Risk factors for fatal and nonfatal reactions to immunotherapy (2008-2018): postinjection monitoring and severe asthma

Allergen Immunotherapy: The Evidence Supporting the Efficacy and Safety of Subcutaneous Immunotherapy and Sublingual Forms of Immunotherapy for Allergic Rhinitis/Conjunctivitis and Asthma

Allergen immunotherapy (AIT) is a recognized key therapeutic modality for the treatment of allergic respiratory disease. Definitive studies have provided evidence-based data to demonstrate its effectiveness in allergic rhinitis and asthma due to the inhalation of proteinaceous allergic substances from specific seasonal pollens, dust mites, animal allergens, and certain mold spores. Over the ensuing decades, laboratory investigations have provided objective evidence to demonstrate immunologic changes, including production of protective IgG antibody, suppression of IgE antibody, upregulation of regulatory T cells, and induction of a state of immune tolerance to the offending allergen(s). Tangential to this work were carefully designed clinical studies that defined allergen dose and duration of treatment, established the importance of preparing extracts with standardized allergens (or well-defined extracts) based on major protein moieties, and used allergen provocation models to demonstrate efficacy superior to placebo. In the United States, the use of subcutaneous immunotherapy extracts for AIT was grandfathered in by the Food and Drug Administration based on expert literature review. In contrast, sublingual tablet immunotherapy underwent formal clinical development programs (phase I-III clinical trials) that provided the necessary clinical evidence for safety and efficacy that led to regulatory agency approvals for the treatment of allergic rhinitis in properly characterized patients with allergy. The allergy specialist's treatment options currently include traditional subcutaneous AIT and specific sublingual tablets approved for grass, ragweed, house dust mites, trees belonging to the birch-homologous group, and Japanese cedar. Tangential to this are sublingual drops that are increasingly being used off-label (albeit not approved by the Food and Drug Administration) in the United States. This article will review the evidence-based literature supporting the use of these forms of AIT, as well as focus on several current controversies and gaps in our knowledge base that have relevance for the appropriate selection of patients for treatment with specific AIT.

Anaphylaxis in a Swiss university emergency department: clinical characteristics and supposed triggers

BACKGROUND

Anaphylaxis is the most severe form of acute systemic and potentially life-threatening reactions triggered by mast and basophilic cells. Recent studies show a worldwide incidence between 50 and 112 occurrences per 100,000 person-years. The most identified triggers are food, medications, and insect venoms. We aimed to analyze triggers and clinical symptoms of patients presenting to a Swiss university emergency department for adults.

METHODS

Six-year retrospective analysis (01/2013 to 12/2018) of all patients (> 16 years of age) admitted with moderate or severe anaphylaxis (classification of Ring and Messmer ≥ 2) to the emergency department. Patient and clinical data were extracted from the electronic medical database of the emergency department.

RESULTS

Of the 531 includes patients, 53.3% were female, the median age was 38 [IQR 26-51] years. The most common suspected triggers were medications (31.8%), food (25.6%), and insect stings (17.1%). Organ manifestations varied among the different suspected triggers: for medications, 90.5% of the patients had skin symptoms, followed by respiratory (62.7%), cardiovascular (44.4%) and gastrointestinal symptoms (33.7%); for food, gastrointestinal symptoms (39.7%) were more frequent than cardiovascular symptoms (36.8%) and for insect stings cardiovascular symptoms were apparent in 63.8% of the cases.

CONCLUSIONS

Average annual incidence of moderate to severe anaphylaxis during the 6-year period in subjects > 16 years of age was 10.67 per 100,000 inhabitants. Medications (antibiotics, NSAID and radiocontrast agents) were the most frequently suspected triggers. Anaphylaxis due to insect stings was more frequently than in other studies. Regarding clinical symptoms, gastrointestinal symptoms need to be better considered, especially that initial treatment with epinephrine is not delayed.

Safety of subcutaneous immunotherapy with Novo-Helisen-Depot in the children: a retrospective analysis from a single center in Northern China

Background

Little is known about the safety of mite extract product Novo-Helisen Depot (NHD) as subcutaneous immunotherapy (SCIT) in the children with mite allergy especially immediate/late local reaction (LRs).

