Angioedema without urticaria: Diagnosis and management

Area of Science:

• Immunology
• Genetics
• Pharmacology

Background:

• Angioedema involves nonpitting swelling in subcutaneous and submucosal tissues.
• It is etiologically classified into histaminergic, bradykinin-mediated, or idiopathic types.
• Bradykinin-mediated angioedema typically lacks urticaria, unlike histaminergic angioedema which is often associated with chronic spontaneous urticaria.

Purpose of the Study:

• To differentiate the various etiologies of angioedema.
• To highlight the clinical presentations and underlying mechanisms of different angioedema types.
• To emphasize the importance of personalized management strategies for angioedema patients.

Main Methods:

• Classification of angioedema based on clinical presentation (urticaria presence/absence).
• Identification of underlying causes including genetic mutations (e.g., SERPING1 gene in HAE), autoantibodies, and ACE inhibitor use.
• Diagnostic differentiation based on C1-esterase inhibitor (C1-INH) levels and response to antihistamines.

Main Results:

• Hereditary angioedema (HAE) is a genetic disorder often linked to C1-INH deficiency or normal levels with distinct mutations.
• Acquired C1-INH deficiency is associated with autoimmune or lymphoproliferative disorders.
• ACE inhibitor angioedema presents with specific swelling patterns and resolves after drug cessation.
• Idiopathic angioedema, the most common form, is sub-classified based on response to antihistamines.

Conclusions:

• Accurate diagnosis of angioedema etiology is essential for appropriate management.
• Hereditary angioedema requires consideration of prophylaxis and on-demand therapies.
• Collaborative physician-patient strategies are vital for personalized angioedema care.