Underwent Skin Testing Research Articles

True Rate of Allergy among Pediatric Inpatients with Penicillin Allergy Labels (TRIAL).

Penicillin allergy is a common drug allergy diagnosis in pediatric patients; however, upon appropriate allergy testing, many of these patients are found not to have a true allergy. For patients with a reported allergy, alternative antibiotics are prescribed, which are less effective, more toxic, or more expensive. There is a lack of data evaluating allergies in hospitalized children and comparing allergy assessments conducted by pediatric allergists and pharmacists. To estimate the percentage of pediatric patients admitted with reported penicillin allergy who did not have a true penicillin allergy. This single-centre prospective cohort study included inpatients between 6 months and 17 years of age, with a documented penicillin allergy, who were admitted to the general pediatric and oncology units of a tertiary care children's hospital between November 2019 and March 2023. The allergy history, evaluation, and risk categorization were performed by pharmacists. The history was reviewed with the allergist, and the patient was then referred, underwent skin testing, or received oral amoxicillin challenge with monitoring for 1 hour. Thirty patients were included, of whom 29 (97%) had delabelling of their penicillin allergy. Four patients (13%) had delabelling on the basis of history alone, without risk assessment. Twenty-five (83%) of the patients were assessed as having low risk; 24 of these had delabelling following oral challenge, and 1 did not complete the oral challenge because of transfer to another hospital. One patient (3%) was assessed as having moderate risk, with delabelling on the basis of results of skin testing and oral challenge. The pharmacist's and allergist's risk assessments were in agreement in 29 (97%) of the 30 cases. Pediatric patients, including those with oncologic malignancies, are often mislabelled as having a penicillin allergy. Pharmacists are able to accurately determine true allergy risk and delabel penicillin allergies for pediatric patients in the hospital setting.

Early testing and grade of the reaction are affecting factors of skin test positivity in β-Lactam allergies.

Background: β-Lactams are the most widely used antibiotic family in the world. Nevertheless, they also stand out as the primary culprits for inducing drug hypersensitivity reactions (HSR). Methods: Between May 2018 and March 2023, patients with suspected HSRs to β-lactams, who underwent skin tests (ST), were retrospectively screened. The determinants of allergenic penicillin (DAP) tests, which include penicillin minor and major determinants, clavulanic acid, and amoxicillin, along with ampicillin, sulbactam, the identified culprit drugs, and alternative cephalosporins, which include cefuroxime, ceftriaxone prick and/or intradermal tests, were administered. The analysis focused on identifying positive ST results and determining the true HSRs rates in this patient cohort. Results: Of the 147 patients, 78.9% (n = 116) were women and the median (minimum-maximum) age was 41 years (18-71 years). Mild HSRs (grades 1-2) were observed in 72.78% (n = 107), whereas 24.4% (n = 36) had severe reactions (grades 3-4) and 2.7% (n = 4) had an unknown grade. Of the patients, 64% (n = 94) experienced HSRs within the first hour after the last dose of the identified culprit drug. The overall positivity rate for all STs was 26.5% (n = 39). ST positivity rates were notably higher in individuals who had experienced HSRs within the past 6 months (p = 0.02) and those with severe anaphylaxis (p < 0.001). Conclusion: β-Lactam ST positivity is higher, especially in those with grades 3-4 reactions and consulted a physician within the first 6 months after their HSRs.

Evaluation of the passive mast cell activation test for identifying allergens in perioperative anaphylaxis: a study protocol for a prospective diagnostic accuracy study

IntroductionPerioperative anaphylaxis (POA) can lead to significant complications. Therefore, accurate identification of allergens for POA patients is critical to ensure the safety of future surgical and anaesthetic procedures. Existing perioperative...

