International research efforts significantly advanced our understanding of the local inflammatory mechanisms of various allergic reactions, through the blister fluid (BF) analysis from spontaneous and experimental suction blisters. The BF is an important source of immunoglobulins, cytotoxic proteins, cytokines, chemokines, mediators, enzymes, mRNAs, and exosomes, with the differential expression in various allergic reactions.  Immediate and delayed allergic reactions were characterized by local contribution of effector cells, mediators and cytokines. BF research in severe drug reactions (SDR) provided insights into BF T cell clonality, the contribution of cytotoxic peptides and cytokines in the blistering processes. As a result, several candidate biomarkers of local inflammation in SDR were identified. BF analysis can provide valuable information, in addition to skin histology, for the assessment of disease severity, prognosis, differential diagnosis and potential treatment options.  The advantages of BD analysis are the ease of sample collection at different stages of allergic reactions whereas the limitations include low sample volume and the difficulty of interpretation due to a considerable biological variation between the patients. Since early BF studies, there have been a few large prospective studies but mostly small case series and case reports using BF data. There was a heterogeneity in patient selection criteria and BF analysis protocols, hindering the clinical use of BF in allergic diseases, including SDR. Additionally, most studies were carried out before the widespread use of ‘omics’ technologies, single cell analysis, and machine learning algorithms.  The purpose of this application is to revisit and systematically review the previous BF research, to standardize the BF analysis procedures, to present the research agenda and clinical recommendations for the use of BF analysis in various allergic reactions, that can harmonize future research efforts and inform clinical decisions.

Chair: Elena Borzova
Secretary: Knut Brockow