Swelling With No Clear Cause
Idiopathic angioedema means repeated episodes of swelling for which no cause can be found after evaluation. It may be histaminergic, which responds to antihistamines, or non-histaminergic, which does not. It is a diagnosis made after other causes are excluded.
Symptoms
Swelling of the lips, eyelids, face, hands or feet that can last one to three days and may occur without hives. Throat swelling is less common but possible.
Diagnosis
Doctors check medicines (especially ACE inhibitors), exposure history and basic lab tests. If hives are absent, C4 and C1 inhibitor testing screens for hereditary and acquired forms. See angioedema causes.
Treatment
The first step is a non-sedating antihistamine, often at a higher dose under medical supervision. If swelling persists, add-on options such as omalizumab may be considered. If antihistamines have no effect, the doctor may look for bradykinin-mediated disease again. Learn about angioedema treatment.
When to Call 911
Call 911 right away if hives or swelling occur with difficulty breathing or swallowing, a tight or closing throat, a swollen tongue, lips or face, wheezing, faintness, or a sudden feeling of impending doom. Use an epinephrine auto-injector first if one has been prescribed to you, then call for emergency help.
When to See a Doctor
See a doctor if your symptoms last more than a few days, keep coming back, cover large areas, or interfere with sleep or daily life. If you would like a specialist’s opinion, Dr. Tiffany Young’s Hives Treatment Center in San Francisco offers online and in-person consultations for idiopathic angioedema.
Frequently Asked Questions About Idiopathic Angioedema
Is idiopathic angioedema dangerous?
Usually not, but throat swelling can be.
Does it go away?
Many people experience fewer episodes over time.
Is it related to chronic hives?
It can be. See chronic hives.
Get Relief for Your Hives
Recurrent swelling is worth a specialist evaluation. Visit our hives treatment page to see the latest treatment options for your outbreak.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis or treatment. If you think you are having a medical emergency, call 911.
