Hymenoptera venom allergy is a potentially life‐threatening allergic reaction following a honeybee, vespid, or ant sting. Systemic‐allergic sting reactions have been reported in up to 7.5% of adults and up to 3.4% of children. They can be mild and restricted to the skin or moderate to severe with a risk of life‐threatening anaphylaxis. Patients should carry an emergency kit containing an adrenaline autoinjector, H1‐antihistamines, and corticosteroids depending on the severity of their previous sting reaction(s). The only treatment to prevent further systemic sting reactions is venom immunotherapy. This guideline has been prepared by the European Academy of Allergy and Clinical Immunology's (EAACI) Taskforce on Venom Immunotherapy as part of the EAACI Guidelines on Allergen Immunotherapy initiative. The guideline aims to provide evidence‐based recommendations for the use of venom immunotherapy, has been informed by a formal systematic review and meta‐analysis and produced using the Appraisal of Guidelines for Research and Evaluation (AGREE II) approach. The process included representation from a range of stakeholders. Venom immunotherapy is indicated in venom‐allergic children and adults to prevent further moderate‐to‐severe systemic sting reactions. Venom immunotherapy is also recommended in adults with only generalized skin reactions as it results in significant improvements in quality of life compared to carrying an adrenaline autoinjector. This guideline aims to give practical advice on performing venom immunotherapy. Key sections cover general considerations before initiating venom immunotherapy, evidence‐based clinical recommendations, risk factors for adverse events and for relapse of systemic sting reaction, and a summary of gaps in the evidence.

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Mast cell activation (MCA) accompanies diverse physiologic and pathologic processes and is one of the more frequently encountered conditions in medicine. MCA-related symptoms are usually mild and often transient. In such cases, histamine receptor blockers and other mediator-targeting drugs can usually control MCA. In severe cases, a MCA syndrome (MCAS) may be diagnosed. However, overt MCAS is an unusual condition, and many patients referred because of suspected MCAS are diagnosed with other diseases (autoimmune, neoplastic, infectious) unrelated to MCA or suffer from MCA-related (e.g., allergic) disorders and/or co-morbidities without fulfilling criteria of an overt MCAS. These considerations are important as more and more patients are informed they may have MCA or even MCAS without completing a thorough medical evaluation. In fact, in several instances, symptoms are misinterpreted as MCA/MCAS, and other, clinically relevant conditions are not thoroughly pursued. The number of such referrals is increasing. In order to avoid such unnecessary referrals and to prevent misdiagnoses, we here propose a diagnostic algorithm through which a clinically relevant (systemic) MCA can be suspected and MCAS can subsequently be documented or excluded. In addition, the algorithm proposed should help guide the investigating care providers to consider the two principle diagnoses that may underlie MCAS, namely severe allergy and systemic mastocytosis accompanied by severe MCA. Although validation is required, we anticipate that this algorithm will facilitate the management of patients with suspected MCAS.

The FAQLQ-CF is the first self-administered disease-specific HRQL questionnaire for food-allergic children. This questionnaire has a strong internal consistency and cross-sectional validity. It discriminates between children who differ in number of food allergies, and it was short and easy to use in the population studied. Therefore, the FAQLQ-CF may be a useful tool in clinical research.

HRQL is impaired in food allergic adolescents and adults, compared to the general population, and it is intermediate in magnitude between DM and RA, asthma and IBS. Children show the least impact on generic HRQL from food allergy.

Background-The WHO classification separates mastocytosis into distinct variants, but prognostication remains a clinical challenge. The aim of this study was to improve prognostication for patients with mastocytosis. Methods-We analysed data of the registry of the European Competence Network on Mastocytosis including 1639 patients (age 17-90 years) diagnosed with mastocytosis according to Sperr et al.

The FAQLQ-AF is the first disease-specific HRQL questionnaire for food allergic adults and reflects the most important issues that food allergic patients have to face. The questionnaire is valid, reliable and discriminates between patients with different disease characteristics. The FAQLQ-AF is short and easy to use and may therefore be a useful tool in clinical research.

Mast cell activation syndrome (MCAS) is a condition characterized by recurrent episodes of clinically relevant, systemic, severe reactions to mast cell (MC)-derived mediators released in the context of anaphylaxis or another acute MC-related event. It is important to document MC involvement in these reactions in order to establish the diagnosis MCAS. The most specific and reliable marker of systemic MC activation is an acute and substantial event-related (transient) increase in the serum tryptase level over the individual’s baseline value. However, the baseline level of tryptase varies depending on the underlying disease and the genetic background. For example, an estimated 3–5% of healthy individuals exhibit duplications or multiple copies of the <i>TPSAB1</i> gene encoding for alpha-tryptase, and over 30% of all patients with myeloid neoplasms, including mastocytosis, have elevated basal tryptase levels. Therefore, it is of utmost importance to adjust the event-related diagnostic (MCAS-confirming) increase in tryptase over the individual baseline in a robust approach. To address this challenge, the 20% + 2 formula was proposed by the consensus group in 2012. Since then, this approach has been validated in clinical practice by independent groups and found to be sound. In the current article, we discuss the emerging importance and value of the 20% + 2 formula in clinical practice and its role as a criterion of severe systemic MC activation and MCAS.