Etoposide hypersensitivity reactions and outcomes of desensitizations in immediate-type hypersensitivity reactions

Aims: This study aims to define characteristics of hypersensitivity reactions with etoposide, and outcomes of desensitizations in immediate-type hypersensitivity rections&#x0D; Methods: This is a retrospective observational study of patients who had hypersensitivity reactions with etoposide from January 2019 to December 2023. &#x0D; Results: A total of 39 patients with lung cancer were included in the study. Ten (25.6%) patients had known other drug allergies and three (7.7%) patients had previous chemotherapeutic hypersensitivity two with paclitaxel and one with docetaxel. Most of the initial hypersensitivities were in the first or second cycle (n=29, 74.4%). Ten (25.4%) patients had hypersensitivity reactions at the first application of etoposide. Thirty (76.9%) patients had immediate-type hypersensitivity reactions. There was no significant difference in terms of patient and initial hypersensitivity characteristics between patients who had immediate or non-immediate type hypersensitivity reactions. Of the 30 patients with immediate-type hypersensitivity reactions, initial reaction was mild in 16 (53.3%) and moderate in 14 (46.7%) patients. Most common symptoms were erythema in 29 (96.7%), dyspnea in 13 (43.3%), chest tightness in 8 (26.7%), discomfortness in 7 (23.3%), and hypertension in 6 (20%). Skin tests were negative in five patients who underwent skin testing. A total of 98 desensitization courses were performed in 27 patients and 3 (11.1%) patients had breakthrough reactions.&#x0D; Conclusion: Most of the hypersensitivity reactions to etoposide are immediate-type and not severe. Desensitization is an effective and safe procedure to manage these reactions. Further research is needed to elucidate the mechanisms of hypersensitivity reactions.

One-Bag 8-Step Ferric Carboxymaltose Desensitization Protocol for Patients with a History of Hypersensitivity Reactions to Iron Preparations

Introduction: Iron deficiency is the most common cause of anemia in both sexes, although it is more common in women. Intravenous (IV) iron replacement is preferred in patients who cannot tolerate oral treatment or when iron stores need to be replenished rapidly. In this study, we wanted to share the ferric carboxymaltose (FCM) desensitization protocol that we self-created and successfully applied. Methods: This retrospective cross-sectional study included patients with a history of hypersensitivity reactions (HSRs) to IV or oral iron replacement and patients who were planned to receive IV iron replacement but were referred to the allergy clinic because of have risk factors (atopic diseases, history of HSR to other drugs, high serum tryptase levels, etc.) for HSRs. Before desensitization, some of the patients underwent skin tests (skin prick test and intradermal test) with FCM, and the results were recorded. Skin tests were not performed in patients with a history of drug use (antihistamine, systemic steroid, omalizumab, etc.) that affected the results of skin tests. All patients underwent a one-bag 8-step desensitization protocol with 500 mg FCM and were observed for 2 h after desensitization. Results: A total of 15 patients (14 females and 1 male) with a mean age of 41.13 ± 11.18 years were included in the study. When the patients were evaluated in terms of the risk of allergic reactions according to their clinical history, 8 patients had a history of anaphylaxis with iron preparations (FCM, n = 4; ferric hydroxide sucrose, n = 2; iron [II] glycine sulfate, n = 1; and iron [III] hydroxide polymaltose, n = 1), and 7 patients had a history of HSR other than anaphylaxis with iron preparations (urticaria, n = 6 [FCM, n = 2; iron (II) glycine sulfate, n = 2; and iron (III) hydroxide polymaltose, n = 2] and urticaria + angioedema [ferric hydroxide sucrose, n = 1]). Desensitization was successfully completed in all patients. No HSR was observed during or after the procedure in any of the patients. Conclusion: IV iron replacement is a very effective method, especially in cases where iron stores need to be replenished more rapidly. In patients with a history of iron HSR or at risk of developing HSR, replacement can be safely performed without an allergic reaction with successful desensitization protocols.

The Impact of the Pandemic on Cat and Dog Allergies.

