose of these Scandinavian Clinical Practice Guidelines is to increase the awareness about anaphylaxis during anaesthesia amongst anaesthesiologists. It is hoped that increased focus on the subject will lead to prompt diagnosis, rapid and correct treatment, and standardised management of patients with anaphylactic reactions during anaesthesia across Scandinavia. The recommendations are based on the best available evidence in the literature, which, owing to the rare and unforeseeable nature of anaphylaxis, mainly includes case series and expert opinion (grade of evidence IV and V). These guidelines include an overview of the epidemiology of anaphylactic reactions during anaesthesia. A treatment algorithm is suggested, with emphasis on the incremental titration of adrenaline (epinephrine) and fluid therapy as first-line treatment. Recommendations for primary and secondary follow-up are given, bearing in mind that there are variations in geography and resources in the different countries. A list of National Centres from which anaesthesiologists can seek advice concerning follow-up procedures is provided. In addition, an algorithm is included with advice on how to manage patients with previous suspected anaphylaxis during anaesthesia. Lastly, Appendix 2 provides an overview of the incidence, mechanisms and possibilities for follow-up for some common drug groups.

Cost-effectiveness of the Danish smoking cessation interventions: subgroup analysis based on the Danish Smoking Cessation Database

The cost-effectiveness of smoking cessation interventions is well documented. However, most studies are based on randomized controlled trials (RCTs) and provide little information on the differences between subgroups. This study assessed the relative cost-effectiveness of smoking cessation interventions offered to various subgroups of smokers, based on real-life data. Regression analyses provided information on the factors determining abstinence and costs and led to the formation of relevant subgroups of smokers. Probabilistic Markov modeling was then used to estimate the relative cost-effectiveness of smoking cessation interventions for the entire database population and for the subgroups compared to a no-intervention case. The ICER for the base case population was estimated at 1,358 euro. This is consistent with results from the existing literature. Group simulations showed lower ICERs for men, hospitals, and light smokers and falling ICERs with increasing age. Despite differences in the cost-effectiveness ratios between subgroups our results do not justify any kind of subgroup differentiation in a smoking prevention policy.

Side-effects of allergen-specific immunotherapy: a prospective multi-centre study

BACKGROUND AND OBJECTIVE

The safety of allergen-specific immunotherapy (SIT) is a parameter of great interest in the overall assessment of the treatment. A clinical database was developed in order to obtain early warnings of changes in the frequency and severity of side-effects and sufficient data for the evaluation of possible risk factors.

METHODS

During a 3-year period, four allergy centres in Copenhagen, Denmark, included data from all patients initiating SIT to a common database. Information on initial allergic symptoms, allergens used for treatment, treatment regimens and systemic side-effects (SSEs) during the build-up phase was collected.

RESULTS

A total of 1,038 patients received treatment with 1,709 allergens (timothy, birch, mugwort, house dust mite (HDM), cat, and wasp and bee venom), 23,047 injections in total. Most SIT patients completed the updosing phase without side-effects, but there was a significant difference between allergens: wasp (89%), birch (82%), HDM (81%), cat (74%) and grass (70%) (P=0.004). A total of 582 SSEs were registered in 341 patients. Most side-effects were mild grade 2 reactions (78%). A difference in severity between allergens was observed (P=0.02), with grass giving most problems. The type of allergen but not patient- or centre-related parameters seemed predictive of side-effects.

CONCLUSIONS

Allergen extracts differ in their tendency to produce side-effects. Multi-centre studies like the present one allow more patients to be evaluated, and thereby provide a more efficient surveillance of side-effects. Online Internet-based registration to a central national database of every allergen injection would be an even more powerful tool for evaluation of risk factors and surveillance of side-effects.

