Teicoplanin is now increasingly used as a first-line prophylactic therapy for major surgical procedures, treatment of methicillin-resistant Staphylococcus aureus infections, and for those with reported penicillin allergy. Teicoplanin is rarely associated with anaphylaxis and there is limited information on the prevalence of teicoplanin- induced perioperative anaphylaxis. Here, we describe a case of a 12-year-old child with teicoplanin anaphylaxis peri-operatively.

Elevated levels of immunoglobulin E (IgE) are associated with allergies and other immunological disorders. Experimentally, sensitization with alum adjuvant favors IgE production while CpG-ODN adjuvant, a synthetic toll-like receptor 9 (TLR9) agonist, inhibits it. The cellular mechanisms underlying TLR-regulation of immunoglobulin production are still controversial. Specifically, TLR-mediated IgE regulation in vivo is not yet known. We show that augmented levels of IgE induced by sensitizations to OVA with or without alum adjuvant or with OVA-pulsed dendritic cells (DCs) were inhibited when sensitization to OVA was performed in the presence of CpG. Notably, CpG-mediated suppression of IgE production required MyD88-expression on DCs but not on B-cells. This contrasts with previous reports of in vitro regulation IgE where CpG acted directly on B cells via MyD88 pathway. In addition, CpG also inhibited IgE production in a MyD88-dependent manner when sensitization was performed with OVA-pulsed DCs. Finally, CpG signaling through MyD88 pathway was also necessary and sufficient to prevent anaphylactic antibody production involved in active cutaneous anaphylaxis.

Background and Objectives: Peanut allergy is the most common single cause of anaphylaxis in children. The risk factors for anaphylaxis in children with peanut allergy are not well defined. Therefore, we aimed to identify epidemiological, clinical and laboratory characteristics of children with peanut allergy that may predict the severity of allergic reaction and anaphylaxis. Materials and Methods: We conducted a cross-sectional study and included 94 children with peanut allergy. Allergy testing was performed, including skin prick testing and determination of specific IgE levels to peanut and its Ara h2 component. In case of discordance between patient history and allergy testing, an oral food challenge with peanut was performed. Results: Anaphylaxis, moderate and mild reactions to peanuts occurred in 33 (35.1%), 30 (31.9%) and 31 (33.0%) patients, respectively. The severity of the allergic reaction only weakly correlated (p = 0.04) with the amount of peanuts consumed. The median number of allergic reactions to peanut was 2 in children with anaphylaxis compared with 1 in other patients (p = 0.04). The median level of specific IgE to Ara h2 was 5.3 IU/ml in children with anaphylaxis compared to 0.6 IU/ml and 10.3 IU/ml in children with mild and moderate peanut allergy (p = 0.06). The optimal cutoff for distinguishing between anaphylaxis and a less severe allergic reaction to peanut was a specific IgE Ara h2 level of 0.92 IU/ml with 90% sensitivity and 47.5% specificity for predicting anaphylaxis (p = 0.04). Conclusions: Epidemiological and clinical characteristics of the patient cannot predict the severity of allergic reaction to peanut in children. Even standard allergy testing, including component diagnostics, is a relatively poor predictor of the severity of allergic reaction to peanuts. Therefore, more accurate predictive models including new diagnostic tools are needed to reduce the need for oral food challenge in most patients.

Hymenoptera allergens are the main triggers for anaphylaxis in susceptible dogs and humans. Hymenoptera venom specific immunotherapy (VIT), the only disease-modifying treatment, has the potential to prevent future life-threatening reactions in human patients. Prospective clinical data on VIT efficacy in dogs are currently lacking. Therefore, the aim of this study was to show that VIT is not only safe but also efficacious in preventing anaphylaxis in dogs allergic to Hymenoptera. This uncontrolled prospective clinical trial included 10 client-owned dogs with a history of anaphylaxis following repeated Hymenoptera stings. The sensitization to bee and wasp allergens was demonstrated by intradermal testing (IDT) and allergen-specific IgE serology. For VIT induction (induction phase), dogs received a shortened rush immunotherapy protocol with aqueous allergens, which was then followed by monthly injections of 100 g of alum-precipitated allergen (maintenance phase). VIT efficacy was determined by observing patients’ clinical reactions to re-stings. No systemic adverse events were seen during the induction and maintenance phase. From the seven re-stung dogs, only one developed a mild angioedema at the site of the sting; the remaining dogs were asymptomatic. These results show that VIT represents a safe and effective treatment option for Hymenoptera-allergic dogs.

