Peanut-induced anaphylaxis in children and adolescents: Data from the European Anaphylaxis Registry

BACKGROUND

Peanut allergy has a rising prevalence in high-income countries, affecting 0.5%-1.4% of children. This study aimed to better understand peanut anaphylaxis in comparison to anaphylaxis to other food triggers in European children and adolescents.

METHODS

Data was sourced from the European Anaphylaxis Registry via an online questionnaire, after in-depth review of food-induced anaphylaxis cases in a tertiary paediatric allergy centre.

RESULTS

3514 cases of food anaphylaxis were reported between July 2007 - March 2018, 56% in patients younger than 18 years. Peanut anaphylaxis was recorded in 459 children and adolescents (85% of all peanut anaphylaxis cases). Previous reactions (42% vs. 38%; p = .001), asthma comorbidity (47% vs. 35%; p < .001), relevant cofactors (29% vs. 22%; p = .004) and biphasic reactions (10% vs. 4%; p = .001) were more commonly reported in peanut anaphylaxis. Most cases were labelled as severe anaphylaxis (Ring&Messmer grade III 65% vs. 56% and grade IV 1.1% vs. 0.9%; p = .001). Self-administration of intramuscular adrenaline was low (17% vs. 15%), professional adrenaline administration was higher in non-peanut food anaphylaxis (34% vs. 26%; p = .003). Hospitalization was higher for peanut anaphylaxis (67% vs. 54%; p = .004).

CONCLUSIONS

The European Anaphylaxis Registry data confirmed peanut as one of the major causes of severe, potentially life-threatening allergic reactions in European children, with some characteristic features e.g., presence of asthma comorbidity and increased rate of biphasic reactions. Usage of intramuscular adrenaline as first-line treatment is low and needs to be improved. The Registry, designed as the largest database on anaphylaxis, allows continuous assessment of this condition.

Contraindications to immunotherapy: a global approach

BACKGROUND

Recommendations on contraindications to allergen immunotherapy (AIT) have been independently developed by National and International Societies/Academies. AIT contraindications are mainly based on case reports, case-series, or experts' opinion, while evidence-based information is limited. The aim of the present review was to describe existing guidelines on contraindications to AIT and to highlight differences between them.

MAIN BODY

An extended review of the literature regarding contraindications to AIT for respiratory allergy and venom hypersensitivity was performed. Furthermore, Societies and Academies registered in the World Allergy Organization and EAACI databases, were asked for additional information. Only AIT guidelines published under official auspicies were included. A large heterogeneity among the various recommendations on contraindications was registered. Common contraindications to most of the guidelines were: lack of adherence, pregnancy before the start of AIT, the use of beta-blockers, certain age groups, uncontrolled asthma, autoimmune diseases and malignancies.

CONCLUSION

As new data arise, revisions might soon be needed allowing AIT in the cases of patients treated with ACE inhibitors and beta-blockers, in elderly patients and in patients with concomitant autoimmune diseases and neoplasias in remission. The decision to prescribe AIT is always tailor-made, balancing risk vs benefit. Creating globally accepted guidelines would help Allergologists in their decision making.

Factors increasing the risk for a severe reaction in anaphylaxis: An analysis of data from The European Anaphylaxis Registry

BACKGROUND

Preventive measures to decrease the frequency and intensity of anaphylactic events are essential to provide optimal care for allergic patients. Aggravating factors may trigger or increase the severity of anaphylaxis and therefore need to be recognized and avoided.

OBJECTIVE

To identify and prioritize factors associated with an increased risk of developing severe anaphylaxis.

METHODS

Data from the Anaphylaxis Registry (122 centers in 11 European countries) were used in logistic regression models considering existing severity grading systems, elicitors, and symptoms to identify the relative risk of factors on the severity of anaphylaxis.

RESULTS

We identified higher age and concomitant mastocytosis (OR: 3.1, CI: 2.6-3.7) as the most important predictors for an increased risk of severe anaphylaxis. Vigorous physical exercise (OR: 1.5, CI: 1.3-1.7), male sex (OR: 1.2, CI: 1.1-1.3), and psychological burden (OR: 1.4, CI: 1.2-1.6) were more often associated with severe reactions. Additionally, intake of beta-blockers (OR: 1.9, CI: 1.5-2.2) and ACE-I (OR: 1.28, CI: 1.05, 1.51) in temporal proximity to allergen exposition was identified as an important factor in logistic regression analysis.

CONCLUSION

Our data suggest it may be possible to identify patients who require intensified preventive measures due to their relatively higher risk for severe anaphylaxis by considering endogenous and exogenous factors.

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.

