Drug hypersensitivity reactions (DHRs) are a burden for patients and the health systems, not only due to the increasing prevalence but also to the complexity and severity of the reactions. These reactions are the consequence of different immunological mechanisms that appear after drug-induced activation of effector cells, or activation of inflammatory pathways and the mediators release. These mechanisms can be immunological or non-immunological mediated, and the appearance of new drugs for treatment of oncologic or autoimmune diseases have increased their complexity. Since these arrays of mechanisms can be associated with similar symptoms, a correct endophenotyping is currently a major challenge. Identification of a specific mechanism is a practice of personalized medicine since it can determine the recommendation of avoidance vs. re-exposure to the culprit drug. Indeed, they differ in terms of reoccurrence rate, the effect of dose/exposure rate, and probably the role of pre-medication and desensitization.

This task force aims to get a proper knowledge of different DHR endotypes based on specific biomarkers that will permit discriminating patients within the same phenotype. This will allow developing specific guidelines and recommendations in a consensus document using data from the literature and group’s own experience.