The impact of the COVID-19 pandemic on allergic patients is not clearly understood. The aim of this study is to investigate the changes in sensitivity to cat and dog allergens in patients with respiratory allergies in Istanbul during the COVID-19 pandemic. Before the pandemic (March 2018 - March 2020) and during and after the pandemic (March 2020 - March 2022), a total of 5499 patients who underwent skin testing were retrospectively evaluated. The patients' age, gender, diagnosis, total IgE, and eosinophil values were recorded. Patients were divided into two groups: 2-6 years old and 7 years and older. The frequency of sensitization to cats and dogs was investigated in both groups before and after the pandemic. The median age of the 5499 children included in the study was 77 months, with a range of 2 to 221 months. Furthermore, 55.7% of the children were male. Of the children, 59.1% were examined before the pandemic, and 40.9% during and after the pandemic. During the examinations, allergic rhinitis was identified in 1628 children (29.6%), asthma in 1829 children (33.3%), and both asthma and allergic rhinitis in 2042 children (37.1%). Allergies to cats were found in 247 children (4.5%), and to dogs in 166 children (3.0%). When comparing the age groups, the frequency of cat allergy in the 7-years and older group was found to have decreased compared to the pre-pandemic period, and the statistical difference was close to significance (p=0.08). However, regarding dog allergy, in the 7 years and older group, the sensitivity to dogs, which was 5.6% before the pandemic, had decreased to 2.6% during the pandemic, and this decrease was found to be statistically highly significant (p<0.001). Environmental allergen exposure has a significant impact on the phenotype of allergic diseases. Changes in patients' lifestyles and increased time spent at home during the pandemic may have led to a decrease in contact with outdoor cat and dog allergens, resulting in a reduced frequency of cat and dog sensitivity. Additionally, the introduction of mask-distance-handwashing/disinfection rules during the pandemic is believed to have reduced contact with cat and dog allergens, potentially contributing to a decrease in allergy frequency.

Delabeling, safety, and impact of β-lactam allergy testing: Asystematic review.

To improve β-lactam delabeling outcomes, we need to understand current practice and the evidence base regarding its outcomes, safety, and impact. We sought to assess the existing published evidence reporting on the effectiveness of penicillin allergy testing and delabeling. We conducted a systematic review of studies reporting β-lactam delabeling practices and outcomes after testing, including β-lactam use and patient understanding of the delabeling result. Searches of the PubMed, Scopus, and Embase databases; clinical trial registries; and websites of professional organizations were conducted. Data were extracted from the included studies in duplicate, with a third extraction if discrepancies remained. We included 284 publications (covering 98,316 participants); 173 were prospective studies, with no randomized controlled trials. The overall study quality was low. In all, 95.6% of individuals who underwent provocation testing were delabeled. Factors associated with successful delabeling could not be determined because of significant heterogeneity between studies. Anaphylaxis due to testing occurred in 0.3% of participants (95 of 31,667). Subjects who did not undergo skin testing (6,980 patients in 31 studies) before challenge had higher rates of provocation test positivity (8.8% vs 4.1% [P< .0001]) and anaphylaxis (15.9% vs 2.7% [P< .0001]) than those subjects who underwent skin testing (51,607 patients in 177 studies). Six studies (2.1%) followed patients after testing to assess their adherence to prescribing recommendations. In all, 136 participants (20.6%) were actively avoiding β-lactams despite delabeling. The available data suggest that penicillin allergy testing is safe and effective in delabeling most individuals, but the evidence base is incomplete and more work is required to assess the role of skin testing and the impact that delabeling is having on prescribing habits.

Taxanes Hypersensitivity is not a risk factor for severe reactions to SARS-Cov-2 Vaccines.

Introduction. The main mechanism involved in hypersensitivity reactions (HSR) to Taxanes (primarily Paclitaxel and Docetaxel) seems to be a complement activation by their excipients: polyoxyethylated castor oil (Paclitaxel) and Polysorbate 80 (Docetaxel). SARS-CoV-2 vaccines contains Polysorbate 80 or polyethylene glycol (PEG) as excipients, which are structurally correlated to polyoxyethylated castor oil. The aim of this study was to verify the presence of a higher risk of HSR to SARS-CoV-2 vaccines in patients with history of HSR to taxanes. Methods. Patients with history of HSR to taxanes were evaluated before the vaccination in our center and underwent skin tests for PEG and Polysorbate 80 (P and P). Some patients completed the vaccination course in other centers without prior P and P skin tests because they had not manifested taxanes hypersensitivity before vaccination, or because those tests were not available. Results. A total of 50 patients were evaluated. 100% of patients with history of hypersensitivity to taxanes completed the vaccine course with no cases of anaphylaxis. 33 patients underwent skin tests for P and P before the vaccination and no correlation was found between P and P skin tests positivity and taxanes skin tests positivity (p = 0.538). 7 patients developed mild symptoms during skin tests and vaccination, similar but weaker than those suffered at the time of the taxane infusion, and independently from the results of skin tests (2/7 positive patients). Conclusions. In our cohort Patients with history of reaction to taxanes were not at higher risk to develop anaphylaxis to SARS-CoV-2 vaccines. However, a common non-IgE mediated mechanism behind those HSRs cannot be completely excluded. This can only account for mild and harmless symptoms in case of SARS-CoV-2 vaccines. Antihistamine premedication and longer observation after the vaccination are still prudent in these patients.

