Angioedema Phenotypes: Disease Expression and Classification.

Area of Science:

• Immunology
• Dermatology
• Genetics

Background:

• Angioedema presents heterogeneously, complicating diagnosis and treatment.
• Distinguishing angioedema with wheals (urticaria) from angioedema without wheals is clinically significant.
• Previous classifications focused on urticaria-associated angioedema; the HAWK group (2014) proposed a distinct classification for angioedema without wheals.

Purpose of the Study:

• To review the latest classification of angioedema without wheals by the HAWK group.
• To detail the pathophysiology, triggers, and clinical features of distinct angioedema phenotypes.
• To provide a comprehensive overview of hereditary and acquired angioedema types.

Main Methods:

• Review of the HAWK group consensus classification (2014).
• Analysis of pathophysiology, involved mediators, and triggers for each angioedema type.
• Detailed examination of clinical presentations for each phenotype.

Main Results:

• The HAWK classification categorizes angioedema without wheals into distinct hereditary and acquired types.
• Hereditary angioedema includes C1-INH deficiency, normal C1-INH with Factor XII mutations, and unknown origin.
• Acquired angioedema encompasses C1-INH deficiency, ACE inhibitor-induced, idiopathic histaminergic, and idiopathic non-histaminergic forms.

Conclusions:

• The HAWK classification offers a comprehensive framework for understanding angioedema without wheals.
• Recognizing specific phenotypes is crucial for accurate diagnosis and tailored therapeutic strategies.
• Further research into the underlying mechanisms of idiopathic angioedema types is warranted.