Systemic Allergic Reactions and Anaphylaxis Associated with Allergen Immunotherapy

Anaphylaxis in Practice: A Guide to the 2023 Practice Parameter Update

This review summarizes new research developments and clinical practice recommendations for the diagnosis and management of anaphylaxis presented in the Joint Task Force on Practice Parameters 2023 Anaphylaxis practice parameter Update. It is intended to serve as a high-level summary of the 2023 practice parameter, which makes clinically impactful recommendations based on evidence that has emerged since the 2015 practice parameter. We invite clinicians to explore the full 2023 practice parameter to understand the research methods and underlying evidence that have informed the recommendations summarized here. There are new and evolving diagnostic criteria for anaphylaxis, rules for defining elevated tryptase levels, and recognition of signs and symptoms particular to infants and toddlers. The administration of epinephrine should not be used as a surrogate to diagnose anaphylaxis. Risk factors for anaphylaxis should be assessed on a case-by-case basis. Patient counseling and shared decision-making are essential to support patients' treatment decisions and capacity to manage the risk of anaphylaxis at home and in other community settings. Activation of emergency medical services after home epinephrine administration may not be required in all cases, and patients should be engaged in shared decision-making to determine when home management may be appropriate.

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.

Allergic Rhinitis: A Review

Importance

Allergic rhinitis affects an estimated 15% of the US population (approximately 50 million individuals) and is associated with the presence of asthma, eczema, chronic or recurrent sinusitis, cough, and both tension and migraine headaches.

Observations

Allergic rhinitis occurs when disruption of the epithelial barrier allows allergens to penetrate the mucosal epithelium of nasal passages, inducing a T-helper type 2 inflammatory response and production of allergen-specific IgE. Allergic rhinitis typically presents with symptoms of nasal congestion, rhinorrhea, postnasal drainage, sneezing, and itching of the eyes, nose, and throat. In an international study, the most common symptoms of allergic rhinitis were rhinorrhea (90.38%) and nasal congestion (94.23%). Patients with nonallergic rhinitis present primarily with nasal congestion and postnasal drainage frequently associated with sinus pressure, ear plugging, muffled sounds and pain, and eustachian tube dysfunction that is less responsive to nasal corticosteroids. Patients with seasonal allergic rhinitis typically have physical examination findings of edematous and pale turbinates. Patients with perennial allergic rhinitis typically have erythematous and inflamed turbinates with serous secretions that appear similar to other forms of chronic rhinitis at physical examination. Patients with nonallergic rhinitis have negative test results for specific IgE aeroallergens. Intermittent allergic rhinitis is defined as symptoms occurring less than 4 consecutive days/week or less than 4 consecutive weeks/year. Persistent allergic rhinitis is defined as symptoms occurring more often than 4 consecutive days/week and for more than 4 consecutive weeks/year. Patients with allergic rhinitis should avoid inciting allergens. In addition, first-line treatment for mild intermittent or mild persistent allergic rhinitis may include a second-generation H1 antihistamine (eg, cetirizine, fexofenadine, desloratadine, loratadine) or an intranasal antihistamine (eg, azelastine, olopatadine), whereas patients with persistent moderate to severe allergic rhinitis should be treated initially with an intranasal corticosteroid (eg, fluticasone, triamcinolone, budesonide, mometasone) either alone or in combination with an intranasal antihistamine. In contrast, first-line therapy for patients with nonallergic rhinitis consists of an intranasal antihistamine as monotherapy or in combination with an intranasal corticosteroid.

Conclusions and Relevance

Allergic rhinitis is associated with symptoms of nasal congestion, sneezing, and itching of the eyes, nose, and throat. Patients with allergic rhinitis should be instructed to avoid inciting allergens. Therapies include second-generation H1 antihistamines (eg, cetirizine, fexofenadine, desloratadine, loratadine), intranasal antihistamines (eg, azelastine, olopatadine), and intranasal corticosteroids (eg, fluticasone, triamcinolone, budesonide, mometasone) and should be selected based on the severity and frequency of symptoms and patient preference.

Long-Term Efficacy and Safety of Subcutaneous Immunotherapy in Monosensitized and Polysensitized Children With Allergic Rhinitis

OBJECTIVE

To evaluate the efficacy and safety of dust mite subcutaneous immunotherapy (SCIT) in monosensitized and polysensitized children with allergic rhinitis (AR).

STUDY DESIGN

Prospective cohort study.

