Egg-allergic Patients Research Articles

No Yellow Fever Vaccine Reactions in IgE-Mediated Egg Allergic Patients

Introduction: Egg allergy usually manifests during the initial 2 years of life, a period in which most vaccinations are administered. This often leads to delays in the application of some vaccines in patients with egg allergies, exposing them to a risk of contracting preventable infections. The aim of the study was to describe the frequency of reactions after applying the yellow fever vaccine (YFV) within a population with egg allergy. Methods: This was a cohort study with retrospective, multicenter data (2014–2023). Patient records diagnosed with egg allergy were gathered from their initial egg-related reactions until their YFV administration. Information was also collected about hypersensitivity tests conducted for egg and YFV such as the skin prick test (SPT) and intradermal test (IDT). Results: Among the 171 records analyzed, 23.9% of patients had a history of egg anaphylaxis. Out of these, 5 patients had a positive SPT and 21 IDT with the YFV. All patients tolerated the application of YFV without developing hypersensitivity reactions, regardless of the results of the YFV tests, the severity of egg reactions, the number of egg reactions, or the time since the last egg reaction. Out of the total patient cohort, 46.1% (79 individuals) encountered delays in receiving the YFV, and in this subset, 14% faced delays lasting longer than 12 months. Conclusion: The risk of allergic reactions with the YFV remains low. YFV tests generate delays in the vaccine application without providing high diagnostic accuracy. YFV should not be deferred even in patients with a history of severe egg reactions.

Immunological and molecular study in children with combined immunodeficiency.

Background. Severe combined immunodeficiency (SCID) is a form of immunodeficiencies (PID), caused by molecular defects. These defects can restrict the development and function of lymphocytes. Early diagnosis and treatment of SCID can lead to disease-free survival. This study aims to investigate some of the possible underlying genetic defects in a group of Egyptian infants and children with clinical and immunological profiles suggestive of SCID. Methods. This study included eighty patients who showed clinical warning signs of immunodeficiency. Subjects were thoroughly examined clinically. Laboratory evaluation included immunoglobulins serum levels and flow cytometric assessment of immune cells. This testing showed an altered immune profile in thirty patients. They had decreased T and/or B lymphocytes or natural killer cells. DNA extraction was done for those cases. The coding regions of the RAG1 gene and RAG2 gene was investigated for hot spot mutations by sequencing technique guided by the patient clinical evaluation, inheritance pattern, immunophenotyping by flow cytometric analysis of lymphocyte subsets, and serum immunoglobulins level detection. Results. Results showed novel and previously reported variants (mutation, polymorphism), they were found in 18 cases which include variants in the RAG1 gene (E880K, A960A, H249R, S913R, K820R, V782G), and variants in the RAG2 gene (P501T, L514M, rs10836573, cDNA.2129A>T). Conclusions. To evaluate SCID patients completely, mutation gene analysis is highly required and recommended.

Factors effecting natural course of egg allergy.

Background. There is limited data about the natural course of egg allergy in the literature. We aimed to analyze the factors that can affect the tolerance or persistence of egg allergy. Methods. A total number of 126 IgE- mediated egg allergic patient who had data about tolerance gaining were included in the study. Demographic and laboratory data were recorded retrospectively. Kaplan-Meier curves was used for estimation of resolution and the factors related to resolution by Cox regression model. Results. Among 126 patients 81 (64.2%) had gained tolerance with a median survival time of 48 months (min 12- max 121). Tolerance was gained in 22.2% (28) of these patients in the first 2 years, in 46.8% (49) 2-6 years, 3.1% (4) between 7-12 years. In univariate analysis, no history of anaphylaxis (at initiation or during OFC) (Hazard ratio 2.193; 95%CI 1.309-3.674, p = 0.003), baseline sIgE level less than 8.2 (Hazard ratio 11.292; 95%CI 2.766-46.090, p = 0.001) and baseline egg SPT less than 11 mm (Hazard ratio 2.906; 95%CI 1.424-5.930, p = 0.003) were found to be related to earlier resolution of egg allergy. In multivariate analysis only anaphylaxis was significantly related to later resolution (Hazard ratio: 6.547; 95%CI 15.80-27.434, p = 0.01). Conclusions. Higher levels of egg sIgE, skin prick test induration and anaphylaxis at onset or during oral food challenge, can give hint about persistence of egg allergy.

