2 learning resources available for this topic
Urticaria (hives) and angioedema are allergic reactions characterized by raised, itchy wheals on the skin and deeper swelling of mucous membranes, respectively. These conditions can occur together or separately and may be acute (lasting less than 6 weeks) or chronic, with triggers including allergens, medications, infections, or stress.
Both conditions result from mast cell degranulation and histamine release, causing increased vascular permeability and vasodilation. In urticaria, this occurs in the superficial dermis creating wheals, while angioedema involves deeper dermal and subcutaneous tissues, particularly affecting areas with loose connective tissue like the lips, eyelids, and throat.
Diagnosis is primarily clinical based on characteristic appearance and distribution patterns, with acute cases often having identifiable triggers while chronic urticaria frequently remains idiopathic. Emergency management focuses on airway assessment in angioedema cases, while treatment typically involves antihistamines, corticosteroids for severe cases, and epinephrine for anaphylactic reactions.