SETTING

Tertiary referral center.

METHODS

One hundred thirty children were enrolled and categorized into 2 groups: monosensitized to only dust mites and polysensitized to at least 1 additional allergen beyond dust mites. All patients received SCIT targeting dust mites for 3 years, followed by a 5-year monitoring period. The Total Nasal Symptom Score (TNSS), Symptom and Medication Score (SMS), Visual Analogue Scale (VAS), and Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) were assessed before SCIT (T0); at 1 (T1) and 2 (T2) years of SCIT; immediately after SCIT (T3); and 2 years post-SCIT (T5). Safety was assessed based on adverse events (AEs).

RESULTS

Fifty-one monosensitized and 50 polysensitized children completed the study. At T3, 47 monosensitized and 46 polysensitized children were effectively treated, with no significant between-group difference in efficacy (P > .05). The TNSS, SMS, VAS scores, and RQLQ score were significantly lower at T1, T2, T3, and T5 than at T0 in both groups (P < .05). The differences in the TNSS, SMS, VAS score, and RQLQ score between the 2 groups were nonsignificant at T0, T1, T2, and T3 (P > .05), but significant at T5 (P < .05). No serious AEs were reported.

CONCLUSION

Monosensitized and polysensitized children exhibited similar beneficial efficacy and safety after 3 years of dust mite SCIT. Monosensitized children derived more benefits 2 years after discontinuation.

Anaphylaxis: A 2023 practice parameter update

This practice parameter update focuses on 7 areas in which there are new evidence and new recommendations. Diagnostic criteria for anaphylaxis have been revised, and patterns of anaphylaxis are defined. Measurement of serum tryptase is important for diagnosis of anaphylaxis and to identify underlying mast cell disorders. In infants and toddlers, age-specific symptoms may differ from older children and adults, patient age is not correlated with reaction severity, and anaphylaxis is unlikely to be the initial reaction to an allergen on first exposure. Different community settings for anaphylaxis require specific measures for prevention and treatment of anaphylaxis. Optimal prescribing and use of epinephrine autoinjector devices require specific counseling and training of patients and caregivers, including when and how to administer the epinephrine autoinjector and whether and when to call 911. If epinephrine is used promptly, immediate activation of emergency medical services may not be required if the patient experiences a prompt, complete, and durable response. For most medical indications, the risk of stopping or changing beta-blocker or angiotensin-converting enzyme inhibitor medication may exceed the risk of more severe anaphylaxis if the medication is continued, especially in patients with insect sting anaphylaxis. Evaluation for mastocytosis, including a bone marrow biopsy, should be considered for adult patients with severe insect sting anaphylaxis or recurrent idiopathic anaphylaxis. After perioperative anaphylaxis, repeat anesthesia may proceed in the context of shared decision-making and based on the history and results of diagnostic evaluation with skin tests or in vitro tests when available, and supervised challenge when necessary.

Knowledge mapping of immunotherapy for thyroid cancer from 1980 to 2022: A review

With the gradual development of immunotherapy for thyroid cancer, relevant research has increased. To better understand the current situation, development trend, evolution process, and research hotspots of this field, we conducted this comprehensive bibliometrics visual analysis. We retrieved papers published from 1980 to 2022 from Web of Science Core Collection on January 31, 2023. CiteSpace, Pajek, VOSviewer, R-Bibliometrix, and Scimago Graphics are the tools to perform the analysis. Analysis methods mainly include co-occurrence analysis and cluster analysis. Analysis objects are countries or regions, institutions, authors, journals, and keywords, etc. In terms of publication number, the recent decade has witnessed rapid growth. USA was the most prolific country and has the most influence in the cooperation team. Sweden took the lead in focus on this research field and lasted for 21 years. Garden State Cancer Center was released most papers (28). INSERM played a major role in institutional cooperation. Goldenberg DM published the most papers (48), with H-Index 25 and G-Index 43. Journal of Nuclear Medicine has the greatest papers published (41). The average impactor factor of the top 10 journals is 7.2058. The top keywords with high burst strength are: radioimmunotherapy (14.85), monoclonal antibody (13.78), non hodgkins lymphoma (12.54). The research field of immunotherapy for thyroid cancer will be further developed. This study provides a valuable reference for future research in the field.

Different age groups present different clinics in anaphylaxis with children: one size does not fit all children

BACKGROUND

Childhood anaphylaxis presents with a heterogeneous clinic. Elicitors and epidemiologic factors associated with anaphylaxis differ with age, geographic location and lifestyle. This study aimed to determine the clinical features and age-specific patterns of childhood anaphylaxis in a single referral center in Turkey.