Hymenoptera venom skin testing: Adopting an accelerated test protocol

BackgroundThe standard method of Hymenoptera venom intradermal skin test is performed at a starting concentration of 0.001 to 0.01 μg/mL and increased by 10-fold concentrations until positive or a maximum concentration of 1 μg/mL. Accelerated methods that start at higher concentrations have been reported as safe; however, many institutions have not adopted this approach. ObjectiveTo compare the outcome and safety of standard and accelerated venom skin test protocols. MethodsThis was a retrospective chart review of patients with suspected venom allergy who underwent skin testing at 4 allergy clinics within a single health care system from 2012 to 2022. Demographic data, test protocol (standard vs accelerated), test results, and adverse reactions were reviewed. ResultsOf 134 patients who underwent standard venom skin test, 2 (1.5%) experienced an adverse reaction, whereas none of the 77 patients who underwent accelerated venom skin test experienced an adverse reaction. One patient, with a history of chronic urticaria, experienced urticaria. The other experienced anaphylaxis requiring an epinephrine although had tested negative to all venom concentrations. Within the standard testing protocol, more than 75% of the positive results occurred at concentrations of 0.1 or 1 μg/mL. Within the accelerated testing protocol, more than 60% of the positive results occurred at 1 μg/mL. ConclusionThe study underscores the overall safety of venom intradermal skin test. Most of the positive results occurred at 0.1 or 1 μg/mL. Adopting an accelerated approach would reduce time and cost associated with testing.

Perioperative anaphylactic reactions to central venous and pulmonary artery catheters containing chlorhexidine, sulfadiazine, or latex: a historical cohort study.

Central venous catheters (CVCs) and pulmonary artery catheters (PACs) containing chlorhexidine, silver sulfadiazine, or latex can cause perioperative anaphylaxis. We examined the incidence of and outcomes associated with anaphylaxis caused by CVCs/PACs. In a historical cohort study, we retrospectively identified adult patients fitted with CVCs/PACs at the Mayo Clinics in Minnesota, Arizona, and Florida from 1 January 2008 to 1 March 2018. Potential and confirmed cases of perioperative anaphylactic reactions were individually reviewed and classified. During the study period, 39,505 procedures were performed during which CVCs/PACs were inserted. Of these, 2,937 patients with pre-existing chlorhexidine, sulfonamide (sulfa), and/or latex allergies had CVCs/PACs inserted that contained these substances. Perioperative anaphylaxis, in which CVCs/PACs were the confirmed or potential causative agent, occurred during 53 procedures. Seven patients had a preoperatively reported sulfa or latex allergy; no patients had a preoperative chlorhexidine allergy. Six of the seven patients with reported allergies to sulfa or latex had a CVC/PAC inserted that contained these substances. Twenty-four patients with anaphylaxis had postoperative allergic disease consultation; ten of these (42%) underwent skin testing. Perioperative anaphylactic reactions related to CVCs/PACs containing chlorhexidine, silver sulfadiazine, or latex were rare in this large historical cohort study. We identified 2,937 patients with pre-existing chlorhexidine, sulfa, and/or latex allergies and had CVCs/PACs inserted that contained these substances. Although few cases of perioperative anaphylaxis attributable to these substances were observed in patients with corresponding allergies, the potential for substantial complication exists. Providers should be aware of the potential for these hidden exposures.

Clavulanic Acid Is a Leading Culprit Beta-Lactam in Immediate Allergic Reactions to Penicillins.