Meat allergy associated with galactosyl-α-(1,3)-galactose (α-Gal)-Closing diagnostic gaps by anti-α-Gal IgE immune profiling

BACKGROUND

Glycoproteins and glycolipids of some mammalian species contain the disaccharide galactosyl-α-(1,3)-galactose (α-Gal). It is known that α-Gal is immunogenic in humans and causes glycan-specific IgG and also IgE responses with clinical relevance. α-Gal is part of the IgE-reactive monoclonal therapeutic antibody cetuximab (CTX) and is associated with delayed anaphylaxis to red meat. In this study, different α-Gal-containing analytes are examined in singleplex and multiplex assays to resolve individual sensitization patterns with IgE against α-Gal.

METHODS

Three serum groups, α-Gal-associated meat allergy (MA) patients, idiopathic anaphylaxis (IA) patients with suspected MA, and non-meat-allergic healthy control individuals (HC), were analyzed via singleplex allergy diagnostics and a newly established immunoblot diagnostic system. The new dot blot detection system resolved individual IgE sensitization profiles for α-Gal-containing analytes CTX, bovine thyroglobulin (Bos d TG), and human serum albumin (HSA)-conjugated α-Gal.

RESULTS

Singleplex allergy diagnostics using the α-Gal analytes CTX and Bos d TG confirms the history of MA patients in 91% and 88% of the cases, respectively. A novel dot blot-based assay system for the detection of IgE against α-Gal reveals individual IgE sensitization profiles for α-Gal-containing analytes. An α-Gal-associated IgE cross-reactivity profile (IgE against CTX, Bos d TG, and HSA-α-Gal) was identified, which is associated with MA.

CONCLUSIONS

Detection of individual sensitization patterns with different α-Gal-containing analytes provides the basis for an individual allergy diagnosis for α-Gal-sensitized patients. Higher amounts of α-Gal in pork and beef innards compared to muscle meat as indicated by a higher staining intensity are a plausible explanation for the difference in allergic symptom severity.

Overcoming severe adverse reactions to venom immunotherapy using anti-IgE antibodies in combination with a high maintenance dose

BACKGROUND

An omalizumab treatment and a high maintenance venom dose may both help to prevent recurrent systemic allergic reactions (SAR) to venom immunotherapy (VIT). The effectiveness of this combination therapy, however, is unclear.

OBJECTIVE

We wanted to explore the possibility whether a temporary treatment with the anti-IgE antibody omalizumab combined with a VIT using an elevated maintenance dose of >100 μg venom may establish a permanent tolerance of maintenance VIT.

METHODS

For this retrospective case series, we scoured our institutional data base for patients who had had an insect venom allergy, and in whom it had not been possible to continue VIT because of repeated unstoppable SAR during maintenance VIT. Patients were divided into those who had received the combination therapy (omalizumab group) and those who had not received omalizumab because its costs could not be covered (controls). Guided by the total IgE level and by body weight, omalizumab had been given subcutaneously 5, 3 and 1 weeks before VIT had been restarted. Three to 6 months after an elevated maintenance dose (200-300 μg venom) had been reached, omalizumab had been stopped.

RESULTS

Between 2006 and 2011, 15 patients had qualified for an off-label use of omalizumab: 10 patients had received the combination therapy, and 5 patients had remained without such a therapy. The combination therapy leads to a durable tolerance of VIT in all patients even after omalizumab had been discontinued (median of follow-up time 5.8 years, IQR 2.7-8.6 years). Sting challenge tests were tolerated by all of the re-stung omalizumab patients (n = 8). In all controls, VIT had to be stopped permanently due to repeated SARs (P < .001 vs omalizumab group).

CONCLUSIONS AND CLINICAL RELEVANCE

Combining a temporary omalizumab therapy with an elevated maintenance dose seems a promising approach to achieve a tolerance of treatment in patients with a recurrent SAR to VIT.

BASALIT trial: double-blind placebo-controlled allergen immunotherapy with rBet v 1-FV in birch-related soya allergy

BACKGROUND

Conflicting results exist on the effect of allergen immunotherapy (AIT) on pollen-related food allergy. We aimed to investigate the efficacy of one-year AIT with the folding variant (FV) of recombinant (r) Bet v 1 on birch-related soya allergy.

METHODS

Of 138 subjects with Bet v 1 sensitization, 82 were positive at double-blind placebo-controlled food challenge (DBPCFC) with soya. A total of 56 of 82 were randomized in the ratio of 2:1 (active: placebo). Per-protocol population (PPP) had received ≥150 μg of allergen or placebo preparation.

OUTCOME MEASURES

lowest observed adverse effect levels (LOAEL), postinterventional occurrence of objective signs (objS) at any dose level, sIgE/IgG4 against Bet v 1 and Gly m 4. Between-group changes were investigated (ancova, Mann-Whitney U-test, Fisher exact test).