Methods

We conducted a retrospective study analyzing the adverse events of the children undergoing subcutaneous immunotherapy with NHD. Adverse events included local and systemic adverse reactions (SRs) at the very early and late stage. The correlation of the basic characteristics, laboratory analysis results, LRs and SRs were analyzed.

Results

Two hundred and eighty-seven patients received at least 15 months of subcutaneous immunotherapy with NHD were included in the analysis. Skin-prick testing (SPT) results of D. pteronyssinus was associated with an increased risk of immediate LRs in build-up phase (OR = 1.53, 95% CI: 1.02, 2.37) and delayed LRs in maintenance phase (OR = 1.58, 95% CI: 1.05, 2.46), while SPT results of D. farinae was associated with an increased risk of SRs (OR = 3.22, 95% CI: 1.17, 10.00) and severe SRs (OR = 7.68, 95% CI: 1.13, 109.50). Serum IgE level of D. pteronyssinus was associated with an increased risk of SRs (OR = 1.01, 95% CI: 1.00, 1.03). Patients with both asthma and allergic rhinitis was associated with an increased risk of SR, and severe SRs (P < 0.05).

Conclusion

NHD as SCIT is safe. The children with higher SPT level with D. farinae or D. pteronyssinus, higher serum IgE level of D. pteronyssinus, children with both asthma and allergic rhinitis, and the children with treatment interruption had higher risk of adverse events.

Clinical Practice Guideline: Immunotherapy for Inhalant Allergy

OBJECTIVE

Allergen immunotherapy (AIT) is the therapeutic exposure to an allergen or allergens selected by clinical assessment and allergy testing to decrease allergic symptoms and induce immunologic tolerance. Inhalant AIT is administered to millions of patients for allergic rhinitis (AR) and allergic asthma (AA) and is most commonly delivered as subcutaneous immunotherapy (SCIT) or sublingual immunotherapy (SLIT). Despite its widespread use, there is variability in the initiation and delivery of safe and effective immunotherapy, and there are opportunities for evidence-based recommendations for improved patient care.

PURPOSE

The purpose of this clinical practice guideline (CPG) is to identify quality improvement opportunities and provide clinicians trustworthy, evidence-based recommendations regarding the management of inhaled allergies with immunotherapy. Specific goals of the guideline are to optimize patient care, promote safe and effective therapy, reduce unjustified variations in care, and reduce the risk of harm. The target patients for the guideline are any individuals aged 5 years and older with AR, with or without AA, who are either candidates for immunotherapy or treated with immunotherapy for their inhalant allergies. The target audience is all clinicians involved in the administration of immunotherapy. This guideline is intended to focus on evidence-based quality improvement opportunities judged most important by the guideline development group (GDG). It is not intended to be a comprehensive, general guide regarding the management of inhaled allergies with immunotherapy. The statements in this guideline are not intended to limit or restrict care provided by clinicians based on their experience and assessment of individual patients.

