What is angioedema and what causes it?
Angioedema is swelling that occurs when fluid accumulates in the deep layers of your skin. While there are several types of angioedema with different causes, the swelling is usually mediated by the following:
- Histamine: released during an allergic reaction or due to infections, autoimmune conditions, or mast cell activation from an unknown cause
- Bradykinin: overproduced in the skin in response to a medication or a genetic protein deficiency
The various causes of angioedema include:
Allergic Angioedema
Angioedema develops due to an allergic reaction in 90% of all cases, although the trigger or allergen may not be evident. Allergic angioedema usually occurs together with hives.
ACE inhibitor medication-induced angioedema
This type of angioedema occurs in 4-8% of patients. The swelling may develop over a period of 24-36 hours after taking the medication and resolve within a few days. The time course is variable, however, as the swelling may appear weeks or even years after starting the medication.
Idiopathic angioedema
In this type of angioedema, the swelling persists for six weeks or longer. In many cases, the cause isn’t known and hives are present some of the time.
Other types of angioedema
Hereditary angioedema and acquired angioedema are both rare causes of swelling that results from a deficiency in a specific protein called C1-esterase inhibitor. The underlying problem can be due to a genetic or autoimmune condition.
What allergens commonly cause acute angioedema?
Acute allergic angioedema occurs within minutes to several hours after you’re exposed to the allergen. The most common causes are:
- Food allergies: nuts, shellfish, milk, eggs, soy, and wheat
- Drugs: penicillin: nonsteroidal anti-inflammatory drugs, sulfa drugs
- Insect venoms: bees, hornets, wasps, yellow jackets, fire ants
- Rubber latex: gloves, balloons, condoms
What are the symptoms of angioedema?
Angioedema is essentially deep skin swelling that develops rapidly and is similar to large hives, except that hives occur on the surface of the skin. Patches of angioedema may be large, thick, and often asymmetric. The area affected by angioedema may feel warm, burning, painful, or itchy.
The swelling often appears on your face, especially around your eyes, lips, tongue, and cheeks, but may also involve your hands, feet, and throat. Angioedema usually doesn't last longer than 72 hours; then the area goes back to its normal appearance.
How is angioedema treated?
A severe and sudden attack of angioedema can signal the onset of a life-threatening allergic reaction called anaphylaxis. If you have trouble breathing, have a weak or rapid pulse, or feel dizzy or confused, call 9-1-1 for immediate medical attention. Also, use your epinephrine auto-injector if you have one.
Angioedema can affect your throat and interfere with your ability to breathe, even if it's not the start of anaphylaxis. This should also be treated as a potential emergency, so you should seek medical attention.
Treatment for acute allergic angioedema focuses on relieving symptoms with medications and determining the cause of your reaction. Your treatment is always individualized based on your specific allergy, but it may include medications such as:
- Antihistamines: long-acting and short-acting antihistamines are the first-line treatment
- Steroids: used for a short time when antihistamines alone don’t control your symptoms
- Immunosuppressants: when steroids don’t reduce symptoms or can’t be tapered down, these medications are considered
- Omalizumab: an anti-IgE monoclonal antibody that may help chronic idiopathic angioedema
If you’ve ever had angioedema, please protect your health and get treatment from the experts. Schedule an appointment at the Song Institute of Allergy, Asthma and Immunology -- just call the office or book it online.