RESULTS

Baseline characteristics including LOAELs were comparable in both groups with objS and subjS occurring in 82% and 95% of active (n = 38) vs 78% and 83% of placebo group (n = 18). After AIT, objS occurred in 24% and 47%, respectively. LOAEL group differences showed a beneficial tendency (P = 0.081) for LOAELobjective in PPP (30 active, 15 placebo). sIgG4 raised only in active group (Bet v 1: P = 0.054, Gly m 4: P = 0.037), and no relevant changes occurred for sIgE. Only 56% of the intended sample size was recruited.

CONCLUSION

For the first time, we present data on the effect of rBet v 1-FV on birch-related soya allergy. rBet v 1-FV AIT induced significant immunogenic effects. Clinical assessment showed a tendency in favour of the active group but did not reach statistical significance.

H1-antihistamine-refractory chronic spontaneous urticaria: it's worse than we thought - first results of the multicenter real-life AWARE study

BACKGROUND

Most data on chronic spontaneous urticaria (CSU) originate from highly selected patient populations treated at specialized centres. Little is known about CSU patient characteristics and the burden of CSU in routine clinical practice. AWARE (A World-wide Antihistamine-Refractory chronic urticaria patient Evaluation) is an ongoing global study designed to assess chronic urticaria in the real-life setting.

OBJECTIVE

To describe the baseline characteristics of the first 1539 German AWARE patients with H1-antihistamine-refractory CSU.

METHODS

This prospective non-interventional study included patients (18-75 years) with a diagnosis of H1-antihistamine-refractory CSU for > 2 months. Baseline demographic and disease characteristics, comorbidities, and pharmacological treatments were recorded. Quality of life (QoL) was assessed using the dermatology life quality index (DLQI), chronic urticaria QoL questionnaire (CU-Q₂ oL), and angioedema QoL questionnaire (AE-QoL, in cases of angioedema). Previous healthcare resource utilization and sick leave data were collected retrospectively.

RESULTS

Between March and December 2014, 1539 patients were assessed in 256 sites across Germany. The percentage of females, mean age, and mean body mass index were 70%, 46.3 years, and 27 kg/m² , respectively. The mean urticaria control test score was 7.9, one in two patients had angioedema, and the most frequent comorbidities were chronic inducible urticaria (CIndU; 24%), allergic rhinitis (18.2%), hypertension (18.1%), asthma (12%), and depression (9.5%). Overall, 57.6% of patients were receiving at least one pharmacological treatment including second-generation H1-antihistamines (46.3%), first-generation H1-antihistamines (9.1%), and corticosteroids (15.8%). The mean DLQI, total CU-Q₂ oL, and total AE-QoL scores were 8.3, 36.2, and 46.8, respectively. CSU patients reported frequent use of healthcare resources, including emergency services (29.7%), general practitioners (71.9%), and additional allergists or dermatologists (50.7%).

CONCLUSIONS AND CLINICAL RELEVANCE

This study reveals that German H1-antihistamine-refractory CSU patients have high rates of uncontrolled disease, angioedema, and comorbid CIndU, are undertreated, have impaired QoL, and rely heavily on healthcare resources.

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.

Standardization of double blind placebo controlled food challenge with soy within a multicentre trial

Background

Multicentre trials investigating food allergies by double blind placebo controlled food challenges (DBPCFC) need standardized procedures, challenge meals and evaluation criteria. We aimed at developing a standardized approach for identifying patients with birch related soy allergy by means of DBPCFC to soy, including determination of threshold levels, in a multicentre setting.

Methods

Microbiologically stable soy challenge meals were composed of protein isolate with consistent Gly m 4 levels. Patients sensitized to main birch allergen Bet v 1 and concomitant sensitization to its soy homologue Gly m 4 underwent DBPCFC. Outcome was defined according to presence and/or absence of ten objective signs and intensity of eight subjective symptoms as measured by visual analogue scale (VAS).

Results

138 adult subjects (63.8% female, mean age 38 years) underwent DBPCFC. Challenge meals and defined evaluation criteria showed good applicability in all centres involved. 45.7% presented with objective signs and 65.2% with subjective symptoms at soy challenge. Placebo challenge meals elicited non-cardiovascular objective signs in 11.6%. In 82 (59.4%) subjects DBPCFC was judged as positive. 70.7% of DPBCFC+ showed objective signs and 85.4% subjective symptoms at soy challenge. Subjective symptoms to soy challenge meal in DBPCFC+ subjects started at significantly lower dose levels than objective signs (p < 0.001). Median cumulative eliciting doses for first objective signs in DBPCFC+ subjects were 4.7 g [0.7–24.7] and 0.7 g [0.2–4.7] total soy protein for first subjective symptoms (p = 0.01).

Conclusions

We present the hitherto largest group of adults with Bet v 1 and Gly m 4 sensitization being investigated by DBPCFC. In this type of food allergy evaluation of DBPCFC outcome should not only include monitoring of objective signs but also scoring of subjective symptoms. Our data may contribute to standardize DBPCFC in pollen-related food allergy in multicentre settings.