ACTION STATEMENTS

The GDG made a strong recommendation that (Key Action Statement [KAS] 10) the clinician performing allergy skin testing or administering AIT must be able to diagnose and manage anaphylaxis. The GDG made recommendations for the following KASs: (KAS 1) Clinicians should offer or refer to a clinician who can offer immunotherapy for patients with AR with or without AA if their patients' symptoms are inadequately controlled with medical therapy, allergen avoidance, or both, or have a preference for immunomodulation. (KAS 2A) Clinicians should not initiate AIT for patients who are pregnant, have uncontrolled asthma, or are unable to tolerate injectable epinephrine. (KAS 3) Clinicians should evaluate the patient or refer the patient to a clinician who can evaluate for signs and symptoms of asthma before initiating AIT and for signs and symptoms of uncontrolled asthma before administering subsequent AIT. (KAS 4) Clinicians should educate patients who are immunotherapy candidates regarding the differences between SCIT and SLIT (aqueous and tablet) including risks, benefits, convenience, and costs. (KAS 5) Clinicians should educate patients about the potential benefits of AIT in (1) preventing new allergen sensitizations, (2) reducing the risk of developing AA, and (3) altering the natural history of the disease with continued benefit after discontinuation of therapy. (KAS 6) Clinicians who administer SLIT to patients with seasonal AR should offer pre- and co-seasonal immunotherapy. (KAS 7) Clinicians prescribing AIT should limit treatment to only those clinically relevant allergens that correlate with the patient's history and are confirmed by testing. (KAS 9) Clinicians administering AIT should continue escalation or maintenance dosing when patients have local reactions (LRs) to AIT. (KAS 11) Clinicians should avoid repeat allergy testing as an assessment of the efficacy of ongoing AIT unless there is a change in environmental exposures or a loss of control of symptoms. (KAS 12) For patients who are experiencing symptomatic control from AIT, clinicians should treat for a minimum duration of 3 years, with ongoing treatment duration based on patient response to treatment. The GDG offered the following KASs as options: (KAS 2B) Clinicians may choose not to initiate AIT for patients who use concomitant beta-blockers, have a history of anaphylaxis, have systemic immunosuppression, or have eosinophilic esophagitis (SLIT only). (KAS 8) Clinicians may treat polysensitized patients with a limited number of allergens.

Plain Language Summary: Immunotherapy for Inhalant Allergy

The plain language summary explains allergen immunotherapy to patients, families, and caregivers. The summary is for patients aged 5 years and older who are experiencing symptoms from inhalant allergies and are considering immunotherapy as a treatment option. It is based on the 2024 "Clinical Practice Guideline: Immunotherapy for Inhalant Allergy." This plain language summary is a companion publication to the full guideline, which provides greater detail for health care providers. Guidelines and their recommendations may not apply to every patient, but they can be used to find best practices and quality improvement opportunities.

The Art of Immunotherapy

Selection of a patient with rhinitis/conjunctivitis or asthma for allergy immunotherapy (AIT) requires several decisions. First, does the patient's sensitization, pattern of exposure to an allergen, and degree of exposure to that allergen reasonably suggest a causal relationship? Does the level and duration of symptoms warrant the cost and inconvenience of immunotherapy, or is the patient motivated by the disease-modifying potential of AIT? If AIT is selected, is the choice to be greater safety and convenience with sublingual immunotherapy (SLIT) tablets, but with treatment probably limited to 2 or 3 allergens, or for subcutaneous immunotherapy where multiple allergen therapy is the rule and efficacy may be somewhat greater, at least initially, or does the physician go off-label into the unknowns of liquid SLIT? Are there extracts of sufficient potency to achieve likely effective doses? How does the physician deal with large local or systemic reactions, with gaps in treatment, with pollen seasons, and the use of premedication or cautionary prescription of epinephrine autoinjectors? How can adherence to AIT be improved? These and other questions are addressed in this paper.

Safety of allergen immunotherapy in children

PURPOSE OF REVIEW

The current review discusses allergen immunotherapy (AIT) safety in children.

RECENT FINDINGS

AIT is a well tolerated and effective treatment for pediatric allergic conditions. While mostly well tolerated, severe reactions and near fatal reactions may occur with subcutaneous immunotherapy (SCIT) once in every 160 000 visits. Sublingual immunotherapy (SLIT) is associated more with local side effects, but severe systemic reactions, including anaphylaxis, have been rarely reported. Providing informed consent, recognizing risk factors for severe systemic reactions, such as severe or uncontrolled asthma, and mitigating the risk of severe reactions are important components to improving the safety of AIT.

SUMMARY

Overall, AIT is well tolerated in children, and data suggest that the incidence of systemic reactions in children receiving SCIT is no less than mixed populations of adult and pediatric patients. SLIT carries less risk for systemic reactions, and local oral site-application reactions are usually mild and resolve within 15 days of treatment.

Efficacy and safety of subcutaneous immunotherapy in asthmatic children allergic to house dust mite: a meta-analysis and systematic review

Background

Subcutaneous immunotherapy (SCIT) has been proved to be effective and safe in adult asthma. But it is still controversial in children.

Object

To evaluate the efficacy and safety of SCIT in asthmatic children with allergy to house dust mite.

