Tracheal intubation is required in these situations to prevent respiratory arrest and risk of death.Sometimes, the cause is recent exposure to an allergen (e.g. peanuts), but more often it is either idiopathic (unknown) or only weakly correlated to allergen exposure.In hereditary angioedema (HAE), often no direct cause is identifiable, although mild trauma, including dental work and other stimuli, can cause attacks. There is usually no associated itch or urticaria, as it is not an allergic response. Patients with HAE can also have recurrent episodes (often called "attacks") of abdominal pain, usually accompanied by intense vomiting, weakness, and in some cases, watery diarrhea, and an unraised, nonitchy splotchy/swirly rash. These stomach attacks can last one to five days on average and can require hospitalization for aggressive pain management and hydration. Abdominal attacks have also been known to cause a significant increase in the patients white blood cell count, usually in the vicinity of 13,000 to 30,000. As the symptoms begin to diminish, the white count slowly begins to decrease, returning to normal when the attack subsides. As the symptoms and diagnostic tests are almost indistinguishable from an acute abdomen (e.g. perforated appendicitis) it is possible for undiagnosed HAE patients to undergo laparotomy (operations on the abdomen) or laparoscopy (keyhole surgery) that turns out to have been unnecessary.HAE may also cause swelling in a variety of other locations, most commonly the limbs, genitals, neck, throat and face. The pain associated with these swellings varies from mildly uncomfortable to agonizing pain, depending on its location and severity.
See also
Drug-induced angioedema
Gleichs syndrome (unexplained angioedema with high eosinophil counts)
Ruconest (C1-inhibitor)

References
External links

Angioedema at Curlie