Management of tumor lysis syndrome (TLS) associated with cancer chemotherapy for malignant tumors is important because of its potentially fatal course. The use of rasburicase, a recombinant urate oxidase, is recommended for TLS; however, because rasburicase is an enzymatic drug, one should be cautious of anaphylaxis during administration. Using claims data in Japan, we investigated the rate of rasburicase re-administration and the occurrence of anaphylaxis during re-administration in patients with hematopoietic malignancies in a multicenter setting. Re-administration of rasburicase was defined as administration after an interval of 21 days from the first dose. Of 373 patients, 18 were re-administered with rasburicase (re-administration rate: 4.8%). No patient developed anaphylaxis. The median number of days from the first to the last dose of rasburicase was 256.5 days (interquartile range: 138.8–455.8 days). The median daily dose was 7.5 mg (4.5–11.3 mg), and the median total dose was 33.8 mg (19.1–64.1 mg). This claims database analysis revealed that the re-administration rate of rasburicase was low in Japanese patients with hematopoietic malignancies, suggesting that rasburicase was being used appropriately, and that associated anaphylaxis was not observed.

The prevalence of food allergy has increased in recent years, especially in children. Food allergen avoidance and symptomatic drugs in case of an allergic reaction remain the standard of care in food allergy. Nevertheless, increasing attention has been given to the possibility to treat food allergy, through immunotherapy, particularly oral immunotherapy (OIT). Several OIT protocols and clinical trials have been published. Most of them focus on children allergic to milk, egg, or peanuts, although recent studies developed protocols for other foods, such as wheat and different nuts. OIT efficacy in randomized controlled trials is usually evaluated as the possibility for patients to achieve desensitization, while the issue of a possible long-term sustained unresponsiveness has not been completely addressed. Here, we evaluated current OIT knowledge, focusing on the results of clinical trials and current guidelines. Specifically, we wanted to highlight what is known in terms of OIT efficacy and effectiveness, safety, and impact on quality of life. For each aspect, we reported the pros and the cons, inferable from published literature. In conclusion, even though many protocols, reviews and meta-analysis have been published on this topic, OIT remains a controversial therapy and no definitive generalized conclusion may be drawn so far. It should be an option provided by specialized teams, when both patients and their families are prone to adhere to the proposed protocol. Efficacy, long-term effectiveness, possible role of adjuvant therapies, risk of severe reactions including anaphylaxis or eosinophilic esophagitis, and impact on the quality of life of both children and caregivers are all aspects that should be discussed before starting OIT. Future studies are needed to provide firm clinical and scientific evidence, which should also consider patient reported outcomes.

Mastocytosis is characterized by pathological accumulation of mast cells (MC) in various organs. In these patients, MC may degranulate and thereby contribute to clinical symptoms, especially when a concomitant allergy is present. However, MC activation can not only be induced by high-affinity receptors for IgE, but also by anaphylatoxins, neuropeptides, IgG immune complexes, complement-components, drugs, products of bacteria or parasites, as well as physical factors such as heat, cold, vibration, stress, sun, or physical effort. Symptoms due to mediators released by activated MC may develop in adults suffering from systemic mastocytosis, but also evolve in children who usually have cutaneous mastocytosis (CM). Clinically, CM is otherwise characterized by typical brown, maculopapular skin lesions or mastocytoma associated with a positive Darier’s sign. Pruritus and flushing are common and blistering may also be recorded, especially in diffuse CM (DCM). Pediatric patients with mastocytosis may also have gastrointestinal, respiratory, and neurologic complaints. Although anaphylaxis is not a typical finding, pediatric patients with massive skin involvement and high tryptase levels have a relatively high risk to develop anaphylaxis. This paper reviews MC mediator-related symptoms and anaphylaxis in children with mastocytosis, with special emphasis on risk factors, triggers, and management.

The Kounis syndrome (KS) is an acute coronary syndrome triggered by allergic or hypersensitiv-ity reactions. Incidence rates vary, with studies reporting 19.4 per 100.000 among all admissions and 3.4% among allergy patients. This review explores the expanding understanding of KS, en-compassing various manifestations, and focusing on both clinical data and forensic findings useful in performing the diagnosis. The pathophysiology of this syndrome involves a complex in-terplay between allergic reactions and the cardiovascular system. Mast cell activation, histamine release, leukotrienes, cytokines, and platelet activation can contribute to the coronary events. A classification system with three types (Allergic Angina, Allergic Myocardial Infarction, Allergic Stent Thrombosis) aids in categorizing presentations. The diagnosis of KS relies on clinical presentation, laboratory findings and imaging. Post mortem assessment of KS is based on the in-tegration of circumstantial data, autopsy and histological findings. Biochemical and immuno-histochemical analyses also contribute to post-mortem diagnosis. In conclusion, a combined, multidisciplinary approach, should be gained to ease diagnostic pro-cess which is crucial for forensic practitioners in confirming KS occurrence.

