Perioperative hypersensitivity reactions constitute a first-line problem for anesthesiologists and allergists, so it is advisable that hospitals have a consensus protocol for the diagnosis and management of these reactions. However, this kind of protocols is not present in many hospitals, leading to problems in treatment, the communication of incidents and subsequent etiological diagnosis. In this document we present a systematic review of the available scientific evidence and provide general guidelines for the management of acute episodes and Resumen:Las reacciones de hipersensibilidad perioperatorias constituyen un problema de primera línea para los anestesiólogos y alergólogos, por lo que es recomendable que los hospitales tengan un protocolo de consenso para el diagnóstico y el tratamiento de estas reacciones. Sin embargo, este tipo de protocolos no está presente en muchos hospitales, lo que conlleva problemas en el tratamiento, la comunicación de incidentes y el posterior diagnóstico etiológico. Este documento ha sido creado por miembros del Comité de Alergia a Medicamentos de la Sociedad Española de Alergia e Inmunología Clínica (SEAIC) en colaboración con miembros de la Sociedad Española de Anestesia (SEDAR). Se ha realizado una revisión sistemática de la evidencia científica disponible y se proporcionan pautas generales para el manejo de episodios agudos y para la derivación de pacientes con reacciones de hipersensibilidad perioperatoria a los Servicios de Alergología. Se propone un algoritmo práctico para el diagnóstico etiológico y se brindan recomendaciones para el manejo de pacientes con reacciones alérgicas perioperatorias.

The study of anaphylactoid reactions during perioperative procedures and anaesthesia represents a diagnostic challenge for allergists, as many drugs are administered simultaneously, and approximately half of them trigger allergic reactions without a verifiable IgE-mediated mechanism. Recently, mast cell receptor MRGPRX2 has been identified as a cause of pseudo-allergic drug reactions. In this study, we analyse the ability of certain drugs used during perioperative procedures and anaesthesia to induce MRGPRX2-dependent degranulation in human mast cells and sera from patients who experienced an anaphylactoid reaction during the perioperative procedure. Using a β-hexosaminidase release assay, several drugs were seen to cause mast cell degranulation in vitro in comparison with unstimulated cells, but only morphine, vancomycin and cisatracurium specifically triggered this receptor, as assessed by the release of β-hexosaminidase in the control versus the MRGPRX2-silenced cells. The same outcome was seen when measuring degranulation based on the percentage of CD63 expression at identical doses. Unlike that of the healthy controls, the sera of patients who had experienced an anaphylactoid reaction induced mast-cell degranulation. The degranulation ability of these sera decreased when MRGPRX2 was silenced. In conclusion, MRGPRX2 is a candidate for consideration in non-IgE-mediated allergic reactions to some perioperative drugs, reinforcing its role in mast cell responses and their pathophysiology.

Our data prove the existence of common mechanisms of action of OmAb in mast cells and basophils that would explain its effectiveness and rapid effect in chronic urticaria and provide a basis for its use in other diseases mediated by these cells.

Allergic diseases are one of the most prevalent diseases, reaching epidemic proportions in developed countries. An allergic reaction occurs after contact with an environmental protein, such as inhalants allergens (pollen, animal dander, house dust mites), or food proteins. This response is known as part of the type 2 immunity that is counterbalanced by Type 1 immunity and Tregs. Widely used allergen-specific immunotherapy (IT) is a long term treatment to induce such switch from Th2 to Th1 response. However, conventional IT requires multiple allergen injections over a long period of time and is not free of risk of producing allergic reactions. As a consequence, new safer and faster immunotherapeutic methods are required. This review deals with allergen IT using nanoparticles as allergen delivery system that will allow a different way of administration, reduce dose and diminish allergen exposure to IgE bound to mast cells or basophils.