Exposure of eyes to perfume: a double-blind, placebo-controlled experiment

Environmental perfume exposure can elicit bothersome respiratory symptoms. Symptoms are induced at exposure levels which most people find tolerable, and the mechanisms are unclear. The aim of the study was to investigate patients with eye and respiratory symptoms related to environmental perfume, by exposing the eyes to perfume in a double-blind, placebo-controlled study.Twenty-one eczema patients with respiratory symptoms elicited by perfume were compared with 21 healthy volunteers in a sex- and age-matched case-control study. The participants completed a symptom questionnaire, and underwent a double-blind, placebo-controlled exposure to perfume. Of the 42 individuals tested, 10 had more eye symptoms (irritation, itching, and tears) during perfume exposure than during placebo exposures, and eight of these individuals (P = 0.07, Fisher's exact test) belonged to the patient group. A true positive eye reaction to perfume was significantly associated with identification of perfume as an active exposure (P < 0.05). In this study, vapor of perfume elicited irritation in the eyes independently of olfaction, but the relative importance of ocular chemoperception in relation to elicitation of respiratory symptoms from common environmental exposures to perfume remains unclear. We investigated the hypothesis of an association between respiratory symptoms related to perfume and ocular perfume sensitivity by exposing the eyes to perfume in a double blind, placebo-controlled experiment. Vapors of perfume provoked symptoms in the relevant eye in some patients and healthy control persons, but under our exposure conditions, ocular chemesthesis failed to elicit respiratory symptoms.

The capsaicin cough reflex in eczema patients with respiratory symptoms elicited by perfume

Respiratory symptoms elicited by perfume are common in the population but have unclear pathophysiology. Increased capsaicin cough responsiveness has been associated with the symptoms, but it is unknown whether the site of the symptoms in the airways influences this association. The aim of this study was to investigate the association between the site of airway symptoms elicited by perfume and cough responsiveness to bronchial challenge with capsaicin. 21 eczema patients with respiratory symptoms elicited by perfume were compared with 21 healthy volunteers in a sex- and age-matched case control study. The participants completed a symptom questionnaire and underwent a bronchial challenge with capsaicin. Lower, but not upper, respiratory symptoms elicited by perfume were associated with increased capsaicin cough responsiveness. Having severe symptoms to perfume (n=11) did not relate to the site of the symptoms in the airways and was not associated with increased capsaicin cough responsiveness. In conclusion, respiratory symptoms elicited by perfume may reflect local hyperreactivity related to defensive reflexes in the airways, and measurements of the capsaicin cough reflex are relevant when patients with lower respiratory symptoms related to environmental perfume exposures are investigated.

Diagnosis of Hymenoptera venom allergy

The purpose of diagnostic procedure is to classify a sting reaction by history, identify the underlying pathogenetic mechanism, and identify the offending insect. Diagnosis of Hymenoptera venom allergy thus forms the basis for the treatment. In the central and northern Europe vespid (mainly Vespula spp.) and honeybee stings are the most prevalent, whereas in the Mediterranean area stings from Polistes and Vespula are more frequent than honeybee stings; bumblebee stings are rare throughout Europe and more of an occupational hazard. Several major allergens, usually glycoproteins with a molecular weight of 10-50 kDa, have been identified in venoms of bees, vespids. and ants. The sequences and structures of the majority of venom allergens have been determined and several have been expressed in recombinant form. A particular problem in the field of cross-reactivity are specific immunoglobulin E (IgE) antibodies directed against carbohydrate epitopes, which may induce multiple positive test results (skin test, in vitro tests) of still unknown clinical significance. Venom hypersensitivity may be mediated by immunologic mechanisms (IgE-mediated or non-IgE-mediated venom allergy) but also by nonimmunologic mechanisms. Reactions to Hymenoptera stings are classified into normal local reactions, large local reactions, systemic toxic reactions, systemic anaphylactic reactions, and unusual reactions. For most venom-allergic patients an anaphylactic reaction after a sting is very traumatic event, resulting in an altered health-related quality of life. Risk factors influencing the outcome of an anaphylactic reaction include the time interval between stings, the number of stings, the severity of the preceding reaction, age, cardiovascular diseases and drug intake, insect type, elevated serum tryptase, and mastocytosis. Diagnostic tests should be carried out in all patients with a history of a systemic sting reaction to detect sensitization. They are not recommended in subjects with a history of large local reaction or no history of a systemic reaction. Testing comprises skin tests with Hymenoptera venoms and analysis of the serum for Hymenoptera venom-specific IgE. Stepwise skin testing with incremental venom concentrations is recommended. If diagnostic tests are negative they should be repeated several weeks later. Serum tryptase should be analyzed in patients with a history of a severe sting reaction.