Trial registration

EudraCT: 2009-011737-27.

Clinical contraindications to allergen immunotherapy: an EAACI position paper

Clinical indications for allergen immunotherapy (AIT) in respiratory and Hymenoptera venom allergy are well established; however, clinical contraindications to AIT are not always well documented. There are some discrepancies when classifying clinical contraindications for different forms of AIT as 'absolute' or 'relative'. EAACI Task Force on 'Contraindications to AIT' was created to evaluate and review current literature on clinical contraindications, and to update recommendations for both sublingual and subcutaneous AIT for respiratory and venom immunotherapy. An extensive review of the literature was performed on the use of AIT in asthma, autoimmune disorders, malignant neoplasias, cardiovascular diseases, acquired immunodeficiencies and other chronic diseases (including mental disorders), in patients treated with β-blockers, ACE inhibitors or monoamine oxidase inhibitors, in children under 5 years of age, during pregnancy and in patients with poor compliance. Each topic was addressed by the following three questions: (1) Are there any negative effects of AIT on this concomitant condition/disease? (2) Are more frequent or more severe AIT-related side-effects expected? and (3) Is AIT expected to be less efficacious? The evidence, for the evaluation of these clinical conditions as contraindications, was limited, and most of the conclusions were based on case reports. Based on an extended literature research, recommendations for each medical condition assessed are provided. The final decision on the administration of AIT should be based on individual evaluation of any medical condition and a risk/benefit assessment for each patient.

[Sting challenge: indications and execution]

BACKGROUND

Venom immunotherapy (VIT) is a highly effective treatment for Hymenoptera venom allergy. However, VIT treatment may fail to protect against systemic reactions. Many in vitro parameters as well as skin test reactivity change during the course of VIT; however, similar to the pre-treatment situation, there is no in vitro parameter, which reliably indicates the clinical reactivity of a sensitized patient. Sting challenge with the culprit insect is the only tool which reveals clinical reactivity.

OBJECTIVES

To define the indications, contraindications and performance of sting challenge tests.

MATERIAL AND METHODS

Review of the literature.

RESULTS

Sting challenge tests are not recommended for individuals who are not being treated with VIT, and are also not recommended as a routine diagnostic method for patients who have stopped VIT. Indications of sting challenge are identification of patients who are not protected, and quality of life issues. Major contraindications of sting challenge are repeated side effects or a field sting reaction during maintenance VIT, and unstable medical disease. Risk factors for treatment failure are mastocytosis, bee venom allergy, repeated side effects of VIT, and ACE inhibitors. Protection rate is significantly better in patients who are treated with elevated venom dose, with double VIT, and longer treatment duration.

CONCLUSIONS

For the majority of patients quality of life will significantly improve after tolerated sting challenge. A sting challenge test is particularly important in those patients who are at increased risk due their increased risk of treatment failure. If in patients with risk factors for treatment failure, VIT is done with elevated dose or if no risk factors are present, a sting challenge may not be needed. VIT with an elevated dose may prevent or correct treatment failure.

Occupational anaphylaxis--an EAACI task force consensus statement

Anaphylaxis is a systemic allergic reaction, potentially life-threatening that can be due to nonoccupational or, less commonly, to occupational triggers. Occupational anaphylaxis (OcAn) could be defined as anaphylaxis arising out of triggers and conditions attributable to a particular work environment. Hymenoptera stings and natural rubber latex are the commonest triggers of OcAn. Other triggers include food, medications, insect/mammal/snake bites, and chemicals. The underlying mechanisms of anaphylactic reactions due to occupational exposure are usually IgE-mediated and less frequently non-IgE-mediated allergy or nonallergic. Some aspects of work-related allergen exposure, such as route and frequency of exposure, type of allergens, and cofactors may explain the variability of symptoms in contrast to the nonoccupational setting. When assessing OcAn, both confirmation of the diagnosis of anaphylactic reaction and identification of the trigger are required. Prevention of further episodes is important and is based on removal from further exposure. Workers with a history of OcAn should immediately be provided with a written emergency management plan and an adrenaline auto-injector and educated to its use. Immunotherapy is recommended only for OcAn due to Hymenoptera stings.

