Idiopathic anaphylaxis: Diagnosis and management

Introduction: Idiopathic anaphylaxis (IA) is a diagnosis of exclusion and is based on the inability to identify a causal relationship between a trigger and an anaphylactic event, despite a detailed patient history and careful diagnostic assessment. The prevalence of IA among the subset of people who experienced anaphylaxis is challenging to estimate and varies widely, from 10 to 60%; most commonly noted is ∼20% in the adult anaphylactic population. Comorbid atopic conditions, such as food allergy, allergic rhinitis, and asthma, are present in up to 48% of patients with IA. Improved diagnostic technologies and an increased understanding of conditions that manifest with symptoms associated with anaphylaxis have improved the ability to determine a more accurate diagnosis for patients who may have been initially diagnosed with IA. Methods: Literature search was conducted on PubMed, Google Scholar and Embase. Results: Galactose-α-1,3-galactose (α-gal) allergy, mast cell disorders, and hereditary a-tryptasemia are a few differential diagnoses that should be considered in patients with IA. Unlike food allergy, when anaphylaxis occurs within minutes to 2 hours after allergen consumption, α-gal allergy is a 3‐6-hour delayed immunoglobulin E‐mediated anaphylactic reaction to a carbohydrate epitope found in red meat (e.g., beef, lamb, pork). The more recently described hereditary α-tryptasemia is an inherited autosomal dominant genetic trait caused by increased germline copies of tryptase human gene alpha-beta 1 (TPSAB1), which encodes α tryptase and is associated with elevated baseline serum tryptase. Acute management of IA consists of carrying an epinephrine autoinjector to be administered immediately at the first signs of anaphylaxis. Long-term management for IA with antihistamines and other agents aims to potentially reduce the frequency and severity of the anaphylactic reactions, although the evidence is limited. Biologics are potentially steroid-sparing for patients with IA; however, more research on IA therapies is needed. Conclusion: The lack of diagnostic criteria, finite treatment options, and intricacies of making a differential diagnosis make IA challenging for patients and clinicians to manage.

Evaluation of anaphylaxis recurrence and adrenaline autoinjector use in childhood

Introduction: Limited data are available on recurrent anaphylaxis in childhood. Delayed adrenaline administration is the major cause of deaths due to anaphylaxis. As well as prescribing the adrenaline autoinjector (AAI), it is important to make sure that the patient carries the device at all times and uses it correctly for the appropriate indication. Objective: The aim of our study was to evaluate the recurrence of anaphylaxis and AAI use in childhood. Methods: Pediatric patients who were evaluated for anaphylaxis and prescribed AAI between January 2015 and December 2018, in the pediatric allergy and immunology clinic of our hospital were screened retrospectively. A telephone-based survey was conducted with the parents of the patients to investigate the recurrence of anaphylaxis in patients and the use of AAI by their parents for the management of anaphylaxis. Results: A total of 148 patients (64.9% boys) were prescribed an AAI for anaphylaxis. The telephone survey could be conducted with 111 parents (75%) with an AAI prescription. Of these patients, 23.4% (n = 26) of the parents reported that their children experienced recurrent episodes of anaphylaxis. In the recurrent anaphylaxis cases, the triggers were foods in 77%, venoms in 11.5%, drugs in 3.8%, and idiopathic anaphylaxis in 7.7% of the patients. AAI use at the time of anaphylaxis was reported by 42.3% of the parents. The reasons cited by the parents for not using AAI during an episode of anaphylaxis included the preference to have adrenaline administered at a health care facility because of its proximity (60%), fear of using the device (13.3%), hesitation (6.7%), not having the device with them (13.3%), and unavailability of the device (6.7%). Conclusion: Educating the patients and families about the importance of using AAI is crucial, and training on how to use the device should be repeated at each clinic visit and every opportunity.

Idiopathic Anaphylaxis: a Perplexing Diagnostic Challenge for Allergists

Purpose of Review The aim of this systematic review is to present the proposed theories of pathogenesis for idiopathic anaphylaxis (IA), to discuss its classification, its diagnostic approach, and management. Recent Findings IA represents a major diagnostic challenge and is diagnosed when excluding the possible identifiable triggers of anaphylaxis. The current research, however, revealed that certain conditions including mastocytosis, mast cell activation syndromes, and hereditary alpha tryptasemia can masquerade and overlap with its symptomatology. Also, newly identified galactose-alpha-1,3-galactose mammalian red meat allergy has recently been recognized as underlying cause of anaphylaxis in some cases that were previously considered as IA. Summary IA comprises a heterogenous group of conditions where, in some cases, inherently dysfunctional mast cells play a role in pathogenesis. The standard trigger avoidance strategies are ineffective, and episodes are unpredictable. Therefore, prompt recognition and treatment as well as prophylaxis are critical. The patients should always carry an epinephrine autoinjector.

Idiopathic Anaphylaxis: A Diagnosis of Exclusion

We report the case of a 67-year-old female with hypertension and rheumatoid arthritis who had 5 unprovoked episodes of anaphylaxis in an 18-month period of time. We review idiopathic anaphylaxis, including its definition, diagnostic work-up, and differential diagnosis.