Method

We searched the databases of Cochrane Library, EMBASE and MEDLINE (from 1 January 1990 to 1 December 2022). Two reviewers independently screened studies, extracted data and critically appraised the risk of bias. We used the Revman 5 to synthesize the effect sizes.

Results

We finally selected 38 eligible studies including 21 randomized controlled trials to evaluate the efficacy and safety of SCIT and 17 observational studies to assess the safety. The results revealed that short-term asthma symptom scores were declined with a standardized mean difference (SMD) of -1.19 (95% CI: -1.87, -0.50) in 12 researches with high heterogeneity. Short-term asthma medication scores were decreased with SMD -1.04 (95% CI: -1.54, -0.54) in 12 heterogeneous researches. One study showed no significant reduction in combined symptom and medication scores without providing details. No studies we reviewed reported long-term efficacy. SCIT resulted in an obviously increased risk of adverse reactions compared with placebo. For secondary outcomes, SCIT improved life quality and reduced the numbers of annual asthma attacks and allergen-specific airway hyperreactivity, but without significant improvement in pulmonary function, asthma control or hospitalization.

Conclusions

SCIT can reduce the short-term symptom scores and medication scores regardless of different treatment duration or mono/polysensitization, but with an increased incidence of local and systemic adverse effects. Further studies on pediatric asthma are needed to evaluate the long-term efficacy, and clarify the effectiveness of SCIT in specific population using mix allergen extracts or with severe asthma. Overall, it is recommended for children with mild-moderate HDM-driven allergic asthma.

Evaluation of Safety, Efficacy, and Compliance of Intralymphatic Immunotherapy for Allergic Rhinoconjunctivitis: A Systematic Review and Meta-Analysis

INTRODUCTION

Intralymphatic immunotherapy (ILIT) is an emerging type of allergen immunotherapy with fewer injections and shorter course for allergic rhinoconjunctivitis (ARC). The efficacy and safety have not been confirmed by informative and powerful evidence yet.

METHODS

A systematic review and meta-analysis were conducted through electronic searching with PubMed, Web of Science, Embase, Scopus, and China National Knowledge Infrastructure (CNKI). The safety (incidence of adverse events [AEs]), compliance (percent of patients completing treatment), and clinical efficacy of ILIT were evaluated. Clinical efficacy could be assessed by improvement of subjective symptom and rescue medication use or the nasal tolerance to specific allergen. This study is registered with PROSPERO (CRD42022353562).

RESULTS

12 randomized controlled trials (RCTs) comparing ILIT with placebo and 3 trials (2 RCTs and one case-control study) comparing ILIT and SCIT were included in this review. Totally, 582 patients diagnosed as AR or ARC were enrolled. Almost all the AEs were mild-to-moderate reactions except 2 patients developed anaphylactic reactions at the intralymphatic injection dose 5,000 SQ-U in one study. ILIT got higher incidence of local AEs than placebo, but their incidence of systemic AEs was similar. ILIT was safer than SCIT (p < 0.05). Almost all the patients could complete ILIT treatment, and the most common reason for discontinuation of ILIT was AEs. The compliance of patients receiving ILIT seemed higher than patients receiving SCIT. ILIT could significantly ameliorate subjective allergic symptoms, especially for seasonal ARC, and increase nasal tolerance, similar to SCIT.

CONCLUSION

ILIT was a safe and effective treatment for ARC and could achieve comparable clinical improvement with SCIT with shorter duration and higher compliance. Moreover, ILIT was safer than SCIT.

International consensus statement on allergy and rhinology: Allergic rhinitis - 2023

BACKGROUND

In the 5 years that have passed since the publication of the 2018 International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis (ICAR-Allergic Rhinitis 2018), the literature has expanded substantially. The ICAR-Allergic Rhinitis 2023 update presents 144 individual topics on allergic rhinitis (AR), expanded by over 40 topics from the 2018 document. Originally presented topics from 2018 have also been reviewed and updated. The executive summary highlights key evidence-based findings and recommendation from the full document.

