Editor’s comment: Frequent asthma exacerbations result in a decrease in respiratory function; thus, preventing these exacerbations is important in clinical practice. In this study, Yokoyama et al. examined regional differences in the incidence of asthma exacerbations in Japan, using a nationwide health insurance claims database. They found that the incidence rate of asthma exacerbations — which are the composite outcome of hospitalization, injectable corticosteroid prescription, and oral corticosteroid burst— varied by region, with the difference found to be more than sixfold.

Editor’s comment: Autoantibodies against IgE and its high-affinity receptor, FcεRIα, are key factors in developing type IIb autoimmune chronic spontaneous urticaria. In this study, Koga et al. developed a new method, using AlphaCL (the amplified luminescence proximity homogeneous assay by cross-linking) to detect anti-IgE and anti-FcεRIα autoantibodies with IgE- and FcεRIα-crosslinking abilities in the sera of patients with type IIb autoimmune chronic spontaneous urticaria. This method seems to be a promising diagnostic tool for these patients.

Editor’s comment: Natto, a traditional Japanese fermented soybean food, has been reported to occasionally cause anaphylaxis and urticaria characterized by late onset, with symptoms occurring 5–12 h after ingestion. The late onset makes it challenging to diagnose natto-induced hypersensitivity from medical interviews. In this study, Fukuda et al. found the basophil activation test to be useful in diagnosing natto-induced hypersensitivity.