These can be detected by flow cytometry, which forms the basis of experimental drug‐induced basophil activation tests.51 In future, basophil activation tests may replace skin tests as the gold standard for making a definitive diagnosis of anaphylaxis, as this assay has the advantage of not being associated with the risk of inducing anaphylaxis during the test.52 Another test that can be carried out in vitro is measurement of drug‐specific IgE levels. Here, IGHE is linked to anaphylaxis.