[The multiple etiologies of angioedema]

Area of Science:

• Immunology
• Pharmacology
• Genetics

Context:

• Angioedema is a common condition with diverse triggers.
• Histamine-mediated angioedema often co-occurs with urticaria.
• Bradykinin is implicated in specific angioedema subtypes, notably those related to ACE inhibitors and C1-inhibitor deficiency.

Purpose:

• To differentiate angioedema subtypes based on their underlying pathophysiology.
• To highlight the distinct treatment responses between histamine- and bradykinin-mediated angioedemas.

Summary:

• Angioedemas associated with urticaria are typically histamine-mediated, responding to antihistamines and adrenaline.
• Drug-induced (e.g., NSAID), physical, and recurrent idiopathic angioedemas often fall under the histamine-mediated category.
• Angioedemas linked to ACE inhibitors, ARBs, or C1-inhibitor deficiency (hereditary or acquired) are likely bradykinin-mediated, presenting without urticaria and unresponsive to standard treatments.

Impact:

• Clarifies diagnostic and therapeutic approaches for different angioedema types.
• Emphasizes the importance of identifying the specific angioedema pathway for appropriate clinical management.
• Guides clinicians in selecting treatments based on the suspected etiological mechanism, improving patient outcomes.