Hereditary Angioedema Presenting With Acute Abdominal Symptoms and Progressive Upper Airway Compromise: A Case Report

Hereditary angioedema (HAE) is a rare but potentially life-threatening disorder that may present with abdominal symptoms and airway compromise, often mimicking surgical or allergic emergencies.We report the case of a 21-year-old female patient who presented to the emergency department with severe abdominal pain, vomiting, and abdominal distension, followed by progressive facial and tongue swelling, muffled voice, and inspiratory stridor during observation.Initial laboratory testing showed no leukocytosis, electrolyte disturbance, or acid-base abnormality, while plain abdominal radiography showed no free intraperitoneal air or obstructive bowel gas pattern.The patient showed no clinical improvement with conventional anaphylaxis management, including epinephrine, corticosteroids, and antihistamines.A history of recurrent abdominal pain episodes, family history of swelling episodes, absence of urticaria or hypotension, and evolving angioedema prompted consideration of hereditary angioedema.Because disease-specific therapy was unavailable, two units of fresh frozen plasma were administered, followed by improvement in abdominal and upper airway symptoms.Endotracheal intubation and surgical intervention were not required.Following stabilization, low serum C4 and C1 esterase inhibitor levels supported the diagnosis of hereditary angioedema type I.This case highlights the diagnostic challenges associated with atypical presentations of hereditary angioedema and emphasizes the importance of early recognition, airway vigilance, and resource-appropriate management in emergency settings.