METHODS

We conducted a retrospective study of anaphylaxis in children aged between 0 and 18 years of age, attending an allergy department in a children's hospital.

RESULTS

A total of 95 children diagnosed with anaphylaxis were analyzed. Among all, 35.8% of the first anaphylaxis episodes occurred ininfancy and 57.9% in preschool age. Foods were the most common culprits (57.9%) and followed by drugs (15.8%). Patients with foodinduced anaphylaxis were younger in age (p < 0.001). Food-related anaphylaxis was most common with cow's milk (36.4%) and followed by tree nuts (20%). Cow's milk played a significant role as a trigger in infancy, and tree nuts as a trigger in preschoolers and school-age children. Mucocutaneous manifestations were almost universally present (94.7%), followed by respiratory compromise (56.8%), with gastrointestinal (55.8%), cardiovascular (9.5%), and neurologic (4.2%) symptoms being less common. Respiratory and cardiovascular system-related symptoms were found more frequently in school-age children (p = 0.02 and p = 0.014, respectively). The severity of anaphylaxis was higher in school-age children (p = 0.015).

DISCUSSION

Findings reveal that children diagnosed with anaphylaxis differ in terms of etiological and clinical findings according to age groups. This difference shows the dynamically changing clinic of anaphylaxis over time and the importance of evaluating childhood anaphylaxis according to age groups.

Dose Adjustment After Gaps in Administration of Subcutaneous Immunotherapy From a Past Survey: Work Group Report of the AAAAI Allergen Standardization and Allergy Diagnostics Committee

The allergen immunotherapy practice parameters third update recommendations on dose adjustment after a gap in administration during the build-up are based solely on expert opinion, and no recommendations for gaps during maintenance are given. In a previous survey among American Academy of Allergy, Asthma & Immunology (AAAAI) members on subcutaneous allergen immunotherapy, this was addressed, but details were never published. Members of the Immunotherapy, Allergen Standardization, and Allergy Diagnostics Committee of the AAAAI convened a workgroup to address this issue and reanalyze results on the particular survey section. Build-up: many practitioners start dose-adjusting if a patient comes in 14.1/14 days (mean/median) after the last dose and restart immunotherapy after an interruption of 85/90 days. Dosing frequency during maintenance is generally every 3 (12%) to 4 weeks (73%). Maintenance: allergists start dose-adjusting if a patient comes in 5.1/5 weeks (mean/median) after the last dose and completely restart after an interruption of 16/12 weeks (some replied in days [90.4/90 days] or months [4.43/4 months]). Subgroups: physicians with ≥11 years in practice in nonacademic centers or rural/suburban settings tolerate longer gaps before restarting subcutaneous immunotherapy (SCIT). There is no uniform dose-adjustment protocol after gaps in SCIT administration. Prospective studies shall have to help find the best trade-off between safety (dose reduction) without giving in on efficacy (too much dose reduction).

Chinese Guideline on Allergen Immunotherapy for Allergic Rhinitis: The 2022 Update

In the last few decades, there has been a progressive increase in the prevalence of allergic rhinitis (AR) in China, where it now affects approximately 250 million people. AR prevention and treatment include allergen avoidance, pharmacotherapy, allergen immunotherapy (AIT), and patient education, among which AIT is the only curative intervention. AIT targets the disease etiology and may potentially modify the immune system as well as induce allergen-specific immune tolerance in patients with AR. In 2017, a team of experts from the Chinese Society of Allergy (CSA) and the Chinese Allergic Rhinitis Collaborative Research Group (C2AR2G) produced the first English version of Chinese AIT guidelines for AR. Since then, there has been considerable progress in basic research of and clinical practice for AIT, especially regarding the role of follicular regulatory T (TFR) cells in the pathogenesis of AR and the use of allergen-specific immunoglobulin E (sIgE) in nasal secretions for the diagnosis of AR. Additionally, potential biomarkers, including TFR cells, sIgG4, and sIgE, have been used to monitor the incidence and progression of AR. Moreover, there has been a novel understanding of AIT during the coronavirus disease 2019 pandemic. Hence, there was an urgent need to update the AIT guideline for AR by a team of experts from CSA and C2AR2G. This document aims to serve as professional reference material on AIT for AR treatment in China, thus improving the development of AIT across the world.