Idiopathic Angioedema

Idiopathic angioedema is a broad class of angioedema in which swelling attacks happen regularly without an identifiable cause. This type of angioedema is thought to occur in 15–20% of the cases.


Although there is no known cause for the swelling associated with idiopathic angioedema, certain factors, including stress or an infection, are known to act as potential attack triggers.

In an estimated 30–50% of the cases, idiopathic angioedema may be associated with an underlying autoimmune disease, such as systemic lupus erythematosus (SLE).


Swelling in this form of angioedema is characterized by smooth welts of raised or enlarged skin and is usually not accompanied by hives, or urticaria.

Unlike other forms of angioedema in which swelling occurs suddenly as part of an allergic reaction, swelling in idiopathic angioedema is chronic, recurring regularly on a long-term basis for no apparent reason.


Idiopathic angioedema can be treated with allergy medications, such as antihistamines, corticosteroids, and immunosuppressive agents.

Medications used to treat hereditary angioedema, such as Kalbitor (ecallantide) and Firazyr (icatibant), can also help prevent angioedema attacks even if its trigger is unknown.

Cannabis, which has been shown to have anti-inflammatory properties, may also be an option to treat idiopathic angioedema. In a case study published in 2015, a patient with chronic idiopathic angioedema achieved relief from his symptoms with medical cannabis. However, more research is needed before cannabis can be used in the clinic as a treatment for idiopathic angioedema.

In a life-threatening situation, where swelling in the throat or mouth has blocked the airway, an EpiPen (epinephrine) can be used to quickly treat swelling.


Last updated: Dec. 16, 2021, by Teresa Carvalho MSc


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