Clavulanate, a beta-lactam associated with amoxicillin, is frequently prescribed in patients at all ages. Recent data implicate amoxicillin-clavulanate in up to 80% of beta-lactam allergy cases. We assessed clavulanate's role in inducing allergic reactions to this combination treatment, with a focus on selective immediate reactions. Adults (≥ 16 years) reporting a history of immediate reactions to amoxicillin-clavulanate were evaluated through a beta-lactam allergological workup, using modified European Academy of Allergy and Clinical Immunology guidelines. Patients first underwent skin testing, and if negative, drug provocation tests. Expected outcomes were: Group A, subjects with immediate reaction to classical penicillin group determinants (penicilloyl polylysine, minor determinants mixture, and/or penicillin G); Group B, subjects with selective immediate reaction to amoxicillin; Group C, subjects with selective immediate reaction to clavulanate and Group D, those immediate reactions with co-sensitization to clavulanate plus penicillin group determinants or amoxicillin. Of 1,170 included patients, 104 had immediate reactions: 36.5% to penicillin group determinants (Group A), 26.9% to amoxicillin (Group B), 32.7% to clavulanate (Group C), and 3.8% to clavulanate plus penicillin determinants or amoxicillin (Group D). Diagnosis was made by skin testing in 79%, 75% and 47% of the patients, respectively, in the first 3 groups (P < 0.001). Drug provocation tests were necessary to establish most other diagnoses. Anaphylaxis predominated over urticaria/angioedema in all groups. Selective immediate reactions to clavulanate accounted for over a third of cases with confirmed reactions after amoxicillin-clavulanate intake, with more than half experiencing anaphylaxis. Within this group, skin test sensitivity was below 50%. People taking amoxicillin-clavulanate may also be co-sensitized to both drugs.

A CASE OF INTRA-OPERATIVE ANAPHYLAXIS TO LATEX IN A PULMONARY ARTERY CATHETER

<h3>Introduction</h3> Perioperative anaphylaxis (POA) is a diagnostic challenge. We present a case of anaphylaxis to intravascular latex preceding aortic surgery. <h3>Case Description</h3> A 55-year-old man was admitted for aortic arch and valve repair. Upon insertion of a pulmonary artery (PA) catheter, he developed hypotension, hypoxemia with elevated airway pressures, and a non-urticarial rash without angioedema. Anaphylaxis was successfully treated with epinephrine, but surgery was canceled. The plasma tryptase levels were 15.8, 20.1, and 5.1 mcg/L at 40 minutes, 6 hours, and 10 days after the event, respectively. Eight weeks later, patient underwent skin testing with negative results to all perioperative medications and latex. Subsequent serum IgE-specific antigen testing was positive for latex and borderline positive for pholcodine, a surrogate for neuromuscular blocking agents (NMBAs). IgE was negative for morphine which argues against rocuronium-related anaphylaxis. Subsequent surgery was successful in a latex-free OR without NMBAs. The patient denied symptoms to latex balloons, condoms, or band-aids. <h3>Discussion</h3> The NAP6 reported zero confirmed latex-related anaphylaxis cases, likely due to decreased latex-use in the OR. Despite this decreased incidence, clinicians should continue to be aware of latex anaphylaxis. Latex exposures may not be apparent as in our patient who reacted to the balloon of a PA catheter. Our case adds to the five reported cases of anaphylaxis due to latex in a PA catheter balloon, all in patients with no previous history of latex allergy. The lack of standardized skin testing adds to the diagnostic complexity. We recommend both skin testing and IgE immunoCAPS in cases of POA.