Food Matrix Composition Affects the Allergenicity of Baked Egg Products

BackgroundEgg allergy is common and caused by sensitization to ovomucoid and/or ovalbumin. Many egg-allergic patients are able to tolerate eggs baked into other foods, such as muffins. While heating egg extensively reduces allergens, the effect of other food ingredients on allergenicity of eggs, or the “matrix effect,” is less well studied. ObjectiveWe aimed to define how food matrices impact the matrix effect in egg allergenicity. MethodsELISA was used to quantify ovalbumin and ovomucoid in extracts from various baked egg products: plain baked egg without a matrix, and muffins baked using either wheat flour, rice flour, or a wheat flour/banana puree mix. Allergen-specific IgE blocking ELISAs were performed using the egg product extracts on egg-allergic patient sera to determine whether the amount of extracted egg protein in each extract correlated with how well the extracts could bind patients’ egg IgE. ResultsBaking eggs in any muffin matrix led to an increase in the amount of extractable ovalbumin and a decrease in the amount of extractable ovomucoid compared to plain baked egg. Compared to wheat muffins, rice muffins had more extractable ovalbumin and wheat/banana muffins had more extractable ovalbumin and ovomucoid. The egg allergens in the extracts were able to block egg allergic patients’ egg IgE. ConclusionsFood matrices affect egg allergen availability. Patients and families should be advised that substitutions in baked egg muffin recipes can affect the amount of egg allergens in foods and potentially affect the risk of food allergic reaction.

Challenge-verified thresholds for allergens mandatory for labeling: How little is too much for the most sensitive patient?

It is mandatory to label food products with the 14 main allergens in the EU. Reasonable allergen labeling requires knowledge of population-based thresholds derived from food challenges. The aim of this study was to evaluate the threshold-distribution in clinically verified food allergic patients for allergens mandatory for labeling. All positive open oral food challenges and double-blind placebo-controlled food challenges (DBPCFC) performed at the Allergy Center, Odense University Hospital, Denmark (2000-2022) were included. For each included challenge, the cumulative threshold (LOAEL) was obtained and NOAEL estimated. Data were modelled as an interval censored log-normal distribution. Overall, 38 of all 2612 challenges (1.5%) in 1229 patients (717 male, 986 children) reacted to <5 mg protein. The majority of the most sensitive patients reacted with a Sampson severity score of 2-3. Using interval censored log-normal models only five groups (hens´ egg, fish, peanut, milk, tree-nuts) elicited reactions after ingestion of 0.5 mg protein and in low frequencies of the population. Hen's egg was the most potent allergen, with reactivity to <0.5 mg protein in 0.24% [0.13-0.44%] of egg allergic patients while the estimated fraction of allergic patients reacting to a eliciting dose on 0.5 mg protein for most other allergens were below 0.04%. Our data demonstrates that the majority of food allergic patients as expected tolerating traces of allergenic foods without developing severe allergic symptoms and signs. Hen's egg appears to be the food most likely to elicit reactions in the most sensitive individuals at very low doses.

Updates in food allergen immunotherapy.

Food allergies are on the rise. Though allergen avoidance and management of acute reactions have been the backbone of therapy, complete avoidance and timely acute care is often not feasible. Food allergen immunotherapy (FAIT) is a novel and evolving treatment option intended to induce desensitization and potential sustained unresponsiveness (SU) to food allergens. This review addresses the methods, mechanisms, efficacy, and adverse effects of oral immunotherapy (OIT), sublingual immunotherapy (SLIT), and epicutaneous immunotherapy (EPIT) for food allergens in the published literature. Single FAIT has been most extensively studied in peanut, milk, and hen's egg allergic patients and has been successful in achieving desensitization in treated individuals through various modalities. Long-term data regarding SU is limited; however, current data suggests subsets of patients may be more likely to achieve SU compared to others. Other studies are actively assessing multifood AIT and novel FAIT protocols with adjunctive therapies. Food allergy constitutes a prevalent problem with far-reaching consequences. The emergence of FAIT may mitigate the burden of food allergy. Current evidence is promising for specific allergens and pediatric patient populations. Future studies are needed to further assess efficacy between different modalities of immunotherapy for food allergens across an age continuum.