METHODS

ICAR-Allergic Rhinitis 2023 employed established evidence-based review with recommendation (EBRR) methodology to individually evaluate each topic. Stepwise iterative peer review and consensus was performed for each topic. The final document was then collated and includes the results of this work.

RESULTS

ICAR-Allergic Rhinitis 2023 includes 10 major content areas and 144 individual topics related to AR. For a substantial proportion of topics included, an aggregate grade of evidence is presented, which is determined by collating the levels of evidence for each available study identified in the literature. For topics in which a diagnostic or therapeutic intervention is considered, a recommendation summary is presented, which considers the aggregate grade of evidence, benefit, harm, and cost.

CONCLUSION

The ICAR-Allergic Rhinitis 2023 update provides a comprehensive evaluation of AR and the currently available evidence. It is this evidence that contributes to our current knowledge base and recommendations for patient evaluation and treatment.

Risk of anaphylaxis in cluster vs standard subcutaneous multiallergen immunotherapy

BACKGROUND

Cluster schedules for subcutaneous allergen immunotherapy (AIT) require significantly fewer injections, but there have been conflicting reports regarding the risk of systemic reactions (SR).

OBJECTIVE

To compare the incidence of SRs during the build-up stages of multiallergen standard vs cluster immunotherapy.

METHODS

Data on SRs were collected prospectively from 91 urban adult patients who underwent either standard or cluster AIT at the Johns Hopkins Allergy and Asthma Center from 2014 to 2022. The SRs were recorded during the build-up phase and compared for both protocols using Pearson's χ², Fisher exact test, and multivariate logistic regression models.

RESULTS

Overall, SR rates were 21% for patients in the standard schedule and 37% for patients in the cluster immunotherapy schedule, which was not statistically different (P = .08). However, the SR rate for each injection was 0.69% per injection in the standard protocol and 2.29% per injection in the cluster schedule (incident rate ratio = 3.3). All SRs (100%) in both groups occurred in the second half of the build-up phase. Multivariate regression revealed that the target prescription protein nitrogen units and the number of allergens in the treatment vial did not influence SR rates (odds ratio = 1.00 and 1.06, respectively).

CONCLUSION

The overall incidence of SR was not statistically different for cluster and standard AIT protocols. However, because cluster patients received approximately half the number of injections, the risk for SR per individual injection is more than 3-fold higher than that of standard immunotherapy.

Is allergy immunotherapy-induced anaphylaxis still a real problem?

PURPOSE OF REVIEW

The current review describes the incidence and risk for anaphylaxis due to allergy injections.

RECENT FINDINGS

The incidence of fatal anaphylaxis occurs with approximately one in 7.2 million injection visits. Severe anaphylaxis may occur once in every 160 000 visits. The major risk for fatal anaphylaxis is severe and uncontrolled asthma.

SUMMARY

Understanding risk factors for anaphylaxis to allergy injections has led to clinic protocols aimed at preventing such events. The efficacy of these preventive measures remains to be determined in future studies.

Is immunotherapy safe for treatment of severe asthma

PURPOSE OF REVIEW

The benefits of allergen immunotherapy (AIT), including subcutaneous allergen immunotherapy (SCIT) and sublingual allergen immunotherapy (SLIT), for IgE-mediated asthma are well established, especially for dust mite. This review will explore whether the benefits of AIT outweigh the risks in severe asthmatic patients.

RECENT FINDINGS

Studies have mostly included mild and moderate asthmatic patients, but at least a few studies do show improvements in asthma symptoms and medication use in severe asthmatic patients. Asthma, and especially uncontrolled asthma, is a major risk factor for severe and fatal systemic reactions from SCIT. Uncontrolled asthma is an absolute contraindication for SCIT. It is less clear whether the benefits of SCIT and SLIT may outweigh the risks in well controlled, severe asthmatic patients, and further study is needed in this area. Asthma biologics, especially Omalizumab, may improve outcomes in severe, controlled asthmatic patients on SCIT, but further data are needed regarding timing of initiation and duration of treatment.

SUMMARY

Although severe asthmatic patients may benefit from AIT, significant risks exist, especially in those with uncontrolled asthma. Further study is needed regarding optimal strategies to minimize risks.