IMMUNIZATION STRESS-RELATED RESPONSES DURING SKIN TESTING AND CHALLENGE TO COVID-19 VACCINES: A CASE SERIES

<h3>Introduction</h3> While IgE-mediated hypersensitivity to COVID-19 vaccines may occur, many adverse reactions (ARs) to COVID-19 vaccination are non-immunologic in nature and meet criteria for immunization stress-related response (ISRR). <h3>Methods</h3> Patients were referred to our allergy clinic for skin testing (prick with undiluted vaccine, intradermal with 1:100, 1:10, and undiluted vaccine) and graded challenge with COVID-19 vaccines (Pfizer, Moderna, or Johnson and Johnson) between July 2021 and June 2022. ARs were documented and treated accordingly. ARs were characterized as ISRR based on the World Health Organization diagnostic criteria or non-ISRR if symptoms were outside those criteria. <h3>Results</h3> 83 patients underwent skin testing (ST) and/or graded challenge (GC) with COVID-19 vaccines in our office. Twenty-six (31.3%) patients had one or more symptoms of AR in the immediate period following ST/GC while 57 patients completed vaccination without any AR. 15 patients (1 to ST, 14 to challenge dose) had symptoms consistent with ISRR. 14 of these patients completed full vaccine dose. No patients had any significant objective changes in physical exam. 11 patients had ARs not meeting ISRR criteria. The most reported symptom in this cohort was subjective pruritus. 6 of these patients were able to complete full vaccination dose. <h3>Conclusion</h3> Most patients with AR consistent with ISRR successfully completed full COVID-19 vaccine administration. Some patients with symptoms suggestive of histamine-mediated reaction had no objective findings and were also able to complete vaccination. Our experience highlights the need to consider ISRR in evaluation of vaccine reactions and supports the safety of COVID-19 vaccination in patients with ISRR.

Quantitative evaluation of sensitive skin by ANTERA 3D® combined with GPSkin Barrier®.

At present, there are many different evaluation methods for sensitive skin, including subjective, semisubjective, and objective evaluation. Various objective tests focus on assessing changes in barrier functions. It is anticipated that the ANTERA 3D®, in combination with GPSkin Barrier®, will provide better evaluation of sensitive skin. A total of 20 subjects with sensitive skin and 20 healthy participants were recruited. Sensitive skin subjects were treated with an anti-sensitive moisturizing tolerance-extreme cream which has anti-inflammatory and moisturizing effects, twice daily on the whole face for 28 days. VISIA® Skin Detector was used to record clinical images and red area. GPSkin Barrier® was used to measure TEWL and SCH. Texture, hemoglobin, and influenced area (mm2 ) were recorded using ANTERA 3D® . Subjects underwent skin tests and recorded changes at D0 and D28. Data were only collected from healthy participants who did not receive treatment as controls. TEWL, texture, hemoglobin, and affected area in sensitive skin group were significantly higher than those in healthy group, while SCH was significantly lower than that in healthy group (p all<0.05). After anti-inflammatory and moisturizing treatment, the texture, hemoglobin, and affected area of sensitive skin decreased, TEWL decreased while SCH increased (p all<0.05). Based on the results, the combination of the ANTERA 3D® with GPSkin Barrier® could be used as a new kind of quantitative evaluation method for the detection and diagnosis of sensitive skin.

Do cross-food allergies to propofol exist?

Propofol is a short and rapidly acting intravenous anesthetic extensively used for the induction and maintenance of general anesthesia. It is a lipid emulsion that contains soybean oil, purified egg phosphatide, and egg lecithin. Therefore, the package leaflet indicates that its administration is contraindicated in patients allergic to soy, eggs, or peanuts. Our study aimed to determine whether patients with proven food allergies are allergic to propofol. Patients of all ages allergic to soy, eggs, or peanuts who agreed to undergo skin testing for propofol allergies were included. The subjects first underwent a skin test to confirm food allergies. If candidates were negative, they were excluded. If the result was positive, a propofol skin test was performed. Sixty-four patients with confirmed food allergies underwent a propofol skin test. Only one was positive in the propofol skin test (1.6%). The patient was allergic to peanuts and soybeans. These results reinforce the idea that there is no justification for avoiding propofol use in these subjects. Propofol can be safely administered to patients allergic to soy, eggs, or peanuts. We recommend caution in patients with a history of anaphylaxis after ingestion of the above-mentioned foods.

