What is the mechanism of bradykinin-induced anaphylaxis?

From the Guidelines

Bradykinin-induced anaphylaxis should be treated with immediate administration of epinephrine (0.3-0.5 mg of 1:1000 concentration intramuscularly in the mid-outer thigh for adults; 0.15 mg for children under 30 kg), which should be repeated every 5-15 minutes if symptoms persist, as recommended by the most recent guidelines 1. The treatment of bradykinin-induced anaphylaxis is crucial due to its potential to be life-threatening. According to the 2020 practice parameter update on anaphylaxis, epinephrine is the first-line treatment for anaphylaxis, and its administration should not be delayed 1. Some key points to consider in the treatment of bradykinin-induced anaphylaxis include:

• Discontinuation of ACE inhibitors, if the patient is taking them, as they can increase bradykinin levels by preventing its breakdown 1
• Consideration of Icatibant (30 mg subcutaneously), a bradykinin B2 receptor antagonist, as it may be particularly effective for bradykinin-mediated reactions
• Administration of fresh frozen plasma to provide kininase II to degrade bradykinin
• Supportive care, including oxygen, intravenous fluids, and airway management, is essential in the treatment of bradykinin-induced anaphylaxis The pathophysiology of anaphylaxis, including bradykinin-induced anaphylaxis, involves the activation of various cell types and the release of mediators, such as histamine, bradykinin, and leukotrienes, which can lead to increased vascular permeability, angioedema, and hypotension 1. In the context of bradykinin-induced anaphylaxis, the use of antihistamines and corticosteroids may not be effective, as the reaction is mediated primarily by bradykinin rather than histamine 1. Therefore, the treatment should focus on the administration of epinephrine and other supportive measures to manage the symptoms and prevent further complications.

From the Research

Bradykinin Induced Anaphylaxis

• Anaphylaxis is a life-threatening systemic reaction that can be triggered by various factors, including bradykinin 2
• Bradykinin is a potent inflammatory mediator that can cause vasodilation, vascular leakage, and decreased peripheral vascular resistance, leading to severe hypotension or airway compromise 2
• The bradykinin-forming cascade can be recruited in mast cell-dependent anaphylactic reactions, contributing to the development of severe hypotension or airway compromise 2

Treatment of Anaphylaxis

• Epinephrine (adrenaline) is the first-line treatment for anaphylaxis, and its prompt administration is critical to prevent fatalities 3, 4, 5, 6
• Antihistamines and corticosteroids may be used as adjunctive treatments, but their use should not delay the administration of epinephrine 3, 4, 6
• The use of corticosteroids in anaphylaxis should be revisited, as they may not be effective in preventing uncontrolled reactions or hospital admissions 6

Management of Anaphylaxis

• Removal of the trigger, early administration of intramuscular epinephrine, and supportive care for the patient's airway, breathing, and circulation are essential components of anaphylaxis management 4
• Patients should be monitored for a biphasic reaction, which can occur within 4-12 hours after the initial reaction, depending on risk factors for severe anaphylaxis 4
• Development of an emergency action plan, referral to an allergist, and patient education on avoidance of triggers and appropriate use of an epinephrine auto-injector are crucial for preventing future anaphylactic reactions 4