Allergenicity of Egg White Powder Compared to Baked Egg White Powder

There are several new products with baked egg powder marketed for possible prevention of food allergies. Previous studies have shown that standard egg white powder is equivalent to raw egg whites in allergenicity. It is known that heating destroys many conformational epitopes and reduces allergenicity in eggs, thus our aim was to compare the binding of serum IgE from egg-allergic patients to different formulations of egg white powders to evaluate the possible allergenicity of these baked egg products.

The Heterogeneity of Ovomucoid-Specific IgE Idiotype Is Associated With Egg Allergy Symptom Severity.

Immunoglobulin E (IgE)-mediated egg allergy presents as one of the most common food allergies. The level of specific IgE (sIgE) antibody is widely used as an important in vitro diagnostic indicator. However, sIgE antibody levels are often inconsistent with the clinical manifestations of patients. The heterogeneity of egg-specific IgE idiotypes (sIgE-IDs) may help reflect clinical egg allergy severity. Eight peptides were synthesized, corresponding to the linear epitopes of ovomucoid (OVM). The sIgE-IDs of egg-allergic patients were detected by enzyme-linked immunosorbent assay. Fresh peripheral blood was collected from patients with different heterogeneity strength of sIgE-ID, and egg extract was used as a stimulus to the basophil activation test (BAT). RBL-2H3 cells were sensitized with serum with different strength of sIgE-ID heterogeneity and the release rate of β-hexosaminidase was calculated. Among 75 patients with egg allergy, 24% had sIgE for all epitopes and 85% had sIgE for at least one epitope. Analysis of individual patients revealed differences in epitope recognition patterns among the patients, that is, heterogeneity in sIgE-ID. More importantly, the number of IgE-positive peptides had a strong correlation with allergic symptoms in egg-allergic patients (r = 0.706). BAT and RBL-2H3 cell degranulation confirmed that higher sIgE-ID heterogeneity strength was more effective in inducing effector cell responses. Our results suggest that the greater the heterogeneity strength of OVM-sIgE-ID, the more severe the allergic symptoms.

EGG ALLERGY AND YELLOW FEVER IMMUNIZATION: A SAFE DESENSITIZATION PLAN

<h3>Introduction</h3> Yellow fever is a viral hemorrhagic disease with a high-mortality rate endemic to tropical regions of South America and sub-Saharan Africa. While the egg-derived yellow fever vaccine (YF-VAX, Sanofi Pasteur, USA) is safe and provides life-long protection, it can pose a challenge for egg-allergic patients living in or traveling to endemic areas. <h3>Case Description</h3> We present the case of a successful desensitization to YF-VAX in a 10-month-old egg-allergic female traveling to Cameroon. The patient developed diffuse urticaria and facial angioedema with ingestion of boiled eggs at 6 months of age. Her egg white and component egg IgE testing was elevated. Skin prick testing (SPT) was positive to eggs and negative for 1:1 dilution of YF-VAX. Intradermal (ID) testing was positive to 1:10 dilution of YF-VAX. The patient successfully underwent a 5-step desensitization protocol. <h3>Discussion</h3> YF-VAX is a safe, effective immunization to prevent yellow fever. YF-VAX desensitization is easily tolerated and should be considered in egg-allergic patients at risk of complications resulting from the disease. While the American Academy of Pediatrics proposes a protocol to guide physicians in the desensitization of patients with suspected hypersensitivity reactions to immunizations, desensitization to YF-VAX in the United States is not a common occurrence as it is only recommended for people traveling to or living in endemic areas. Rutkowski et al. report a 7-step desensitization protocol of 4 egg-allergic patients with positive SPT to YFV. To our knowledge, this is the first reported case of successful YF-VAX desensitization in the United States using a 5-step desensitization protocol.

Peri-Operative Anaphylaxis - Antiquated Customs and News Towards the Culprits

Perioperative anaphylaxis occurs in about 1:6000 of all surgical procedures. Recently, the pathophysiology of anaphylactic reactions via mast cell related G-protein und complement-activated pseudo-allergy have been added to the "old" IgE mediated etiology. New culprits for anaphylactic reactions are chlorhexidine or gelatine as hemostypticum or blue surgical dyes to mark the situs. Biphasic anaphylactic reactions should be kept in mind. In the meantime, propofol use is allowed in egg and soybean allergic patients.