Mollusk allergy in shrimp-allergic patients: Still a complex diagnosis. An Italian real-life cross-sectional multicenter study

IntroductionShellfish allergy is an important cause of food allergies worldwide. Both in vivo and in vitro diagnostics failure nowadays is caused by the poor quality of the extracts associated with the scarce availability of allergenic molecules in the market. It is known that not all patients with shellfish allergies experience adverse reactions to mollusks. It is still unclear how to detect and diagnose these patients correctly. AimTo investigate the features of shrimp-allergic patients either reactive or tolerant to mollusks, with the currently available diagnostic methods. MethodsNineteen centers, scattered throughout Italy, participated in the real-life study, enrolling patients allergic to shrimp with or without associated reactions to mollusks. Patients underwent skin tests using commercial extracts or fresh raw and cooked shrimp and mollusks, and IgE reactivity to currently available allergenic extracts and molecules was measured in vitro. ResultsTwo hundred and forty-seven individuals with a self reported adverse reactions to shrimp participated in the study; of these 47.8% reported an adverse reaction to mollusks ingestion (cephalopod and/or bivalve). Neither of the tests used, in vivo nor in vitro, was able to detect all selected patients. Accordingly, a great heterogeneity of results was observed: in vivo and in vitro tests agreed in 52% and 62% of cases. Skin tests were able to identify the mollusk reactors (p < 0.001), also using fresh cooked or raw food (p < 0.001). The reactivity profile of mollusk reactors was dominated by Pen m 1, over Pen m 2 and Pen m 4 compared to tolerant subjects, but 33% of patients were not detected by any of the available molecules. Overall, a higher frequency of IgE rectivity to shrimp was recorded in northern Italy, while mollusk reactivity was more frequent in the center-south. ConclusionThe current diagnostic methods are inadequate to predict the cross-reactivity between crustaceans and mollusks. The detection of mollusks hypersensitivity should still rely on skin tests with fresh material. The exclusion of mollusks from shrimp allergic patients’ diets should occur when clinical history, available diagnostic instruments, and/or tolerance tests support such a decision.

Assessment of Immediate Allergic Reactions After Immunization With the Pfizer BNT162b2 Vaccine Using Intradermal Skin Testing With the COVID-19 Vaccines

BackgroundAllergic reactions to the coronavirus disease 2019 (COVID-19) vaccines have raised concerns, particularly as repeated doses are required. Skin tests with the vaccines excipient were found to be of low value, whereas the utility of skin tests with the whole vaccine is yet to be determined.ObjectiveTo evaluate a panel of skin tests and the outcomes of subsequent doses of immunization among subjects who suffered an immediate allergic reaction to the BioNTech (BNT162b2) COVID-19 vaccine.MethodsBetween March and December 2021, patients who experienced symptoms consistent with immediate allergic reactions to the BNT162b2 vaccine and were referred to the Sheba Medical Center underwent skin testing with polyethylene glyol (PEG)-containing medicines, Pfizer-BNT162b2, and Oxford–AstraZeneca vaccine (AZD1222). Further immunization was performed accordingly and under medical observation.ResultsA total of 51 patients underwent skin testing for suspected allergy to the COVID vaccines, of which 38 of 51 (74.5%) were nonreactive, 7 of 51(13.7%) had no skin sensitization but suffered a clinical reaction during skin testing (mainly cough), and 6 of 51 (11.7%) exhibited immediate skin sensitization. Both skin sensitization and cough during testing were related to a higher use of adrenaline following immunization (P = .08 and P = .024, respectively). Further immunization with the BNT162b2 vaccine was recommended unless sensitization or severe reaction to previous immunization was evident. The latter were referred to be tested/receive the alternative AZD1222 vaccine. Ten patients underwent skin testing with AZD1222: 2 of 10 (20%) demonstrated skin sensitization to both vaccines; thus, 8 of 10 were immunized with the AZD1222, of which 2 of 8 (25%) had allergic reactions.ConclusionsImmediate allergic reactions to COVID-19 vaccines are rare but can be severe and reoccur. Intradermal testing with the whole vaccine may discriminate sensitized subjects, detect cross-sensitization between vaccines, and enable estimation of patients at higher risk.

Vaccination counseling with and without excipient skin testing in patients with suspected allergic reactions to mRNA COVID-19 vaccines and patients with atopy.

