Anaphylaxis in children and adolescents: The European Anaphylaxis Registry.

BACKGROUND: Anaphylaxis in children and adolescents is a potentially life-threatening condition. Its heterogeneous clinical presentation and sudden occurrence in virtually any setting without warning have impeded a comprehensive description. OBJECTIVE: We sought to characterize severe allergic reactions in terms of elicitors, symptoms, emergency treatment, and long-term management in European children and adolescents. METHODS: The European Anaphylaxis Registry recorded details of anaphylaxis after referral for in-depth diagnosis and counseling to 1 of 90 tertiary allergy centers in 10 European countries, aiming to oversample the most severe reactions. Data were retrieved from medical records by using a multilanguage online form. RESULTS: Between July 2007 and March 2015, anaphylaxis was identified in 1970 patients younger than 18 years. Most incidents occurred in private homes (46%) and outdoors (19%). One third of the patients had experienced anaphylaxis previously. Food items were the most frequent trigger (66%), followed by insect venom (19%). Cow's milk and hen's egg were prevalent elicitors in the first 2 years, hazelnut and cashew in preschool-aged children, and peanut at all ages. There was a continuous shift from food- to insect venom- and drug-induced anaphylaxis up to age 10 years, and there were few changes thereafter. Vomiting and cough were prevalent symptoms in the first decade of life, and subjective symptoms (nausea, throat tightness, and dizziness) were prevalent later in life. Thirty percent of cases were lay treated, of which 10% were treated with an epinephrine autoinjector. The fraction of intramuscular epinephrine in professional emergency treatment increased from 12% in 2011 to 25% in 2014. Twenty-six (1.3%) patients were either admitted to the intensive care unit or had grade IV/fatal reactions. CONCLUSIONS: The European Anaphylaxis Registry confirmed food as the major elicitor of anaphylaxis in children, specifically hen's egg, cow's milk, and nuts. Reactions to insect venom were seen more in young adulthood. Intensive care unit admissions and grade IV/fatal reactions were rare. The registry will serve as a systematic foundation for a continuous description of this multiform condition.

[Contribution of epidemiology to the prevention of drug allergies]. / Contribution de la recherche épidémiologique à la prévention des allergies médicamenteuses.

Drug allergies are heterogeneous and multifactorial. They can be life-threatening and lead to market withdrawal of particularly risky drugs. Immunological research has improved our understanding of drug allergies but has not yet been able to prevent them. In contrast, epidemiological research not only provides information on the incidence and risk factors of such reactions, but can now, in conjunction the most recent immunological data, also help to prevent some of them. For example, prior pholcodine consumption has been shown to increase the risk of anaphylaxis due to neuromuscular blocking agents during general anesthesia. This review examines the place of interventional epidemiology in the field of drug allergy, taking as examples both myorelaxant-induced anaphylaxis and abacavir-induced DRESS.

Anaphylaxis to general anesthetics.

The incidence of hypersensitivity reactions to anesthetics is estimated 1 in 13,000 anesthetics up to 1 in 3,180. The rate of mortality ranges between 3 and 9%. 90% of reactions appear at anesthesia induction. Cardiovascular collapse and bronchospasm are more frequent in IgE-dependent reactions. The leading causes are neuromuscular blocking agents (50-70% of cases). IgE-dependent reactions are predominant. Previous sensitization by other compounds containing quaternary ions is suspected. Cross-reactions are frequent. Latex allergy is the second cause, followed by antibiotics and beta-lactams in general. The incidence of anaphylaxis to vital dyes and chlorhexidine increases. Anaphylaxis to intravenous hypnotics, plasma substitutes, aprotinin, protamine and other drugs can occur. Any suspected hypersensitivity reaction during anesthesia must be extensively investigated to confirm the nature of the reaction, to identify the responsible drug, to study cross-reactivity in cases of anaphylaxis to a neuromuscular blocking agent and to provide recommendations for future anesthetic procedures. Tryptase assay at the time of the reaction has to be implemented by thorough investigations carried out weeks later: prick tests and intradermal tests, quantification of specific IgE to compounds containing quaternary ammonium ions, histamine release test or cytometric analysis of basophile activation.

Gastrointestinal allergy in adults.

The prevalence of food allergy reaches 3% in the adult population. Chronic gastrointestinal allergy is a rare entity: 4.2% of food allergies in adults, and represents 3.2% of all intestinal disorders. Non-specific symptoms are the rule but eosinophilic gastrointestinal disorders are the subject of much interest. Endoscopy and biopsies of the gastrointestinal tract help the differential diagnoses. Food allergy is suspected from the patient's history leading to skin tests and laboratory tests identifying a sensitization but allergy is only confirmed by standardized challenges or eviction diets over a sufficiently long period. New types of investigations coupling oral challenges to foods to gastroenterological techniques should be studied further.