IMPACT OF EARLY BAKED EGG CHALLENGE ON LIFE QUALITY IN EGG-ALLERGIC PATIENTS VERSUS EGG AVOIDANCE

<h3>Introduction</h3> This study aims to evaluate the outcomes and impact of a flexible-dose early baked egg challenge on the quality of life for egg-allergic pediatric patients and their caregivers versus those who practice strict egg avoidance. <h3>Methods</h3> Patients were screened via chart review to determine eligibility and were enrolled during clinic visits and via phone call. Enrolled patients and caregivers provided written consent and completed a validated disease-specific health-related quality of life questionnaire, the Food Allergy Quality of Life Questionnaire (FAQLQ). The questionnaire evaluated the emotional impact of allergy, food anxiety, as well as social and dietary limitations. <h3>Results</h3> Twenty-six patients were included in the study (15 male, 11 female). Twenty-five patients were six years or younger, with one greater than eight years old. Twelve patients underwent a baked egg challenge versus fourteen who practiced complete egg avoidance. Patients were challenged to a baked egg recipe of the families' choice based on skin testing with the foods. Analysis of the two-sample t-test determined that patients who practice strict egg avoidance had higher FAQLQ scores compared to patients who have incorporated baked egg into their diet. The mean FAQLQ-PF score for egg avoidant patients was found to be 2.808 (SD 1.570) compared to 1.413 (SD 1.072) for baked egg tolerant patients (p=0.014). <h3>Conclusion</h3> Strict egg avoidance demonstrated a greater impairment in quality of life than those who have undergone a baked egg challenge and continue to incorporate baked egg into their diet.

Assessment of egg and milk allergies among Indians by revalidating a food allergy predictive model

BackgroundThe recent upsurge in food allergy indicates the need for accurate medical diagnostics. The application of predictive diagnostic models can envisage the outcome of oral food challenge (OFC), reducing cost and time. A logistic regression model was developed by DunnGalvin for children predicting OFC outcome using six predictors viz: sex, age, history, specific IgE, total IgE minus specific IgE, and skin prick test. This model was later updated by Klemans, reducing the number of predictors enhancing the calibration and discrimination of outcome. ObjectiveOur aim was to revalidate both the models for assessment of egg and milk allergies among Indians in the age group 0–19 years and to determine regression coefficients for our study population. MethodsRevalidation was done at the allergy clinic using OFC outcomes of egg and milk allergic patients. Precise values of the predictors were set up for which calibration (predicted against observed outcome) and discrimination (area under curve [AUC] of receiver operator characteristic curve [ROC]) would be better. ResultsThe Klemans model with reduced number of predictors showed better accuracy, calibration and discrimination than the DunnGalvin. Best calibration for egg allergy was achieved in the Klemans model with correlation coefficient (r2) of 0.90 and accuracy of 97%. The AUC of ROC was 0.90. For milk allergy, the coefficient was 0.94 with accuracy of 98%. The AUC was 0.91. ConclusionThe present study showed that mathematical models are non-invasive and can be successfully used as appropriate alternative to OFC in Indian population after proper validation.

The influence of acetylsalicylic acid and alcohol on absorption kinetics of hen´s egg white in a human passive cutaneous anaphylaxis model.

BackgroundDespite the well-known fact that acetylsalicylic acid (ASA) can induce anaphylaxis in patients susceptible to wheat-dependent exercise-induced anaphylaxis, few studies have sought to investigate the effects of cofactors on type-1 food allergy and none with ASA and hen’s egg and hen’s egg and alcohol combined.Methods and resultsWe applied the experimental model of ‘passive cutaneous anaphylaxis’ in humans to study whether the absorption kinetics of egg white is altered while being treated with ASA or under the influence of alcohol. Donor sera from four egg allergic patients with specific immunoglobulin E (s-IgE) to ovalbumin (0.1–8.87–19.5–170 kUA/L) were injected intracutaneously into the forearm of 12 healthy volunteers who were then challenged separately to: 1) egg white 2) egg white + ASA and 3) egg white + alcohol. ‘Time to wheal’ and ‘wheal size’ were compared among the three experiments.We saw that ‘time to wheal’ with both ASA (P = 0.001) and alcohol (P = 0.019) added as cofactor significantly decreased compared with baseline.ConclusionIn this passive cutaneous anaphylaxis model, ASA and alcohol affected both reaction time and size of reactions elicited after egg ingestion. This suggests that patients with egg allergy could have faster and more severe reactions during ASA treatment or under alcohol influence.