(1) Background: National health system databases represent one of the most obvious sources of information about epidemiology of adverse drug reactions including drug-induced allergy and anaphylaxis. (2) Methods: Retrospective analysis of data from national database of pharmacovigilance in the Russian Federation (analyzed period 02.04.2019 - 21.06.2023) was performed. The prevalence of anaphylactic reactions (ARs) was determined, the structure of drugs involved was estimated together with patients’ characteristics. (3) Results: ARs were reported in 8.3% of drug-induced allergic reactions (2304/27,727), mean age of patients was 48.2 ± 15.8 years, 53.2% were females. Main causative groups of drugs were antibiotics, ABs (44.62%), local anesthetics, (19.97%), and cyclooxygenase (COX)-inhibitors (10.07%). Fatal ARs was reported in 9.5% (218/2304), mean age 48.0 ± 16.7 years, 56.2% females. Pediatric population accounted for 5.8% (133/2304), mean age 11.8± 4.5 years, 51.9% females. Elderly population accounted for 2.8% (65/2304), mean age 73.0±5.3 years, 43.5% (27/65) females. ABs were the leading causative groups of ARs in the elderly (40%), children (42.86%), and among fatal cases (50%). (4) Conclusions: ARs accounted for 8.3% of all drug-induced allergic reactions, and ABs were the most common causative agents. Females predominated in all groups except elderly patients.

Recent evidence has highlighted the critical role of memory cells in maintaining lifelong food allergies, thereby identifying these cells as therapeutic targets. IgG⁺ memory B cells replenish pools of IgE-secreting cells upon allergen exposure, which contract thereafter due to the short lifespan of tightly regulated IgE-expressing cells. Advances in the detection and highly dimensional analysis of allergen-specific B and T cells from allergic patients have provided insight on their phenotype and function. The newly identified Th2A and Tfh13 populations represent a leap in our understanding of allergen-specific T cell phenotypes, though how these populations contribute to IgE memory responses remains poorly understood. Within, we discuss the mechanisms by which memory B and T cells are activated, integrating knowledge from human systems and fundamental research. We then focus on memory reactivation; specifically, on the pathways of secondary IgE responses. Throughout, we identify areas of future research which will help identify immunotargets for a transformative therapy for food allergy.

Background: The Coronavirus Disease 2019 (COVID-19) pandemic presented a new challenge in modern medicine. The development of vaccines was followed by massive population vaccinations. A few reports on post-vaccination allergic reactions have made patients and medical personnel uneasy as to anti-COVID-19 vaccines’ allergising potential. Most of the studies in this area to date have been small, and some that were based on global databases skipped most of the allergic diseases and concentrated only on anaphylaxis. We aimed to analyse the incidence of serious allergic reactions based on the EudraVigilance (EV) database, regardless of the reported symptoms and allergy mechanism. Methods: The total number of administrated vaccine doses was extracted on the 5th October 2023 from Vaccine Tracker and included all administrations since vaccinations began in the European Economic Area (EEA). Data on serious allergic reactions to COVID-19 vaccines was extracted from the EudraVigilance database with the same time point. The code names of 147 allergic symptoms or diseases were used. Results: The frequency of serious allergic reactions per 100,000 administered vaccine doses was 1.53 for Comirnaty, 2.16 for Spikevax, 88.6 for Vaxzevria, 2.11 for Janssen, 7.9 for Novavax, 13.3 for VidPrevtyn Beta and 3.1 for Valneva. The most prevalent reported reactions were oedema (0.46) and anaphylaxis (0.40). Only 6% of these reactions were delayed hypersensitivity-oriented. Conclusions: The overall frequency of potential serious allergic reactions to COVID-19 is very rare. Therefore, COVID-19 vaccines seem to be safe for human use. The lowest frequency of allergic reaction was observed for Comirnaty and the highest for Vaxzevria.

Our knowledge of biology and mast cell (MC) function, as well as disorders associated with the pathologic activation of MCs has been evolving over the last few decades. Anaphylaxis, mast cell activation syndrome (MCAS) and mastocytosis are interrelated yet distinct conditions within the spectrum of mast cell activation disorders. Nevertheless, all three conditions can co-exist in one and same patient, as pathologic MC activation is the key finding in all three. When mediator release is excessive and involves multiple systems, anaphylaxis and MCAS may occur. Furthermore, mastocytosis is a clonal disorder of MCs and often presents with anaphylaxis and MCAS. Nevertheless, in some cases even proliferative and accumulative features of MCs in mastocytosis can account for symptoms and disease progression. In each case, diagnosis can be only made when diagnostic consensus criteria are fulfilled. The current article aims to provide a concise clinical update and pinpoint main difficulties in diagnosing these puzzling disorders of MCs in medical practice.