Anaphylaxis: guidelines from the European Academy of Allergy and Clinical Immunology

Anaphylaxis is a clinical emergency, and all healthcare professionals should be familiar with its recognition and acute and ongoing management. These guidelines have been prepared by the European Academy of Allergy and Clinical Immunology (EAACI) Taskforce on Anaphylaxis. They aim to provide evidence-based recommendations for the recognition, risk factor assessment, and the management of patients who are at risk of, are experiencing, or have experienced anaphylaxis. While the primary audience is allergists, these guidelines are also relevant to all other healthcare professionals. The development of these guidelines has been underpinned by two systematic reviews of the literature, both on the epidemiology and on clinical management of anaphylaxis. Anaphylaxis is a potentially life-threatening condition whose clinical diagnosis is based on recognition of a constellation of presenting features. First-line treatment for anaphylaxis is intramuscular adrenaline. Useful second-line interventions may include removing the trigger where possible, calling for help, correct positioning of the patient, high-flow oxygen, intravenous fluids, inhaled short-acting bronchodilators, and nebulized adrenaline. Discharge arrangements should involve an assessment of the risk of further reactions, a management plan with an anaphylaxis emergency action plan, and, where appropriate, prescribing an adrenaline auto-injector. If an adrenaline auto-injector is prescribed, education on when and how to use the device should be provided. Specialist follow-up is essential to investigate possible triggers, to perform a comprehensive risk assessment, and to prevent future episodes by developing personalized risk reduction strategies including, where possible, commencing allergen immunotherapy. Training for the patient and all caregivers is essential. There are still many gaps in the evidence base for anaphylaxis.

Symptom profile and risk factors of anaphylaxis in Central Europe

BACKGROUND

Anaphylaxis is the most severe manifestation of an IgE-dependent allergy. Standardized acquired clinical data from large cohorts of well-defined cases are not available. The aim of this study was to analyse the symptom profile and risk factors of anaphylaxis in a large Central European cohort.

METHODS

We acquired data from patients in Germany, Austria and Switzerland who experienced a severe allergic reaction defined by the onset of severe pulmonary and/or severe cardiovascular symptoms. The data were gained via an online questionnaire from 83 medical centres specialized in allergy. Data were collected from 2006 to 2010 and analysed by using a multinomial regression model.

RESULTS

A total of 2012 paediatric and adult patients were included into the present analysis. The skin (84%) was the most frequently affected organ followed by the cardiovascular (72%) and the respiratory (68%) system. The regression model analysing the onset of cardiovascular versus respiratory symptoms revealed a strong impact of age (adjusted OR = 6.08; 95% CI, 3.35-11.01; P < 0.001). Furthermore, the elicitor food (adjusted OR = 0.29; 95% CI, 0.21-0.41, P < 0.001) and the presence of atopic diseases (adjusted OR = 0.54; 95% CI, 0.40-0.73, P < 0.001) were significantly associated with the onset of respiratory symptoms.

CONCLUSION

Data from individuals who experienced anaphylaxis can support the identification of risk factors. The present study indicates that age, the elicitor itself and the presence of atopic diseases have an impact on the symptom profile of anaphylaxis. Identifying further risk factors of anaphylaxis is of significant importance for clinical practice in the future.

IgE-mediated hypersensitivity reactions to cannabis in laboratory personnel

BACKGROUND

There have been sporadic reports of hypersensitivity reactions to plants of the Cannabinaceae family (hemp and hops), but it has remained unclear whether these reactions are immunologic or nonimmunologic in nature.

OBJECTIVE

We examined the IgE-binding and histamine-releasing properties of hashish and marijuana extracts by CAP-FEIA and a basophil histamine release test.

METHODS

Two workers at a forensic laboratory suffered from nasal congestion, rhinitis, sneezing and asthmatic symptoms upon occupational contact with hashish or marijuana, which they had handled frequently for 25 and 16 years, respectively. Neither patient had a history of atopic disease. Serum was analyzed for specific IgE antibodies to hashish or marijuana extract by research prototype ImmunoCAP, and histamine release from basophils upon exposure to hashish or marijuana extracts was assessed. Results were matched to those of 4 nonatopic and 10 atopic control subjects with no known history of recreational or occupational exposure to marijuana or hashish.

RESULTS

Patient 1 had specific IgE to both hashish and marijuana (CAP class 2), and patient 2 to marijuana only (CAP class 2). Controls proved negative for specific IgE except for 2 atopic individuals with CAP class 1 to marijuana and 1 other atopic individual with CAP class 1 to hashish. Stimulation of basophils with hashish or marijuana extracts elicited histamine release from basophils of both patients and 4 atopic control subjects.

CONCLUSIONS

Our results suggest an IgE-related pathomechanism for hypersensitivity reactions to marijuana or hashish.

[Skin tests for diagnostics of allergic immediate-type reactions. Guideline of the German Society for Allergology and Clinical Immunology]