BSACI 2021 guideline for the management of egg allergy

This guideline advises on the management of patients with egg allergy. Most commonly egg allergy presents in infancy, with a prevalence of approximately 2% in children and 0.1% in adults. A clear clinical history will confirm the diagnosis in most cases. Investigation by measuring egg-specific IgE (by skin prick testing or specific IgE assay) is useful in moderate-severe cases or where there is diagnostic uncertainty. Following an acute allergic reaction, egg avoidance advice should be provided. Egg allergy usually resolves, and reintroduction can be achieved at home if reactions have been mild and there is no asthma. Patients with a history of severe reactions or asthma should have reintroduction guided by a specialist. All children with egg allergy should receive the MMR vaccine. Most adults and children with egg allergy can receive the influenza vaccine in primary care, unless they have had anaphylaxis to egg requiring intensive care support. Yellow Fever vaccines should only be considered in egg-allergic patients under the guidance of an allergy specialist. This guideline was prepared by the Standards of Care Committee (SOCC) of the British Society for Allergy and Clinical Immunology (BSACI) and is intended for allergists and others with a special interest in allergy. The recommendations are evidence based. Where evidence was lacking, consensus was reached by the panel of specialists on the committee. The document encompasses epidemiology, risk factors, diagnosis, treatment, prognosis and co-morbid associations.

Oral Immunotherapy in Patients with IgE Mediated Reactions to Egg White: A Clinical Trial Study

ABSTRACT Background Oral immunotherapy (OIT) is under consideration as a promising treatment for desensitization of egg-allergic patients. The objective of this study was to assess the effectiveness of egg-white OIT in patients with IgE-mediated allergy to egg white and to compare the clinical and laboratory findings before and after OIT. Methods This clinical trial was performed from February to August 2018 in Rasool e Akram Hospital, Tehran, Iran. Patients’ selection criteria included a history of allergic symptoms, skin prick test (SPT) reactivity to egg white, and the inability to pass the Oral Food Challenge (OFC). Egg-white OIT was done for eight patients in the OIT group for 6 months while egg-white-free products were administrated for controls. The SPT reactivity, specific IgE, and IgG4 for egg white and ovomucoid were evaluated before and after OIT. Results Hundred percent of the subjects in OIT group were desensitized and tolerated 40 cc raw egg white following 6-month maintenance whereas none of the controls was able to pass the OFC. The findings obtained from the evaluations indicated a significant decrease in the wheal size and specific IgE to egg white after OIT (P = .001). Furthermore, a significant decrease of IgE/IgG4 ratio to egg white was found in OIT group (P = .01). Conclusion This OIT protocol was successful as all OIT patients were able to continue 6-month OIT process and the reaction threshold to egg white increased in the OIT group. Therefore, it could be regarded as an effective and safe protocol to treat egg-allergic patients.

Mechanically deboned turkey meat with improved digestibility and biological value

AbstractEnzymatic hydrolysates of mechanically deboned meat (MDM) for a long time have been used as flavouring and functional food ingredients in the food industry and also as the bases of formula foods for special dietary uses.The aim of the present study was to produce MDM hypo-antigenic products with improved digestibility and high biological value to be used as a milk protein alternative. turkey MDM was treated with digestive enzymes (trypsin and/or α-chymotrypsin, or pancreatin), followed by freeze drying. The optimised reaction conditions of hydrolysis were at 6% (w/v) of meat protein in 0.1% NaHCO3 buffer, pH 7.5; pancreatin enzyme with 50 TAME units/g meat protein substrate, 37 °C and 60 min). Hydrolysates (MDMH) were assessed for degree of hydrolyses (DH, %) by using trinitrobenzenesulphonic acid method and MW distribution by SDS-PAGE. Modification of immune reactive binding sites in MDMHs was monitored by immunoblot with cow’s milk, chicken egg or meat allergic human patients’ sera. Biological value indices (True Digestibility (TD), Net Protein Utilisation (NPU), Biological Value (BV)) were determined using rat feeding trials. Among the MDMH products, the pancreatic hydrolysate proved to be the most favourable in terms of biological value and digestibility as well as hypoallergenic property.

