BDKRB2 and hereditary angioedema: Bradykinin is an endogenous substance that causes pain.[15] Since predominant kinin-producing activity is detected in the skin during thermal sweating, bradykinin may play a role in pain during sweating stimulation.[7–10] Icatibant, a bradykinin B2 receptor antagonist, has been approved for the treatment of acute attacks of hereditary angioedema,[14,16] but been off-label for dermal pain associated with sweating stimuli.