What Causes Angioedema?

Are There Different Types of Angioedema?

Angioneurotic Edema (now called Angioedema) is swelling in the dermis or lower layer of skin, usually occurring in the facial area involving the lips, throat, tongue, and around the eyes, stomach, or arms and legs. At times, the genitals may swell. It results from a leaking of fluid in the areas of loose tissue, especially the throat and face. It becomes more critical when it occurs in the laryngeal area as it may occlude the air passage. This creates a possible asphyxiation problem which results in an immediate medical emergency.  This may frighten the patient and cause them to hyperventilate which compounds the oxygenation of the blood in the lungs. Blood pressure may drop rapidly, adding to the medical emergency. The causative factor is usually an allergic reaction, but sometimes it may be inherited.

As stated above, angioedema has two probable causes. The first and most probable cause, is an allergic reaction. The second and least probable, is an inherited trait.  But there are actually four types: allergic, drug induced, idiopathic (meaning unknown cause), or hereditary. At any rate, regardless of the actual cause, the condition is very disconcerting to the patient, and at times, may actually lead to a condition called anaphylactic shock, which is an hypersensitivity reaction to the ingestion or injection of a substance (a protein or drug) resulting from prior contact with that same or  a substance with similar compound. The symptoms may lead to swelling of the throat and laryngeal area, as well as other areas. Each consecutive time that the patient is exposed to the allergin or the substance that initiates the angioedema, the reaction becomes more enhanced and more likely to lead to anaphylactic shock.

The condition of angioedema is similar to the common hives which affects the superficial layer of the skin or dermis. However, angioedema does not only involve the upper layers of the skin, but all of the deeper layers, in addition to the superficial layer.

What are the most common causes of angioedema due to allergy?

Insect bites, venom from snakes, ants, bees/wasps, food, drugs (even over-the-counter drugs), air-borne pollen, peanuts, peanut butter, latex allergy, and certain soaps, all have been known to initiate angioedema. Usually this edema is not chronic, nor long-term and can quickly be reversed once the cause is determined. It rarely lasts but a short period of time but may last up to three days. Avoidance in the future of the cause or the allergen which initiated the response, eliminates future problems in most cases of allergy-induced angioedema.

There are certain drugs which are more likely to cause angioedema than others. In most cases, a prescription change in that medication will solve the problem. On that list are ACE inhibitors or any other drugs which are used to treat high blood pressure. Research has found that approximately one third of the angioedema cases are a result of ACE inhibitors. Some of the over-the-counter drugs may also induce angioedema, such as Tylenol. Aspirin, Ibuprofin, Alleve, Motrin, and others. (NSAIDS) or non-steroidal anti-inflammatory drugs are high on the list.

Idiopathic (unknown cause) angioedema for which the cause is not clear, even after the doctor examines for all causes, may remain unknown.

Hereditary angioedema (HAE) of course is inherited. It is usually an extended family trait and a less than normal amount of what is called the C1 inhibitor protein. The onset of this swelling is sporadic and will come and go over time. HAE is usually suspected if the edema comes and goes for no apparent reason. Antihistamines and/or steroids are used to treat this situation.

What are the Treatments for Angioedema?

Histaminic angioedema can be treated with antihistamines, epinephrine, or steroids. Over-the-counter anti-inflammatory drugs may be useful. Inherited angioedema is usually treated with a C1 esterase inhibitor, or sometimes even fresh frozen plasma. Angioedema resulting from ACE inhibitors is treated by stopping or changing the drug used for high blood pressure.

Since the odds are about one in ten thousand that any one person may incur angioedema, the reader should not be too concerned about having to face this problem. But should the need arise, or you have swelling caused by an unknown source, it is advisable to visit your physician immediately. And if you feel a tightness of the throat and/or larynx, go to the emergency room immediately. In the greatest majority of cases, medication such as that in the Epi-pen, will resolve the problem rather quickly. It may be advisable to always have an Epi-pen available, or some antihistamines or over-the-counter anti-inflammatory drugs. Once you learn the source of the cause of this swelling, you will be better able to manage it or completely avoid it in the future.

Today’s Dentist, DDS, FAGD

Life Member of American Dental Association, Emeritus Fellow of Academy of General Dentistry, American Association of Implant Dentists