Advances in Evaluation and Treatment of Severe Asthma (Part One)

As many as 15% to 20% of patients with asthma have incompletely or poorly controlled asthma despite treatment with inhaled corticosteroids and long-acting beta-agonist bronchodilators. They are vulnerable to burdensome symptoms, limitations to their exercise capacity, and asthma attacks that can be frightening and potentially life-threatening. This article outlines a systematic approach to their evaluation, attempting to identify remediable factors that are making their asthma more severe than most other persons with asthma. This approach includes an emphasis on ensuring the correct diagnosis, minimizing exposures to stimuli that worsen airway inflammation, alleviating modifiable comorbidities such as chronic rhinosinusitis and gastroesophageal reflux, and supporting regular medication adherence and effective technique for administering inhaled medications. A basic diagnostic laboratory work-up is recommended, to be modified and amplified according to individual patient needs.

Cost-effectiveness analysis of house dust mite allergen immunotherapy in children with allergic asthma

BACKGROUND

Cost-effectiveness studies evaluating allergen immunotherapy (AIT) in children are limited but needed to drive clinical and policy-making decisions such as reimbursement of new interventions. In this study, we compared the cost effectiveness of subcutaneous (SCIT) and sublingual immunotherapy (SLIT) tablets to the standard of care (SOC) treatment in children with house dust mite-driven (HDM) allergic asthma.

METHODS

We developed a hypothetical Markov model based on the Global Initiative for Asthma (GINA) severity steps to compare the three strategies over a 10-year horizon divided by cycles of 6 months. SOC was used as a reference to calculate the incremental cost-effectiveness ratio (ICER). Deterministic and probabilistic sensitivity analyses were used to assess models' uncertainty. Other scenarios were evaluated to strengthen the presentation of results.

RESULTS

The ICER for SCIT and SLIT tablets was 1281€ and 7717€, respectively. The cost-effectiveness threshold for Portugal was 18,482.80€; both treatment approaches were below this limit. The major contributors to these results were the AIT effects on reducing moderate and severe exacerbations and asthma controller medication. In the sensitivity analysis, SCIT revealed a higher probability of cost-effectiveness than SLIT. When including allergic rhinitis as comorbidity, ICER values reduced markedly, especially for SCIT intervention.

CONCLUSIONS

AIT was cost effective in children with HDM-driven allergic asthma, especially when given by the subcutaneous route. The high probability of cost effectiveness, especially for SCIT, may drive future policy decisions and AIT-prescribing habits. AIT adherence greatly influenced the results highlighting the value of implementing strategies to promote adherence rates.

Safety of subcutaneous immunotherapy with carbamylated allergoids based on data from a pharmacovigilance database

Aims: Allergen immunotherapy aims to induce tolerance, which persists after its discontinuation, to targeted allergens. However, concern exists regarding the use of subcutaneous immunotherapy with whole extracts due to frequently reported events of anaphylactic reactions. Materials & methods: In this pharmacovigilance study, the authors assessed the safety of subcutaneous immunotherapy with the monomeric allergoid Lais-in using a database of adverse reactions documented in real-world postmarketing reports from 2010 to 2020. Results & conclusion: The results showed that more than 171,916 doses of Lais-in were administered from 2010 to 2020, resulting in five adverse drug reactions. Nonserious adverse events, including hives, eye irritation and skin reactions, were reported. These data indicate that monomeric allergoids prevent serious reactions to subcutaneous immunotherapy.

Safety of Subcutaneous Immunotherapy in Patients with Severe Asthma

BACKGROUND

Severe asthma (SA) has been identified as a risk factor for severe systemic reactions (SR) to allergen subcutaneous immunotherapy (SCIT). However, the incidence and characterization of SRs in SA in comparison to less severe or no asthma is not known.

OBJECTIVE

The objective of this study was to characterize the incidence of SRs in SA patients receiving SCIT in comparison to patients with no asthma or less severe asthma.

METHODS

A retrospective cohort study was performed of patients receiving SCIT from a multicenter national network of private allergy practices between January 2015 to December 2019. Demographics, asthma severity (ICD-10 codes), concomitant medications, aeroallergen skin testing, measures of asthma control with the asthma control test (ACT) and FEV1 values, SCIT prescription, and a SR standardized form were assessed.