Fish muscle processing into seafood products reduces β-parvalbumin allergenicity

Fish is one of the eight major foods causing type-I food allergy, and the prevalence of its allergy is increasing in part due to changes in consumption habits. One of the main drivers for these changes has been the processing developments transforming the fish muscle into seafood products. Most fish allergic patients react to the Ca2+-binding protein β-parvalbumin (β-PV) abundant in muscle. Here we have analyzed the effect of processing in the content and allergenic properties of the β-PV. We found that the transformation process decreases the β-PV content (4.7 ± 0.3 mg/g muscle, 0.24 ± 0.03 mg/g surimi, ≤0.003 ± 0.001 mg/g in seafood products), reduces the specific-IgE binding and prevents allergy relevant properties such the protease resistance and amyloid aggregation. These results suggest seafood products as potentially tolerable foods for fish allergic patients, but milk and egg allergic patients should be aware of the presence relevant additives.

Optimizing Patient Care in Egg Allergy Diagnosis and Treatment.

Egg allergy occurs frequently in childhood with a reported prevalence of 1.3–1.6%. Providing optimal care to egg-allergic patients requires knowledge of the most up-to-date developments in both diagnosis and management, as well as effective communication skills, which will engage the patient in the shared decision-making process. This review aims to provide up-to-date information on egg allergy and also serve as a concise guide on optimal patient diagnosis and management. The field of food allergy has seen multiple advances in recent years, including use of component resolved diagnostics, early egg introduction into the infant diet as a way of preventing egg allergy, baked egg introduction and oral immunotherapy as a form of active therapy. Faced with a variety of options and treatment paths, it is important to ensure that patients and families taking part in the decision-making process have fully understood the potential outcomes and trade-offs and can undertake a detailed discussion of all options that are available to them. Shared decision-making remains the cornerstone of optimal patient care.

Distinct Animal Food Allergens Form IgE-Binding Amyloids

Several animal food allergens assemble into amyloids under gastric-like environments. These aggregated structures provide Gad m 1 with an enhanced immunoglobulin E (IgE) interaction due to the fibrillation of the epitope regions. However, whether these properties are unique to Gad m 1 or shared by other food allergens has not yet been addressed. Using Bos d 5, Bos d 12 and Gal d 2 as allergen models and Gad m 1 as the control, aggregation reactions and the sera of milk, egg and fish allergic patients have been analyzed, assessing the IgE interactions of their amyloids. We found that amyloids formed by Bos d 12 and Gal d 2 full-length and truncated chains are recognized by the IgEs of milk and egg allergic patient sera. As with Gad m 1, in most cases amyloid recognition is higher than that of the native structure. Bos d 5 was not recognized under any fold by the IgE of the sera studied. These results suggest that the formation of IgE-binding amyloids could be a common feature to animal food allergens.

Safety of yellow fever vaccine administration in confirmed egg-allergic patients

Yellow fever vaccine (YFV) is recommended in endemic areas but represents a risk for egg-allergic patients, as it is cultivated in embryonated eggs. This study aims to describe the outcomes of yellow fever vaccination in patients with confirmed egg allergy (EA). Methods:A prospective study was conducted from January 2018 to September 2019. EA was diagnosed through positive oral food challenge (OFC), recent history of anaphylaxis following egg contact (anaphylaxis in the last 6 months) or immediate allergic reaction in the last 2 months with positive specific IgE. A skinprick test (SPT) with YFV was performed. If the SPT was negative, an intradermal test (ID) was performed at a 1:100 dilution. If the ID was negative, a full dose of YFV was administered. If the skin prick test or ID were positive, the YFV was administered using a graded dosing protocol. Results: It was included 58 patients with confirmed egg allergy (36 M:22F), with a median age of 2.3 years (0.7–13.9 y/o). Forty-two patients had a positive OFC. Nine reported recent anaphylaxis. The other 7 had reactions in the last 2 months with positive specific IgE. During OFC, 15 presented anaphylaxis, while the other 27 presented hives and/or angioedema or vomiting. SPT with YFV was negative in all patients. ID was negative in 48 patients who uneventfully received a full dose of YFV. Ten patients had a positive ID and received YFV in graded doses. Six patients presented a mild reaction controlled with antihistamines, and 4 patients received the vaccine without reactions. Positive ID was significantly related to the vaccine reaction (p < 0.0001). Administration of YFV using a specific protocol was safe even in anaphylactic patients. However, we recommend performing the ID, which can help predict a higher risk of vaccine reaction. An appropriate setting is required to control adverse events.