What Are the Symptoms of Angioedema?

Vascular edema, also known as angioedema, is a rapid, localized swelling of the deeper layers of the skin and mucosa—specifically the subcutaneous and submucosal tissues. Unlike urticaria (hives), which affects the superficial dermis, angioedema involves deeper tissue compartments and often spares the epidermis.

Common clinical manifestations include non-pitting, asymmetrical swelling that typically develops over minutes to hours. The most frequently affected sites are the face—particularly the lips, eyelids, and cheeks—as well as the tongue, pharynx, larynx, and gastrointestinal tract. Swelling of the upper airway can lead to stridor, hoarseness, dysphagia, or respiratory distress, representing a life-threatening emergency. Gastrointestinal involvement may present with acute abdominal pain, nausea, vomiting, or diarrhea due to mucosal edema in the bowel wall.

Notably, angioedema is usually non-pruritic, though mild discomfort or a sensation of tightness or burning may be reported. In hereditary or acquired forms linked to C1 esterase inhibitor deficiency, swelling episodes are often recurrent, spontaneous, and not associated with urticaria or pruritus. Drug-induced cases—especially those triggered by ACE inhibitors—may occur after months or years of stable therapy and carry a higher risk of laryngeal involvement.

Accurate diagnosis hinges on thorough history-taking, physical examination, and selective laboratory testing—including serum C4, C1 inhibitor antigenic and functional levels—to distinguish between allergic, idiopathic, drug-induced, and complement-mediated subtypes. Prompt recognition and appropriate management are critical, particularly when airway compromise is suspected.