Skin tests in patients with IgE-mediated immediate type allergy are performed with the intention to establish a contact between allergens and skin mast cells. The latter carry specific IgE antibodies on their surface. If mast cells get activated, mediators (mainly histamine) are released which induce a visible skin reaction (wheal and erythema).[nl]Skin tests are indicated, if an immediate type allergic disease is suspected. Systemic anaphylactic reactions at skin testing are very rare. However, it is necessary to take them into account and to provide emergency treatment. Relative contraindications comprise skin diseases in the test area, poor general condition and insufficiently treated severe asthma. If tests are used, which have a higher risk for a systemic anaphylactic reaction, pregnancy or beta-blocker therapy, are further contraindications.[nl]Skin test application does not depend on patient age. However, in pre-school age tests are reluctantly performed. It is essential to consider the half-life of drugs which may interfere with the test result, and which have to be discontinued early enough before testing. After anaphylactic reactions there may be a refractory period. Therefore, tests should not be done within the first week after such reactions. Skin prick tests are the procedures of first choice, intradermal tests are more sensitive than prick tests. Skin tests are performed at the flexor side of the forearm. As intradermal tests are more inconvenient, testing can be also done at a less susceptible site of the body (upper back).[nl]It is recommended to use standardized test extracts. However, if standardised extracts are not available or do not yield suitable test results, one may switch to other preparations. If the patient shows a positive reaction to a non-standardized substance, control tests should be performed in healthy subjects in order to exclude an unspecific reaction.[nl]The reaction is read after 15 to 20 min. Skin tests are regarded positive if the mean wheal diameter is ≥ 3 mm at the prick test, and ≥ 5 mm at the intradermal test.[nl]Skin test results may be negative although patients are allergic. If a skin test is positive, one will have to distinguish reactions, which are clinically relevant, from those, which are not. History and/or challenge tests help to clarify the relevance of a sensitization. Usually, a clinically irrelevant sensitization does not lead to practical consequences.

Serum concentration of baseline mast cell tryptase: evidence for a decline during long-term immunotherapy for Hymenoptera venom allergy

BACKGROUND

Baseline serum mast cell tryptase concentration (BTC) is thought to reflect the constitutive mast cell load or activity of an individual patient. Little is known about the individual stability of BTC during long-term venom immunotherapy (VIT).

OBJECTIVE

To investigate the intra-individual stability of BTC over time in patients with Hymenoptera venom allergy.

METHODS

Three hundred and two patients were studied. BTC was measured before and at least twice during VIT. At least 4 weeks lay between BTC measurements and the most recent field sting, in-hospital sting, or preceding venom injection. Multifactorial mixed linear models were used to analyse BTC changes over time.

RESULTS

Median observation time was 4.2 years (range 2-12 years). Before VIT, the median BTC was 6.8 microg/L (range 1.14-177 microg/L). The median coefficient of variation (CV) over time was 15.3% (range 1.9-63.8%). The median CV was significantly smaller in patients presenting with an elevated BTC (>11.4 microg/L) than in patients with a normal BTC (11.4%, range 2.6-39.5%; vs. 17.6%, range 1.9- 63.8%; P<0.001). During VIT and after adjusting for age and gender, we found a slight but significant decrease of BTC over time (2.5% per year, 95% confidence interval 2.0-3.0%, P<0.001).

CONCLUSION

Individual variation of BTC during VIT does not rise when BTC is increased before therapy. VIT is associated with a small, but continuous decrease of BTC over time possibly indicating a dampened mast cell function or a decline in mast cell burden.

[Venom immunotherapy. Side effects and efficacy of treatment]

Venom immunotherapy (VIT) protects patients with Hymenoptera venom anaphylaxis from subsequent potentially life-threatening reactions. The most important side effect are systemic anaphylactic reactions (SAR). Compared to the administration of aqueous extracts according to a rush protocol, the frequency of systemic and also local side effects will be lower if depot extracts are used and a slow conventional dose schedule is used, as compared to rush desensitization with aqueous extracts. However, protection often has to be achieved rapidly, and adequate surveillance of sufficient duration is hardly feasible in outpatients. Therefore, VIT according to rush schedules in inpatients remains indispensable. Pre-treatment with H(1)-blocking antihistamines reduces frequency and intensity of local and mild systemic adverse reactions during VIT. Up to 25% of patients again develop a SAR when re-stung while on VIT with the usual maintenance dose of 100 microg venom. Patients with honeybee venom allergy or with mastocytosis are at a higher risk for treatment failure. Almost all of them will become fully protected by increasing the maintenance dose, 200 microg venom being sufficient in most cases. Patients with significant risk factors may be treated from the beginning with an elevated maintenance dose, particularly when they are allergic to honeybee venom.

Possible circadian variation of serum mast cell tryptase concentration

BACKGROUND

A temporarily elevated level of serum mast cell tryptase (ST) indicates mast cell activation and occurs in systemic anaphylactic reactions (SAR). We measured ST following a sting challenge in vespid venom-allergic patients treated with venom immunotherapy (VIT) and in healthy controls, respectively.

AIM OF THE STUDY

To assess changes of ST over time in vespid venom-allergic patients at the occasion of a re-sting and in healthy controls.

METHODS

A sting challenge was performed in 20 patients on vespid VIT to monitor efficacy of VIT. ST was measured between 9.00 and 10.00 a.m. (baseline). Sting challenge was performed at 2.00 p.m., and ST was determined again 20 min, 90 min and 18 h later. Measurements at corresponding times of the day were done in nine healthy controls.