RESULTS

65,855 patients, with 1072 SA patients, receiving SCIT were included with a total of 4415 SRs (19.9 SR per 10,000 injection visits). SA had 23.9 SRs per 10,000 injection visits (incidence rate 0.239; 95% CI [0.189, 0.298). There were 155 grade III/IV SRs; 5 (3.2%) occurred in SA group. There was no difference in rates of grade III/IV SRs between SA and no asthma as well as in rates of total SRs between SA and less severe asthma.

CONCLUSION

In a large cohort of patients with SA undergoing multi-allergen SCIT drawn from a diverse outpatient allergy population, the diagnosis of SA was not associated with increased moderate-severe SRs compared to patients without asthma and any severity of asthma.

CLINICAL TRIAL REGISTRATION

Not applicable.

Pharmacological Management of Allergic Rhinitis: A Consensus Statement from the Malaysian Society of Allergy and Immunology

The goal of allergic rhinitis (AR) management is to achieve satisfactory symptom control to ensure good quality of life. Most patients with AR are currently treated with pharmacotherapy. However, knowledge gaps on the use of pharmacotherapy still exist among physicians, particularly in the primary care setting, despite the availability of guideline recommendations. Furthermore, it is common for physicians in the secondary care setting to express uncertainty regarding the use of new combination therapies like intranasal corticosteroid plus antihistamine combinations. Inadequate treatment leads to significant reduction of quality of life that affects daily activities at home, work, and school. With these concerns in mind, a practical consensus statement was developed to complement existing guidelines on the rational use of pharmacotherapy in both the primary and secondary care settings.

Safety of subcutaneous allergen immunotherapy

Subcutaneous allergen immunotherapy (SCIT) is a unique treatment option for managing patients with allergic rhinitis, asthma, atopic dermatitis, and stinging insect allergy. Although systemic reactions to allergen injections are rare, near-fatal, and fatal anaphylactic reactions can occur. Patients with asthma are at greatest risk for more severe reactions as are those with previous systemic reactions. Treating allergists should institute best clinical practices to prevent and manage severe systemic reactions to SCIT, including the following: (1) prescreening patients with asthma for recent increases in asthma symptoms, (2) not prescribing SCIT to patients with severe and uncontrolled asthma, (3) instituting clinic protocols to prevent dosing errors, (4) considering modifying allergen doses during peak allergy seasons in patients at high risk, (5) instituting measures that require all patients on SCIT to be observed for at least 30 minutes after injections, and (6) regular training of all clinical staff in the recognition and expeditious treatment of anaphylaxis.

Immunotherapy for Asthma

Asthma represents one of the biggest global health concerns with increasing prevalence and influence on global health. Several distinct asthma phenotypes have been identified with one of the most common, earliest recognized, and described being the allergic asthma phenotype, in which allergens trigger asthma through mechanisms involving allergen-specific immunoglobulin E (IgE). Allergen-specific immunotherapy (AIT), in the forms of subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT), has been used for many decades as a tool for reducing IgE-mediated sensitization and controlling symptoms of allergic disease, most commonly for allergic rhinitis, and it remains the only currently available disease modifying therapy in atopic patients. AIT has been studied for use in mild to moderate allergic asthma. While the data are often inconsistent, and utilize a multitude of different methods, antigens, and outcome measures, in general, AIT may have several beneficial effects on asthma disease control, quality of life, and requirement for medication. These benefits are notable when immunotherapy is used as an adjunct to pharmacologic treatment in carefully selected and monitored patients with mild to moderate persistent asthma. Patients with severe asthma are excluded from these trials. Importantly, patients with asthma, and in particular severe asthma, may have a higher rate of systemic adverse reactions to SCIT, including anaphylaxis, however, these events are overall rare. Future research in the area is needed to definitively assess the benefit of SCIT and SLIT for patients with asthma, comparing outcomes with different methods, addressing the role of AIT in severe asthma, significance of multiallergen AIT in allergic asthma, and safety concerns in asthma.