BackgroundAllergic reactions have been reported with mRNA vaccines for COVID-19 prevention. Patients perceived to be at higher risk for a reaction may be referred to an allergist, although evaluation strategies may differ between allergists.ObjectiveOur aim was to determine outcomes of COVID-19 vaccinations in patients evaluated by an allergist using different approaches.MethodsWe conducted a retrospective case series evaluation of 98 patients seen at the University of Michigan Allergy Clinic for concerns regarding COVID-19 vaccination. Of these 98 patients, 34 underwent skin testing with polyethylene glycol (PEG) 2000 with or without PEG 3350/polysorbate 80 testing.ResultsOf the 34 patients on whom skin testing was performed, 16 underwent testing before vaccination and 18 underwent testing after a reported vaccine-related event. One patient had a positive skin testing result in response to PEG 3350 following a vaccination reaction and natural infection and was advised against a second dose. One patient with a significant history concerning of anaphylaxis in response to PEG had positive results of testing to identify allergy to PEG 2000, PEG 3350, and polysorbate 80 and was advised against vaccination. Of the 98 patients, 63 (64%) tolerated COVID-19 vaccination without complication after evaluation by an allergist.ConclusionNo significant differences were found between vaccination counseling with and without skin testing to excipients. Patients who presented before the first dose of vaccination were more likely to proceed with COVID-19 vaccination and tolerate vaccination without complication.

Revaccination and Adverse Event Recurrence in Patients with Adverse Events following Immunization

To estimate the risk of recurrence of adverse events following immunization (AEFIs) upon revaccination and to determine among patients with suspected vaccine allergy whether allergy skin test positivity was associated with AEFI recurrence. This prospective observational study included patients assessed in the Canadian Special Immunization Clinic Network from 2013 to 2019 with AEFIs who required revaccination with the vaccine temporally associated with their AEFI. Participants underwent standardized assessment and data collection. Special Immunization Clinic physicians used guidelines to inform their recommendations. Participants were followed up after revaccination to capture AEFI recurrences. Data were transferred to a central database for descriptive analysis. Overall, 588 participants were assessed for 627 AEFIs; 570 (91%) AEFIs occurred in children <18years of age. AEFIs included immediate hypersensitivity (130/627; 21%), large local reactions (110/627; 18%), nonurticarial rash (51/627; 8%), seizures (26/627; 4%), and thrombocytopenia (11/627; 2%). Revaccination was recommended to 513 of 588 (87%) participants. Among participants recommended and due for revaccination during the study period, 63% (299/477) were revaccinated. AEFI recurrence was 10% (31/299) overall, 31% (15/49) for large local reactions, and 7% (5/66) for immediate hypersensitivity. No recurrence was serious. Among 92 participants with suspected vaccine allergy who underwent skin testing and were revaccinated, the negative predictive value of skin testing for AEFI recurrence was 96% (95% CI 92.5%-99.5%). Most individuals with AEFIs were safely revaccinated. Among those with suspected vaccine allergy, skin testing may help determine the safety of revaccination.

Skin Tests for the Exploration of Hypersensitivity Reactions Associated with Iodinated Contrast Media.

Iodinated contrast media (ICM) are responsible for multiple side effects, especially hypersensitivity reactions. These reactions can either be authentic allergies or non-allergic hypersensitivity reactions. Skin tests (prick and intradermal tests) are simple to perform and can be of great help, especially if the ICM needs to be re-used. The aim of the study was to assess the characteristics of the patients in whom skin tests were performed and the results of these tests. This is a retrospective study from June 2014 to June 2019. All included patients had at least one episode of hypersensitivity reaction to ICM and underwent skin tests. We included 35 patients aged 18 to 85 years. The iopromide was the most implicated ICM. The reactions were mainly cutaneous (n=30) and immediate (n=27). The skin tests were negative, except for two patients. The re-use of ICM occurred in 11 patients: 9 with an ICM other than the one suspected and two patients with the same ICM. Among these patients, 5 did not have any premedication. Two of them had a second hypersensitivity reaction, the first with another ICM and the second with the same ICM. One of the main pillars of allergic exploration is ICM skin testing, not only to prevent a recurrence, but also to allow patients to benefit from ICM re-use, which are sometimes essential.