RESULTS

One patient developed a mild SAR to the sting challenge which was associated with a temporary increase of ST. In the other 19 patients who tolerated the sting challenge without SAR ST decreased significantly by 18.0% (median, range 8.3-36.7%). Twenty minutes after the sting when compared with baseline levels (P < 0.001), a significant decrease of ST was still present after 90 min (median 13.7%) (P < 0.001), but not after 18 h (P = 0.57). A comparably significant temporary decline was found in controls.

CONCLUSIONS

The temporary decline of ST in patients and in controls suggests a circadian variation of ST concentration. A normal diurnal pattern of ST concentration after sting challenge is associated with successful treatment.

[Emergencies in allergology]

The clinical presentation of allergological emergencies is heterogeneous. The most important conditions are anaphylaxis (which is frequent) and Stevens-Johnson syndrome or toxic epidermal necrolysis (which are rare). In the acute phase it is most important to recognize the exogenous elicitation of the condition as soon as possible, otherwise severe sequelae, even death of the patient, may occur. Management is based on immediate elimination of possible causative agents and symptomatic therapeutic measures. Furthermore, allergological diagnostics are necessary without delay to identify what has elicited the reaction. This information makes possible long-term treatment in order to avoid further hypersensitivity reactions.

Specific immunotherapy in honeybee venom allergy: a comparative study using aqueous and aluminium hydroxide adsorbed preparations

BACKGROUND

For the immunotherapy of Hymenoptera venom allergy various preparations and treatment protocols are in use. However, controlled studies making direct comparisons of the efficacy and safety of different regimens are rare.

OBJECTIVE

To assess prospectively different venom immunotherapy (VIT) protocols using an aqueous or an aluminium hydroxide adsorbed allergen preparation for the treatment of honeybee venom (HBV) allergy.

METHODS

Sixty-five HBV allergic patients (42 males, 23 females; aged 17-75 years) with a history of systemic anaphylactic reactions (SARs) to honeybee stings were treated according to three different regimens. During the incremental phase, patients in group A (n = 21) or B (n = 21) received an aqueous preparation according to a rush protocol. Patients in group C (n = 23) were treated with conventional ("slow") VIT using an aluminium hydroxide adsorbed depot preparation. The maintenance dose was 100 microg venom in all groups. Maintenance treatment in group A was performed with the aqueous preparation administered every 4 weeks, whereas in groups B and C the depot preparation was administered every 8 weeks (group B) or every 4 weeks (group C). A sting challenge test with a living honeybee was performed in 49 patients, 6-12 months after reaching the maintenance dose. Another seven patients were stung accidentally by a honeybee ("field sting").

RESULTS

Treatment with the aqueous preparation evoked large local reactions more frequently than the depot preparation in the dose increase phase [53/693 (7.6%) vs 8/206 (3.9%); P = 0.059] and also in the course of maintenance therapy [85/172 (49.4%) vs 58/478 (12.1%); P < 0.001]. During the dose increase phase, systemic side-effects seemed to occur more frequently in patients on rush VIT with the aqueous preparation compared to patients initially treated with the conventional schedule using the depot preparation [13/42 (31.0%) vs 3/23 (13.0%); not significant). When re-stung by the culprit insect, SARs were observed in 3/20 patients (15.0%) in group A, 2/18 (11.1%) in group B and 3/18 (16.7%) in group C (not significant).

CONCLUSIONS

The aluminium hydroxide adsorbed HBV preparation caused fewer large local reactions than the aqueous preparation. The therapeutic efficacy of the three treatment protocols did not differ.

Patients still reacting to a sting challenge while receiving conventional Hymenoptera venom immunotherapy are protected by increased venom doses

BACKGROUND

Up to 20% of patients allergic to Hymenoptera venom are not protected by conventional venom immunotherapy (VIT) with 100 microg of any single venom.

OBJECTIVE

We sought to evaluate the efficacy of an increased venom dose in patients allergic to Hymenoptera venom still reacting systemically to a sting challenge despite immunotherapy with 100 microg of venom every 4 weeks.

METHODS

In this retrospective study patients were included who still had reacted systemically to a sting challenge with a living bee or wasp despite VIT with a maintenance dose of 100 microg every 4 weeks. The maintenance dose was increased to 150 or 200 microg every 4 weeks, and a second sting challenge was performed. If a patient reacted again, the dose was further increased. Baseline mast-cell tryptase levels were assessed by using a fluoroenzyme immunoassay in stored patient sera.