Venom Immunotherapy and Aeroallergen Immunotherapy: How Do Their Outcomes Differ?

Allergen immunotherapy (AIT) and venom immunotherapy (VIT) are meant to work on the causes of allergies, respectively, to respiratory allergens and Hymenoptera venom, inducing tolerance to the allergens and modifying the natural history of allergy. Both types of immunotherapies have evidence of efficacy, but actually they present wide differences in both effectiveness and safety. Indeed, as far as the effectiveness of VIT is concerned, if the protection against fatal reactions to stings is considered as the primary objective, more than 40 years of clinical practice demonstrate complete success. The clinical success of AIT is measurable on the basis of reduction or disappearance of allergic symptoms. The difference between the two treatments is even higher as regards safety: AIT has been concerned in the past by a series of fatal reactions caused, which underwent a progressive decrease when it was understood that they were related to the presence of uncontrolled asthma. However, fatal reactions related to failure to recognize the presence of risk factors or administration errors are still reported. Similarly to what has been observed for efficacy, VIT has never been affected by fatal reactions to the administration of venom, and the most important risk of anaphylaxis, which is the concomitance of mastocytosis, is now identified by measuring its marker serum tryptase. To date, mechanisms of hypersensitivity reactions that differentiate respiratory allergy from Hymenoptera venom allergy have not been successfully demonstrated. We have examined the past and present literature in order to propose reasonable hypotheses about the mechanisms actually involved.

Systemic Allergic Reactions and Anaphylaxis Associated with Allergen Immunotherapy

Subcutaneous allergen immunotherapy (SCIT) is a proven treatment of allergic rhinitis, asthma, atopic dermatitis, and prevention of Hymenoptera venom anaphylaxis. The known benefit of SCIT, however, must be considered in each patient relative to the potential risks of systemic allergic reactions (SRs). A mean of 1 SR per 1000 injection visits (0.1%) was estimated to occur between 2008 and 2018. Life-threatening anaphylactic events are estimated to occur in 1/160,000 injection visits. The factors that contribute to SRs and fatal reactions (FRs) are reviewed. Risk management strategies are proposed to prevent and decrease future SCIT associated with SRs, anaphylaxis, and FR.

Anaphylaxis Associated With Allergen Specific Immunotherapy, Omalizumab, and Dupilumab: A Real World Study Based on the US Food and Drug Administration Adverse Event Reporting System

Background: Real-world studies on the allergen specific immunotherapy (AIT), omalizumab, and dupilumab associated anaphylactic events are limited. We aimed to analyze the characteristics of drug associated anaphylaxis, and to compare the differences among different drugs. Methods: A disproportionality analysis and Bayesian analysis were used in data mining to identify suspected anaphylaxis associated with AIT, omalizumab, and dupilumab based on the Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) from January 2004 to March 2021. Demographic information, time interval to onset, and death rates of AIT, omalizumab, and dupilumab associated anaphylaxis were also analyzed. Results: Totally 9,969 anaphylactic events were identified. Reports of AIT, omalizumab, and dupilumab associated anaphylactic events were 64, 7,784, and 2,121, respectively. AIT had a high reporting odds ratio (ROR) of 5.03 [95%confidental interval (CI) 3.69-6.85], followed by omalizumab (ROR 2.24, 95% CI 2.18-2.29), and dupilumab had a negative signal for anaphylaxis. In children, most anaphylactic reactions (68%) were reported in the 12-17-year-old group. More reports of anaphylaxis related to AIT were in boys (73%), while more reports of anaphylaxis related to omalizumab (63%) and dupilumab (58%) were in girls. Most symptoms occurred on the day of drug initiation. The death rate of AIT related anaphylaxis was the lowest (0%), the death rate of omalizumab was 0.87%, while the death rate of dupilumab was 4.76%. No significant differences were observed among these drugs. Conclusion: AIT and omalizumab had a positive signal for anaphylaxis, while dupilumab had a negative signal for anaphylaxis. Patients should be strictly monitored after administration of AIT and also biologics. It also gives us a suggestion for choosing a combined biologics with AIT when the risk of anaphylaxis was considered.