Miyata et al. describe hereditary angioedema in detail, including recently identified gene mutations that show that bradykinin plays a central role in this edema.

Matsuda et al. review the similarities and differences between CAPS and Schnitzler syndrome, in which IL-1β is thought to play a central role in autoinflammatory reactions with urticarial rash. In CAPS, the usefulness of treatment targeting IL-1 is well established, while in Schnitzler syndrome, there is currently no established treatment. They propose a treatment algorithm in which colchicine is the first-line drug, to be introduced before IL-1-targeted therapy.

Saini introduces the possibility that the behavior of basophils in the blood changes when IgE-targeted therapy is successful and that therefore the number of basophils in the blood may be an indicator of the activity of urticaria.

By testing the effects of omalizumab as well as other biologics on silencing or depleting mast cells or for neutralizing mast cell-derived mediators, Elieh-Ali-Komi et al. suggest here that the role of mast cells in urticaria will be clarified.