RESULTS

While receiving a maintenance dose of 100 microg of venom every 4 weeks for 7 to 38 months, 18 patients reacted systemically to a bee sting and 22 reacted to a wasp sting. After an increase of the maintenance dose to 150 microg, 2 of 4 patients allergic to bee venom (BV) and 6 of 6 patients allergic to yellow jacket venom (YJV) no longer reacted systemically to the sting challenge. The respective rates of full protection were 13 of 14 and 15 of 16 in patients with an increase of the maintenance dose to 200 microg from the start. Of those 4 individuals not protected by the first dose increase, one patient allergic to BV (prior dose of 150 microg) and one patient allergic to YJV (prior dose of 200 microg) did not react systemically to a further sting challenge while receiving 200 microg of BV or 250 microg of YJV, respectively. One patient allergic to BV who had a systemic reaction to the sting challenge while receiving 150 microg was not protected after a dose increase to 200 microg; she later received a dose of 400 microg of BV, and no further sting challenge was performed. The patient allergic to BV who still reacted systemically after a first dose increase to 200 microg was a female patient with urticaria pigmentosa. She had repeated systemic adverse reactions to further BV immunotherapy, necessitating discontinuation of the treatment; however, she tolerated well VIT with 200 microg of YJV. In all other patients, no unusual adverse reactions to the increased venom doses were observed. Baseline serum tryptase levels were elevated above 13.5 microg/L (95th percentile in normal subjects) in 9 (28.1%) of 32 patients.

CONCLUSIONS

The majority of patients allergic to Hymenoptera venom who still reacted systemically to a sting challenge despite VIT with a dose of 100 microg every 4 weeks can be fully protected by an increased maintenance dose. This dose increase is well tolerated by most patients. The rather high proportion of patients with elevated baseline serum tryptase levels necessitates further investigation of a possible association between mastocytosis and treatment failure of conventionally dosed VIT.

[Anaphylactic reaction to Ficus benjamina (weeping fig)]

Ficus benjamina (weeping fig) is a widespread indoor ornamental plant. Allergens of Ficus benjamina are a well-known cause of IgE-mediated respiratory diseases. We treated a 32-year-old female who for 10 years had suffered from perennial rhinoconjunctivitis. When dusting her 2 meter high Ficus benjamina, she developed an anaphylactic reaction which resolved without sequelae. Skin prick testing revealed a strong immediate type reaction to a Ficus extract, the serum concentration of specific IgE-antibodies to Ficus was > 100 kU/I (CAP class 6). In view of these strong test reactions and the conclusive history, no challenge tests with Ficus allergens were performed. After removal of the Ficus plants which she had owned for 17 years and after thorough cleaning of her dwelling, the patient's symptoms of perennial rhinoconjunctivitis stopped. The patient also was sensitized to, but not allergic to natural rubber latex, which occurs frequently in Ficus allergy and probably is due to cross reactivity to allergens from both sources. As Ficus benjamina is an important source of indoor allergens, it should not be used in dwellings or work places.

Frequency of natural rubber latex allergy in adults is increased after multiple operative procedures

BACKGROUND

It has been shown that immediate-type allergy to natural rubber latex (NRL) affects predominantly health-care workers and infants with malformations requiring repeated medical procedures. Adult patients with multiple invasive procedures are not thought to be at an increased risk of NRL allergy.

METHODS

A total of 325 consecutive adult inpatients (54.4+/-15.6 years; 219 men, 106 women) awaiting surgical or urologic procedures were assessed by questionnaire-based history (atopic diseases, number of previous standard operative or endoscopic procedures, intolerance to rubber products, and adverse reactions during medical care), by skin prick tests with different NRL test solutions, by measurement of NRL-specific IgE in the serum, and, if sensitization to NRL was found, by cutaneous challenge tests with NRL-containing material. Subjects were classified as sensitized to NRL if skin prick test reactions to NRL were positive or if NRL-specific IgE antibodies were found. NRL allergy was defined as NRL sensitization and immediate-type symptoms to NRL.

RESULTS

Thirty-one of 325 (9.5%) subjects were found to be sensitized to NRL, 14/285 (4.9%) by skin prick testing and 23/323 (7.1%) by NRL-specific IgE antibodies in the serum. Four individuals (1.2%) were diagnosed as having clinically manifest NRL allergy, and another 27 (8.3%) were sensitized to NRL without symptoms to date. The frequency of previous invasive procedures was zero in eight patients, up to 10 in 245, 11-20 in 52, 21-30 in seven, and over 30 (up to 83) in 13 patients. No association was found between the number of invasive procedures and NRL sensitization without clinical symptoms. However, 3/4 patients with NRL allergy had undergone more than 30 interventions, and 1/4 had had 11 operations. Frequent invasive procedures (more than 10) were significantly associated with NRL allergy (P<0.001). Allergy or sensitization to NRL was associated with atopy (21/31 vs 87/294) (P<0.001).

CONCLUSIONS

A remarkable percentage of unselected adult patients undergoing surgical procedures have allergy or sensitization to NRL. Repeated invasive treatment appears to be a risk factor for NRL allergy.